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2024-09-21Merge tag 'sched_ext-for-6.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext support from Tejun Heo: "This implements a new scheduler class called ‘ext_sched_class’, or sched_ext, which allows scheduling policies to be implemented as BPF programs. The goals of this are: - Ease of experimentation and exploration: Enabling rapid iteration of new scheduling policies. - Customization: Building application-specific schedulers which implement policies that are not applicable to general-purpose schedulers. - Rapid scheduler deployments: Non-disruptive swap outs of scheduling policies in production environments" See individual commits for more documentation, but also the cover letter for the latest series: Link: https://lore.kernel.org/all/20240618212056.2833381-1-tj@kernel.org/ * tag 'sched_ext-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (110 commits) sched: Move update_other_load_avgs() to kernel/sched/pelt.c sched_ext: Don't trigger ops.quiescent/runnable() on migrations sched_ext: Synchronize bypass state changes with rq lock scx_qmap: Implement highpri boosting sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq() sched_ext: Compact struct bpf_iter_scx_dsq_kern sched_ext: Replace consume_local_task() with move_local_task_to_local_dsq() sched_ext: Move consume_local_task() upward sched_ext: Move sanity check and dsq_mod_nr() into task_unlink_from_dsq() sched_ext: Reorder args for consume_local/remote_task() sched_ext: Restructure dispatch_to_local_dsq() sched_ext: Fix processs_ddsp_deferred_locals() by unifying DTL_INVALID handling sched_ext: Make find_dsq_for_dispatch() handle SCX_DSQ_LOCAL_ON sched_ext: Refactor consume_remote_task() sched_ext: Rename scx_kfunc_set_sleepable to unlocked and relocate sched_ext: Add missing static to scx_dump_data sched_ext: Add missing static to scx_has_op[] sched_ext: Temporarily work around pick_task_scx() being called without balance_scx() sched_ext: Add a cgroup scheduler which uses flattened hierarchy sched_ext: Add cgroup support ...
2024-09-19Merge tag 'sched-core-2024-09-19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot de Oliveira's last major contribution to the kernel: "SCHED_DEADLINE servers can help fixing starvation issues of low priority tasks (e.g., SCHED_OTHER) when higher priority tasks monopolize CPU cycles. Today we have RT Throttling; DEADLINE servers should be able to replace and improve that." (Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes, Youssef Esmat, Huang Shijie) - Preparatory changes for sched_ext integration: - Use set_next_task(.first) where required - Fix up set_next_task() implementations - Clean up DL server vs. core sched - Split up put_prev_task_balance() - Rework pick_next_task() - Combine the last put_prev_task() and the first set_next_task() - Rework dl_server - Add put_prev_task(.next) (Peter Zijlstra, with a fix by Tejun Heo) - Complete the EEVDF transition and refine EEVDF scheduling: - Implement delayed dequeue - Allow shorter slices to wakeup-preempt - Use sched_attr::sched_runtime to set request/slice suggestion - Document the new feature flags - Remove unused and duplicate-functionality fields - Simplify & unify pick_next_task_fair() - Misc debuggability enhancements (Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann, Valentin Schneider and Chuyi Zhou) - Initialize the vruntime of a new task when it is first enqueued, resulting in significant decrease in latency of newly woken tasks (Zhang Qiao) - Introduce SM_IDLE and an idle re-entry fast-path in __schedule() (K Prateek Nayak, Peter Zijlstra) - Clean up and clarify the usage of Clean up usage of rt_task() (Qais Yousef) - Preempt SCHED_IDLE entities in strict cgroup hierarchies (Tianchen Ding) - Clarify the documentation of time units for deadline scheduler parameters (Christian Loehle) - Remove the HZ_BW chicken-bit feature flag introduced a year ago, the original change seems to be working fine (Phil Auld) - Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie, Peilin He, Qais Yousefm and Vincent Guittot) * tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits) sched/cpufreq: Use NSEC_PER_MSEC for deadline task cpufreq/cppc: Use NSEC_PER_MSEC for deadline task sched/deadline: Clarify nanoseconds in uapi sched/deadline: Convert schedtool example to chrt sched/debug: Fix the runnable tasks output sched: Fix sched_delayed vs sched_core kernel/sched: Fix util_est accounting for DELAY_DEQUEUE kthread: Fix task state in kthread worker if being frozen sched/pelt: Use rq_clock_task() for hw_pressure sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule() sched: Add put_prev_task(.next) sched: Rework dl_server sched: Combine the last put_prev_task() and the first set_next_task() sched: Rework pick_next_task() sched: Split up put_prev_task_balance() sched: Clean up DL server vs core sched sched: Fixup set_next_task() implementations sched: Use set_next_task(.first) where required sched/fair: Properly deactivate sched_delayed task upon class change ...
2024-09-03Merge branch 'tip/sched/core' into for-6.12Tejun Heo
- Resolve trivial context conflicts from dl_server clearing being moved around. - Add @next to put_prev_task_scx() and @prev to pick_next_task_scx() to match sched/core. - Merge sched_class->switch_class() addition from sched_ext with tip/sched/core changes in __pick_next_task(). - Make pick_next_task_scx() call put_prev_task_scx() to emulate the previous behavior where sched_class->put_prev_task() was called before sched_class->pick_next_task(). While this makes sched_ext build and function, the behavior is not in line with other sched classes. The follow-up patches will address the discrepancies and remove sched_class->switch_class(). Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-03sched: Clean up DL server vs core schedPeter Zijlstra
Abide by the simple rule: pick_next_task() := pick_task() + set_next_task(.first = true) This allows us to trivially get rid of server_pick_next() and things collapse nicely. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20240813224015.837303391@infradead.org
2024-08-20Merge branch 'tip/sched/core' into for-6.12Tejun Heo
To receive 863ccdbb918a ("sched: Allow sched_class::dequeue_task() to fail") which makes sched_class.dequeue_task() return bool instead of void. This leads to compile breakage and will be fixed by a follow-up patch. Signed-off-by: Tejun Heo <tj@kernel.org>
2024-08-17sched/eevdf: Propagate min_slice up the cgroup hierarchyPeter Zijlstra
In the absence of an explicit cgroup slice configureation, make mixed slice length work with cgroups by propagating the min_slice up the hierarchy. This ensures the cgroup entity gets timely service to service its entities that have this timing constraint set on them. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Valentin Schneider <vschneid@redhat.com> Link: https://lkml.kernel.org/r/20240727105030.948188417@infradead.org
2024-08-17sched/eevdf: Use sched_attr::sched_runtime to set request/slice suggestionPeter Zijlstra
Allow applications to directly set a suggested request/slice length using sched_attr::sched_runtime. The implementation clamps the value to: 0.1[ms] <= slice <= 100[ms] which is 1/10 the size of HZ=1000 and 10 times the size of HZ=100. Applications should strive to use their periodic runtime at a high confidence interval (95%+) as the target slice. Using a smaller slice will introduce undue preemptions, while using a larger value will increase latency. For all the following examples assume a scheduling quantum of 8, and for consistency all examples have W=4: {A,B,C,D}(w=1,r=8): ABCD... +---+---+---+--- t=0, V=1.5 t=1, V=3.5 A |------< A |------< B |------< B |------< C |------< C |------< D |------< D |------< ---+*------+-------+--- ---+--*----+-------+--- t=2, V=5.5 t=3, V=7.5 A |------< A |------< B |------< B |------< C |------< C |------< D |------< D |------< ---+----*--+-------+--- ---+------*+-------+--- Note: 4 identical tasks in FIFO order ~~~ {A,B}(w=1,r=16) C(w=2,r=16) AACCBBCC... +---+---+---+--- t=0, V=1.25 t=2, V=5.25 A |--------------< A |--------------< B |--------------< B |--------------< C |------< C |------< ---+*------+-------+--- ---+----*--+-------+--- t=4, V=8.25 t=6, V=12.25 A |--------------< A |--------------< B |--------------< B |--------------< C |------< C |------< ---+-------*-------+--- ---+-------+---*---+--- Note: 1 heavy task -- because q=8, double r such that the deadline of the w=2 task doesn't go below q. Note: observe the full schedule becomes: W*max(r_i/w_i) = 4*2q = 8q in length. Note: the period of the heavy task is half the full period at: W*(r_i/w_i) = 4*(2q/2) = 4q ~~~ {A,C,D}(w=1,r=16) B(w=1,r=8): BAACCBDD... +---+---+---+--- t=0, V=1.5 t=1, V=3.5 A |--------------< A |---------------< B |------< B |------< C |--------------< C |--------------< D |--------------< D |--------------< ---+*------+-------+--- ---+--*----+-------+--- t=3, V=7.5 t=5, V=11.5 A |---------------< A |---------------< B |------< B |------< C |--------------< C |--------------< D |--------------< D |--------------< ---+------*+-------+--- ---+-------+--*----+--- t=6, V=13.5 A |---------------< B |------< C |--------------< D |--------------< ---+-------+----*--+--- Note: 1 short task -- again double r so that the deadline of the short task won't be below q. Made B short because its not the leftmost task, but is eligible with the 0,1,2,3 spread. Note: like with the heavy task, the period of the short task observes: W*(r_i/w_i) = 4*(1q/1) = 4q ~~~ A(w=1,r=16) B(w=1,r=8) C(w=2,r=16) BCCAABCC... +---+---+---+--- t=0, V=1.25 t=1, V=3.25 A |--------------< A |--------------< B |------< B |------< C |------< C |------< ---+*------+-------+--- ---+--*----+-------+--- t=3, V=7.25 t=5, V=11.25 A |--------------< A |--------------< B |------< B |------< C |------< C |------< ---+------*+-------+--- ---+-------+--*----+--- t=6, V=13.25 A |--------------< B |------< C |------< ---+-------+----*--+--- Note: 1 heavy and 1 short task -- combine them all. Note: both the short and heavy task end up with a period of 4q ~~~ A(w=1,r=16) B(w=2,r=16) C(w=1,r=8) BBCAABBC... +---+---+---+--- t=0, V=1 t=2, V=5 A |--------------< A |--------------< B |------< B |------< C |------< C |------< ---+*------+-------+--- ---+----*--+-------+--- t=3, V=7 t=5, V=11 A |--------------< A |--------------< B |------< B |------< C |------< C |------< ---+------*+-------+--- ---+-------+--*----+--- t=7, V=15 A |--------------< B |------< C |------< ---+-------+------*+--- Note: as before but permuted ~~~ From all this it can be deduced that, for the steady state: - the total period (P) of a schedule is: W*max(r_i/w_i) - the average period of a task is: W*(r_i/w_i) - each task obtains the fair share: w_i/W of each full period P Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Valentin Schneider <vschneid@redhat.com> Link: https://lkml.kernel.org/r/20240727105030.842834421@infradead.org
2024-08-17sched/fair: Avoid re-setting virtual deadline on 'migrations'Peter Zijlstra
During OSPM24 Youssef noted that migrations are re-setting the virtual deadline. Notably everything that does a dequeue-enqueue, like setting nice, changing preferred numa-node, and a myriad of other random crap, will cause this to happen. This shouldn't be. Preserve the relative virtual deadline across such dequeue/enqueue cycles. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <vschneid@redhat.com> Tested-by: Valentin Schneider <vschneid@redhat.com> Link: https://lkml.kernel.org/r/20240727105030.625119246@infradead.org
2024-08-17sched,freezer: Mark TASK_FROZEN specialPeter Zijlstra
The special task states are those that do not suffer spurious wakeups, TASK_FROZEN is very much one of those, mark it as such. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <vschneid@redhat.com> Tested-by: Valentin Schneider <vschneid@redhat.com> Link: https://lkml.kernel.org/r/20240727105029.998329901@infradead.org
2024-08-17sched: Prepare generic code for delayed dequeuePeter Zijlstra
While most of the delayed dequeue code can be done inside the sched_class itself, there is one location where we do not have an appropriate hook, namely ttwu_runnable(). Add an ENQUEUE_DELAYED call to the on_rq path to deal with waking delayed dequeue tasks. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <vschneid@redhat.com> Tested-by: Valentin Schneider <vschneid@redhat.com> Link: https://lkml.kernel.org/r/20240727105029.200000445@infradead.org
2024-08-04Merge branch 'sched/core' of ↵Tejun Heo
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into for-6.12 Pull tip/sched/core to resolve the following four conflicts. While 2-4 are simple context conflicts, 1 is a bit subtle and easy to resolve incorrectly. 1. 2c8d046d5d51 ("sched: Add normal_policy()") vs. faa42d29419d ("sched/fair: Make SCHED_IDLE entity be preempted in strict hierarchy") The former converts direct test on p->policy to use the helper normal_policy(). The latter moves the p->policy test to a different location. Resolve by converting the test on p->plicy in the new location to use normal_policy(). 2. a7a9fc549293 ("sched_ext: Add boilerplate for extensible scheduler class") vs. a110a81c52a9 ("sched/deadline: Deferrable dl server") Both add calls to put_prev_task_idle() and set_next_task_idle(). Simple context conflict. Resolve by taking changes from both. 3. a7a9fc549293 ("sched_ext: Add boilerplate for extensible scheduler class") vs. c245910049d0 ("sched/core: Add clearing of ->dl_server in put_prev_task_balance()") The former changes for_each_class() itertion to use for_each_active_class(). The latter moves away the adjacent dl_server handling code. Simple context conflict. Resolve by taking changes from both. 4. 60c27fb59f6c ("sched_ext: Implement sched_ext_ops.cpu_online/offline()") vs. 31b164e2e4af ("sched/smt: Introduce sched_smt_present_inc/dec() helper") 2f027354122f ("sched/core: Introduce sched_set_rq_on/offline() helper") The former adds scx_rq_deactivate() call. The latter two change code around it. Simple context conflict. Resolve by taking changes from both. Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-30cgroup/cpuset: Remove cpuset_slab_spread_rotorXiu Jianfeng
Since the SLAB implementation was removed in v6.8, so the cpuset_slab_spread_rotor is no longer used and can be removed. Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Reviewed-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-30Merge tag 'v6.11-rc1' into for-6.12Tejun Heo
Linux 6.11-rc1
2024-07-29sched/core: Fix picking of tasks for core scheduling with DL serverJoel Fernandes (Google)
* Use simple CFS pick_task for DL pick_task DL server's pick_task calls CFS's pick_next_task_fair(), this is wrong because core scheduling's pick_task only calls CFS's pick_task() for evaluation / checking of the CFS task (comparing across CPUs), not for actually affirmatively picking the next task. This causes RB tree corruption issues in CFS that were found by syzbot. * Make pick_task_fair clear DL server A DL task pick might set ->dl_server, but it is possible the task will never run (say the other HT has a stop task). If the CFS task is picked in the future directly (say without DL server), ->dl_server will be set. So clear it in pick_task_fair(). This fixes the KASAN issue reported by syzbot in set_next_entity(). (DL refactoring suggestions by Vineeth Pillai). Reported-by: Suleiman Souhlal <suleiman@google.com> Signed-off-by: "Joel Fernandes (Google)" <joel@joelfernandes.org> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vineeth Pillai <vineeth@bitbyteword.org> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/b10489ab1f03d23e08e6097acea47442e7d6466f.1716811044.git.bristot@kernel.org
2024-07-29sched/deadline: Deferrable dl serverDaniel Bristot de Oliveira
Among the motivations for the DL servers is the real-time throttling mechanism. This mechanism works by throttling the rt_rq after running for a long period without leaving space for fair tasks. The base dl server avoids this problem by boosting fair tasks instead of throttling the rt_rq. The point is that it boosts without waiting for potential starvation, causing some non-intuitive cases. For example, an IRQ dispatches two tasks on an idle system, a fair and an RT. The DL server will be activated, running the fair task before the RT one. This problem can be avoided by deferring the dl server activation. By setting the defer option, the dl_server will dispatch an SCHED_DEADLINE reservation with replenished runtime, but throttled. The dl_timer will be set for the defer time at (period - runtime) ns from start time. Thus boosting the fair rq at defer time. If the fair scheduler has the opportunity to run while waiting for defer time, the dl server runtime will be consumed. If the runtime is completely consumed before the defer time, the server will be replenished while still in a throttled state. Then, the dl_timer will be reset to the new defer time If the fair server reaches the defer time without consuming its runtime, the server will start running, following CBS rules (thus without breaking SCHED_DEADLINE). Then the server will continue the running state (without deferring) until it fair tasks are able to execute as regular fair scheduler (end of the starvation). Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/dd175943c72533cd9f0b87767c6499204879cc38.1716811044.git.bristot@kernel.org
2024-07-29sched/deadline: Comment sched_dl_entity::dl_server variableDaniel Bristot de Oliveira
Add an explanation for the newly added variable. Fixes: 63ba8422f876 ("sched/deadline: Introduce deadline servers") Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Juri Lelli <juri.lelli@redhat.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/147f7aa8cb8fd925f36aa8059af6a35aad08b45a.1716811044.git.bristot@kernel.org
2024-07-21Merge tag 'mm-nonmm-stable-2024-07-21-15-07' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - In the series "treewide: Refactor heap related implementation", Kuan-Wei Chiu has significantly reworked the min_heap library code and has taught bcachefs to use the new more generic implementation. - Yury Norov's series "Cleanup cpumask.h inclusion in core headers" reworks the cpumask and nodemask headers to make things generally more rational. - Kuan-Wei Chiu has sent along some maintenance work against our sorting library code in the series "lib/sort: Optimizations and cleanups". - More library maintainance work from Christophe Jaillet in the series "Remove usage of the deprecated ida_simple_xx() API". - Ryusuke Konishi continues with the nilfs2 fixes and clanups in the series "nilfs2: eliminate the call to inode_attach_wb()". - Kuan-Ying Lee has some fixes to the gdb scripts in the series "Fix GDB command error". - Plus the usual shower of singleton patches all over the place. Please see the relevant changelogs for details. * tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (98 commits) ia64: scrub ia64 from poison.h watchdog/perf: properly initialize the turbo mode timestamp and rearm counter tsacct: replace strncpy() with strscpy() lib/bch.c: use swap() to improve code test_bpf: convert comma to semicolon init/modpost: conditionally check section mismatch to __meminit* init: remove unused __MEMINIT* macros nilfs2: Constify struct kobj_type nilfs2: avoid undefined behavior in nilfs_cnt32_ge macro math: rational: add missing MODULE_DESCRIPTION() macro lib/zlib: add missing MODULE_DESCRIPTION() macro fs: ufs: add MODULE_DESCRIPTION() lib/rbtree.c: fix the example typo ocfs2: add bounds checking to ocfs2_check_dir_entry() fs: add kernel-doc comments to ocfs2_prepare_orphan_dir() coredump: simplify zap_process() selftests/fpu: add missing MODULE_DESCRIPTION() macro compiler.h: simplify data_race() macro build-id: require program headers to be right after ELF header resource: add missing MODULE_DESCRIPTION() ...
2024-07-21Merge tag 'mm-stable-2024-07-21-14-50' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - In the series "mm: Avoid possible overflows in dirty throttling" Jan Kara addresses a couple of issues in the writeback throttling code. These fixes are also targetted at -stable kernels. - Ryusuke Konishi's series "nilfs2: fix potential issues related to reserved inodes" does that. This should actually be in the mm-nonmm-stable tree, along with the many other nilfs2 patches. My bad. - More folio conversions from Kefeng Wang in the series "mm: convert to folio_alloc_mpol()" - Kemeng Shi has sent some cleanups to the writeback code in the series "Add helper functions to remove repeated code and improve readability of cgroup writeback" - Kairui Song has made the swap code a little smaller and a little faster in the series "mm/swap: clean up and optimize swap cache index". - In the series "mm/memory: cleanly support zeropage in vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David Hildenbrand has reworked the rather sketchy handling of the use of the zeropage in MAP_SHARED mappings. I don't see any runtime effects here - more a cleanup/understandability/maintainablity thing. - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of higher addresses, for aarch64. The (poorly named) series is "Restructure va_high_addr_switch". - The core TLB handling code gets some cleanups and possible slight optimizations in Bang Li's series "Add update_mmu_tlb_range() to simplify code". - Jane Chu has improved the handling of our fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the series "Enhance soft hwpoison handling and injection". - Jeff Johnson has sent a billion patches everywhere to add MODULE_DESCRIPTION() to everything. Some landed in this pull. - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has simplified migration's use of hardware-offload memory copying. - Yosry Ahmed performs more folio API conversions in his series "mm: zswap: trivial folio conversions". - In the series "large folios swap-in: handle refault cases first", Chuanhua Han inches us forward in the handling of large pages in the swap code. This is a cleanup and optimization, working toward the end objective of full support of large folio swapin/out. - In the series "mm,swap: cleanup VMA based swap readahead window calculation", Huang Ying has contributed some cleanups and a possible fixlet to his VMA based swap readahead code. - In the series "add mTHP support for anonymous shmem" Baolin Wang has taught anonymous shmem mappings to use multisize THP. By default this is a no-op - users must opt in vis sysfs controls. Dramatic improvements in pagefault latency are realized. - David Hildenbrand has some cleanups to our remaining use of page_mapcount() in the series "fs/proc: move page_mapcount() to fs/proc/internal.h". - David also has some highmem accounting cleanups in the series "mm/highmem: don't track highmem pages manually". - Build-time fixes and cleanups from John Hubbard in the series "cleanups, fixes, and progress towards avoiding "make headers"". - Cleanups and consolidation of the core pagemap handling from Barry Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers and utilize them". - Lance Yang's series "Reclaim lazyfree THP without splitting" has reduced the latency of the reclaim of pmd-mapped THPs under fairly common circumstances. A 10x speedup is seen in a microbenchmark. It does this by punting to aother CPU but I guess that's a win unless all CPUs are pegged. - hugetlb_cgroup cleanups from Xiu Jianfeng in the series "mm/hugetlb_cgroup: rework on cftypes". - Miaohe Lin's series "Some cleanups for memory-failure" does just that thing. - Someone other than SeongJae has developed a DAMON feature in Honggyu Kim's series "DAMON based tiered memory management for CXL memory". This adds DAMON features which may be used to help determine the efficiency of our placement of CXL/PCIe attached DRAM. - DAMON user API centralization and simplificatio work in SeongJae Park's series "mm/damon: introduce DAMON parameters online commit function". - In the series "mm: page_type, zsmalloc and page_mapcount_reset()" David Hildenbrand does some maintenance work on zsmalloc - partially modernizing its use of pageframe fields. - Kefeng Wang provides more folio conversions in the series "mm: remove page_maybe_dma_pinned() and page_mkclean()". - More cleanup from David Hildenbrand, this time in the series "mm/memory_hotplug: use PageOffline() instead of PageReserved() for !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline() pages" and permits the removal of some virtio-mem hacks. - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and __folio_add_anon_rmap()" is a cleanup to the anon folio handling in preparation for mTHP (multisize THP) swapin. - Kefeng Wang's series "mm: improve clear and copy user folio" implements more folio conversions, this time in the area of large folio userspace copying. - The series "Docs/mm/damon/maintaier-profile: document a mailing tool and community meetup series" tells people how to get better involved with other DAMON developers. From SeongJae Park. - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does that. - David Hildenbrand sends along more cleanups, this time against the migration code. The series is "mm/migrate: move NUMA hinting fault folio isolation + checks under PTL". - Jan Kara has found quite a lot of strangenesses and minor errors in the readahead code. He addresses this in the series "mm: Fix various readahead quirks". - SeongJae Park's series "selftests/damon: test DAMOS tried regions and {min,max}_nr_regions" adds features and addresses errors in DAMON's self testing code. - Gavin Shan has found a userspace-triggerable WARN in the pagecache code. The series "mm/filemap: Limit page cache size to that supported by xarray" addresses this. The series is marked cc:stable. - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations and cleanup" cleans up and slightly optimizes KSM. - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of code motion. The series (which also makes the memcg-v1 code Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put under config option" and "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1" - Dan Schatzberg's series "Add swappiness argument to memory.reclaim" adds an additional feature to this cgroup-v2 control file. - The series "Userspace controls soft-offline pages" from Jiaqi Yan permits userspace to stop the kernel's automatic treatment of excessive correctable memory errors. In order to permit userspace to monitor and handle this situation. - Kefeng Wang's series "mm: migrate: support poison recover from migrate folio" teaches the kernel to appropriately handle migration from poisoned source folios rather than simply panicing. - SeongJae Park's series "Docs/damon: minor fixups and improvements" does those things. - In the series "mm/zsmalloc: change back to per-size_class lock" Chengming Zhou improves zsmalloc's scalability and memory utilization. - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare refcount increments. So these paes can first be moved aside if they reside in the movable zone or a CMA block. - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps for much faster reading of vma information. The series is "query VMAs from /proc/<pid>/maps". - In the series "mm: introduce per-order mTHP split counters" Lance Yang improves the kernel's presentation of developer information related to multisize THP splitting. - Michael Ellerman has developed the series "Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64)". This permits userspace to use all available huge page sizes. - In the series "revert unconditional slab and page allocator fault injection calls" Vlastimil Babka removes a performance-affecting and not very useful feature from slab fault injection. * tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits) mm/mglru: fix ineffective protection calculation mm/zswap: fix a white space issue mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio mm/hugetlb: fix possible recursive locking detected warning mm/gup: clear the LRU flag of a page before adding to LRU batch mm/numa_balancing: teach mpol_to_str about the balancing mode mm: memcg1: convert charge move flags to unsigned long long alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting lib: reuse page_ext_data() to obtain codetag_ref lib: add missing newline character in the warning message mm/mglru: fix overshooting shrinker memory mm/mglru: fix div-by-zero in vmpressure_calc_level() mm/kmemleak: replace strncpy() with strscpy() mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB mm: ignore data-race in __swap_writepage hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr mm: shmem: rename mTHP shmem counters mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async() mm/migrate: putback split folios when numa hint migration fails ...
2024-07-18Merge tag 'ftrace-v6.11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ftrace updates from Steven Rostedt: "Rewrite of function graph tracer to allow multiple users Up until now, the function graph tracer could only have a single user attached to it. If another user tried to attach to the function graph tracer while one was already attached, it would fail. Allowing function graph tracer to have more than one user has been asked for since 2009, but it required a rewrite to the logic to pull it off so it never happened. Until now! There's three systems that trace the return of a function. That is kretprobes, function graph tracer, and BPF. kretprobes and function graph tracing both do it similarly. The difference is that kretprobes uses a shadow stack per callback and function graph tracer creates a shadow stack for all tasks. The function graph tracer method makes it possible to trace the return of all functions. As kretprobes now needs that feature too, allowing it to use function graph tracer was needed. BPF also wants to trace the return of many probes and its method doesn't scale either. Having it use function graph tracer would improve that. By allowing function graph tracer to have multiple users allows both kretprobes and BPF to use function graph tracer in these cases. This will allow kretprobes code to be removed in the future as it's version will no longer be needed. Note, function graph tracer is only limited to 16 simultaneous users, due to shadow stack size and allocated slots" * tag 'ftrace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (49 commits) fgraph: Use str_plural() in test_graph_storage_single() function_graph: Add READ_ONCE() when accessing fgraph_array[] ftrace: Add missing kerneldoc parameters to unregister_ftrace_direct() function_graph: Everyone uses HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, remove it function_graph: Fix up ftrace_graph_ret_addr() function_graph: Make fgraph_update_pid_func() a stub for !DYNAMIC_FTRACE function_graph: Rename BYTE_NUMBER to CHAR_NUMBER in selftests fgraph: Remove some unused functions ftrace: Hide one more entry in stack trace when ftrace_pid is enabled function_graph: Do not update pid func if CONFIG_DYNAMIC_FTRACE not enabled function_graph: Make fgraph_do_direct static key static ftrace: Fix prototypes for ftrace_startup/shutdown_subops() ftrace: Assign RCU list variable with rcu_assign_ptr() ftrace: Assign ftrace_list_end to ftrace_ops_list type cast to RCU ftrace: Declare function_trace_op in header to quiet sparse warning ftrace: Add comments to ftrace_hash_move() and friends ftrace: Convert "inc" parameter to bool in ftrace_hash_rec_update_modify() ftrace: Add comments to ftrace_hash_rec_disable/enable() ftrace: Remove "filter_hash" parameter from __ftrace_hash_rec_update() ftrace: Rename dup_hash() and comment it ...
2024-07-16Merge tag 'net-next-6.11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Not much excitement - a handful of large patchsets (devmem among them) did not make it in time. Core & protocols: - Use local_lock in addition to local_bh_disable() to protect per-CPU resources in networking, a step closer for local_bh_disable() not to act as a big lock on PREEMPT_RT - Use flex array for netdevice priv area, ensure its cache alignment - Add a sysctl knob to allow user to specify a default rto_min at socket init time. Bit of a big hammer but multiple companies were independently carrying such patch downstream so clearly it's useful - Support scheduling transmission of packets based on CLOCK_TAI - Un-pin TCP TIMEWAIT timer to avoid it firing on CPUs later cordoned off using cpusets - Support multiple L2TPv3 UDP tunnels using the same 5-tuple address - Allow configuration of multipath hash seed, to both allow synchronizing hashing of two routers, and preventing partial accidental sync - Improve TCP compliance with RFC 9293 for simultaneous connect() - Support sending NAT keepalives in IPsec ESP in UDP states. Userspace IKE daemon had to do this before, but the kernel can better keep track of it - Support sending supervision HSR frames with MAC addresses stored in ProxyNodeTable when RedBox (i.e. HSR-SAN) is enabled - Introduce IPPROTO_SMC for selecting SMC when socket is created - Allow UDP GSO transmit from devices with no checksum offload - openvswitch: add packet sampling via psample, separating the sampled traffic from "upcall" packets sent to user space for forwarding - nf_tables: shrink memory consumption for transaction objects Things we sprinkled into general kernel code: - Power Sequencing subsystem (used by Qualcomm Bluetooth driver for QCA6390) [ Already merged separately - Linus ] - Add IRQ information in sysfs for auxiliary bus - Introduce guard definition for local_lock - Add aligned flavor of __cacheline_group_{begin, end}() markings for grouping fields in structures BPF: - Notify user space (via epoll) when a struct_ops object is getting detached/unregistered - Add new kfuncs for a generic, open-coded bits iterator - Enable BPF programs to declare arrays of kptr, bpf_rb_root, and bpf_list_head - Support resilient split BTF which cuts down on duplication and makes BTF as compact as possible WRT BTF from modules - Add support for dumping kfunc prototypes from BTF which enables both detecting as well as dumping compilable prototypes for kfuncs - riscv64 BPF JIT improvements in particular to add 12-argument support for BPF trampolines and to utilize bpf_prog_pack for the latter - Add the capability to offload the netfilter flowtable in XDP layer through kfuncs Driver API: - Allow users to configure IRQ tresholds between which automatic IRQ moderation can choose - Expand Power Sourcing (PoE) status with power, class and failure reason. Support setting power limits - Track additional RSS contexts in the core, make sure configuration changes don't break them - Support IPsec crypto offload for IPv6 ESP and IPv4 UDP-encapsulated ESP data paths - Support updating firmware on SFP modules Tests and tooling: - mptcp: use net/lib.sh to manage netns - TCP-AO and TCP-MD5: replace debug prints used by tests with tracepoints - openvswitch: make test self-contained (don't depend on OvS CLI tools) Drivers: - Ethernet high-speed NICs: - Broadcom (bnxt): - increase the max total outstanding PTP TX packets to 4 - add timestamping statistics support - implement netdev_queue_mgmt_ops - support new RSS context API - Intel (100G, ice, idpf): - implement FEC statistics and dumping signal quality indicators - support E825C products (with 56Gbps PHYs) - nVidia/Mellanox: - support HW-GRO - mlx4/mlx5: support per-queue statistics via netlink - obey the max number of EQs setting in sub-functions - AMD/Solarflare: - support new RSS context API - AMD/Pensando: - ionic: rework fix for doorbell miss to lower overhead and skip it on new HW - Wangxun: - txgbe: support Flow Director perfect filters - Ethernet NICs consumer, embedded and virtual: - Add driver for Tehuti Networks TN40xx chips - Add driver for Meta's internal NIC chips - Add driver for Ethernet MAC on Airoha EN7581 SoCs - Add driver for Renesas Ethernet-TSN devices - Google cloud vNIC: - flow steering support - Microsoft vNIC: - support page sizes other than 4KB on ARM64 - vmware vNIC: - support latency measurement (update to version 9) - VirtIO net: - support for Byte Queue Limits - support configuring thresholds for automatic IRQ moderation - support for AF_XDP Rx zero-copy - Synopsys (stmmac): - support for STM32MP13 SoC - let platforms select the right PCS implementation - TI: - icssg-prueth: add multicast filtering support - icssg-prueth: enable PTP timestamping and PPS - Renesas: - ravb: improve Rx performance 30-400% by using page pool, theaded NAPI and timer-based IRQ coalescing - ravb: add MII support for R-Car V4M - Cadence (macb): - macb: add ARP support to Wake-On-LAN - Cortina: - use phylib for RX and TX pause configuration - Ethernet switches: - nVidia/Mellanox: - support configuration of multipath hash seed - report more accurate max MTU - use page_pool to improve Rx performance - MediaTek: - mt7530: add support for bridge port isolation - Qualcomm: - qca8k: add support for bridge port isolation - Microchip: - lan9371/2: add 100BaseTX PHY support - NXP: - vsc73xx: implement VLAN operations - Ethernet PHYs: - aquantia: enable support for aqr115c - aquantia: add support for PHY LEDs - realtek: add support for rtl8224 2.5Gbps PHY - xpcs: add memory-mapped device support - add BroadR-Reach link mode and support in Broadcom's PHY driver - CAN: - add document for ISO 15765-2 protocol support - mcp251xfd: workaround for erratum DS80000789E, use timestamps to catch when device returns incorrect FIFO status - WiFi: - mac80211/cfg80211: - parse Transmit Power Envelope (TPE) data in mac80211 instead of in drivers - improvements for 6 GHz regulatory flexibility - multi-link improvements - support multiple radios per wiphy - remove DEAUTH_NEED_MGD_TX_PREP flag - Intel (iwlwifi): - bump FW API to 91 for BZ/SC devices - report 64-bit radiotap timestamp - enable P2P low latency by default - handle Transmit Power Envelope (TPE) advertised by AP - remove support for older FW for new devices - fast resume (keeping the device configured) - mvm: re-enable Multi-Link Operation (MLO) - aggregation (A-MSDU) optimizations - MediaTek (mt76): - mt7925 Multi-Link Operation (MLO) support - Qualcomm (ath10k): - LED support for various chipsets - Qualcomm (ath12k): - remove unsupported Tx monitor handling - support channel 2 in 6 GHz band - support Spatial Multiplexing Power Save (SMPS) in 6 GHz band - supprt multiple BSSID (MBSSID) and Enhanced Multi-BSSID Advertisements (EMA) - support dynamic VLAN - add panic handler for resetting the firmware state - DebugFS support for datapath statistics - WCN7850: support for Wake on WLAN - Microchip (wilc1000): - read MAC address during probe to make it visible to user space - suspend/resume improvements - TI (wl18xx): - support newer firmware versions - RealTek (rtw89): - preparation for RTL8852BE-VT support - Wake on WLAN support for WiFi 6 chips - 36-bit PCI DMA support - RealTek (rtlwifi): - RTL8192DU support - Broadcom (brcmfmac): - Management Frame Protection support (to enable WPA3) - Bluetooth: - qualcomm: use the power sequencer for QCA6390 - btusb: mediatek: add ISO data transmission functions - hci_bcm4377: add BCM4388 support - btintel: add support for BlazarU core - btintel: add support for Whale Peak2 - btnxpuart: add support for AW693 A1 chipset - btnxpuart: add support for IW615 chipset - btusb: add Realtek RTL8852BE support ID 0x13d3:0x3591" * tag 'net-next-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1589 commits) eth: fbnic: Fix spelling mistake "tiggerring" -> "triggering" tcp: Replace strncpy() with strscpy() wifi: ath12k: fix build vs old compiler tcp: Don't access uninit tcp_rsk(req)->ao_keyid in tcp_create_openreq_child(). eth: fbnic: Write the TCAM tables used for RSS control and Rx to host eth: fbnic: Add L2 address programming eth: fbnic: Add basic Rx handling eth: fbnic: Add basic Tx handling eth: fbnic: Add link detection eth: fbnic: Add initial messaging to notify FW of our presence eth: fbnic: Implement Rx queue alloc/start/stop/free eth: fbnic: Implement Tx queue alloc/start/stop/free eth: fbnic: Allocate a netdevice and napi vectors with queues eth: fbnic: Add FW communication mechanism eth: fbnic: Add message parsing for FW messages eth: fbnic: Add register init to set PCIe/Ethernet device config eth: fbnic: Allocate core device specific structures and devlink interface eth: fbnic: Add scaffolding for Meta's NIC driver PCI: Add Meta Platforms vendor ID net/sched: cls_flower: propagate tca[TCA_OPTIONS] to NL_REQ_ATTR_CHECK ...
2024-07-16Merge tag 'perf-core-2024-07-16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull performance events updates from Ingo Molnar: - Intel PT support enhancements & fixes - Fix leaked SIGTRAP events - Improve and fix the Intel uncore driver - Add support for Intel HBM and CXL uncore counters - Add Intel Lake and Arrow Lake support - AMD uncore driver fixes - Make SIGTRAP and __perf_pending_irq() work on RT - Micro-optimizations - Misc cleanups and fixes * tag 'perf-core-2024-07-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits) perf/x86/intel: Add a distinct name for Granite Rapids perf/x86/intel/ds: Fix non 0 retire latency on Raptorlake perf/x86/intel: Hide Topdown metrics events if the feature is not enumerated perf/x86/intel/uncore: Fix the bits of the CHA extended umask for SPR perf: Split __perf_pending_irq() out of perf_pending_irq() perf: Don't disable preemption in perf_pending_task(). perf: Move swevent_htable::recursion into task_struct. perf: Shrink the size of the recursion counter. perf: Enqueue SIGTRAP always via task_work. task_work: Add TWA_NMI_CURRENT as an additional notify mode. perf: Move irq_work_queue() where the event is prepared. perf: Fix event leak upon exec and file release perf: Fix event leak upon exit task_work: Introduce task_work_cancel() again task_work: s/task_work_cancel()/task_work_cancel_func()/ perf/x86/amd/uncore: Fix DF and UMC domain identification perf/x86/amd/uncore: Avoid PMU registration if counters are unavailable perf/x86/intel: Support Perfmon MSRs aliasing perf/x86/intel: Support PERFEVTSEL extension perf/x86: Add config_mask to represent EVENTSEL bitmask ...
2024-07-16Merge tag 'sched-core-2024-07-16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Update Daniel Bristot de Oliveira's entry in MAINTAINERS, and credit him in CREDITS - Harmonize the lock-yielding behavior on dynamically selected preemption models with static ones - Reorganize the code a bit: split out sched/syscalls.c to reduce the size of sched/core.c - Micro-optimize psi_group_change() - Fix set_load_weight() for SCHED_IDLE tasks - Misc cleanups & fixes * tag 'sched-core-2024-07-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Update MAINTAINERS and CREDITS sched/fair: set_load_weight() must also call reweight_task() for SCHED_IDLE tasks sched/psi: Optimise psi_group_change a bit sched/core: Drop spinlocks on contention iff kernel is preemptible sched/core: Move preempt_model_*() helpers from sched.h to preempt.h sched/balance: Skip unnecessary updates to idle load balancer's flags idle: Remove stale RCU comment sched/headers: Move struct pre-declarations to the beginning of the header sched/core: Clean up kernel/sched/sched.h a bit sched/core: Simplify prefetch_curr_exec_start() sched: Fix spelling in comments sched/syscalls: Split out kernel/sched/syscalls.c from kernel/sched/core.c
2024-07-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: net/sched/act_ct.c 26488172b029 ("net/sched: Fix UAF when resolving a clash") 3abbd7ed8b76 ("act_ct: prepare for stolen verdict coming from conntrack and nat engine") No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-10mm: remove CONFIG_MEMCG_KMEMJohannes Weiner
CONFIG_MEMCG_KMEM used to be a user-visible option for whether slab tracking is enabled. It has been default-enabled and equivalent to CONFIG_MEMCG for almost a decade. We've only grown more kernel memory accounting sites since, and there is no imaginable cgroup usecase going forward that wants to track user pages but not the multitude of user-drivable kernel allocations. Link: https://lkml.kernel.org/r/20240701153148.452230-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: David Hildenbrand <david@redhat.com> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-09sched.h: always_inline alloc_tag_{save|restore} to fix modpost warningsSuren Baghdasaryan
Mark alloc_tag_{save|restore} as always_inline to fix the following modpost warnings: WARNING: modpost: vmlinux: section mismatch in reference: alloc_tag_save+0x1c (section: .text.unlikely) -> initcall_level_names (section: .init.data) WARNING: modpost: vmlinux: section mismatch in reference: alloc_tag_restore+0x3c (section: .text.unlikely) -> initcall_level_names (section: .init.data) The warnings happen when these functions are called from an __init function and they don't get inlined (remain in the .text section) while the value returned by get_current() points into .init.data section. Assuming get_current() always returns a valid address, this situation can happen only during init stage and accessing .init.data from .text section during that stage should pose no issues. Link: https://lkml.kernel.org/r/20240704132506.1011978-1-surenb@google.com Fixes: 22d407b164ff ("lib: add allocation tagging support for memory allocation profiling") Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202407032306.gi9nZsBi-lkp@intel.com/ Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Chris Zankel <chris@zankel.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-09perf: Move swevent_htable::recursion into task_struct.Sebastian Andrzej Siewior
The swevent_htable::recursion counter is used to avoid creating an swevent while an event is processed to avoid recursion. The counter is per-CPU and preemption must be disabled to have a stable counter. perf_pending_task() disables preemption to access the counter and then signal. This is problematic on PREEMPT_RT because sending a signal uses a spinlock_t which must not be acquired in atomic on PREEMPT_RT because it becomes a sleeping lock. The atomic context can be avoided by moving the counter into the task_struct. There is a 4 byte hole between futex_state (usually always on) and the following perf pointer (perf_event_ctxp). After the recursion lost some weight it fits perfectly. Move swevent_htable::recursion into task_struct. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Marco Elver <elver@google.com> Link: https://lore.kernel.org/r/20240704170424.1466941-6-bigeasy@linutronix.de
2024-07-04mm: memcg: put struct task_struct::in_user_fault under CONFIG_MEMCG_V1Roman Gushchin
The struct task_struct's in_user_fault member is not used by the cgroup v2's memory controller, so it can be put under the CONFIG_MEMCG_V1 config option. To do so, mem_cgroup_enter_user_fault() and mem_cgroup_exit_user_fault() are moved under the CONFIG_MEMCG_V1 option as well. Link: https://lkml.kernel.org/r/20240628210317.272856-10-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04mm: memcg: put struct task_struct::memcg_in_oom under CONFIG_MEMCG_V1Roman Gushchin
The memcg_in_oom field of the struct task_struct is not used by the cgroup v2's memory controller, so it can be happily compiled out if CONFIG_MEMCG_V1 is not set. Link: https://lkml.kernel.org/r/20240628210317.272856-9-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24sched: drop sched.h dependency on cpumaskYury Norov
sched.h needs cpumask.h mostly for types declaration. Now that we have cpumask_types.h, which is a significantly smaller header, we can rely on it. The only exception is UP stub for set_cpus_allowed_ptr(). The function needs to test bit #0 in a @new_mask, which can be trivially opencoded. Link: https://lkml.kernel.org/r/20240528005648.182376-5-yury.norov@gmail.com Signed-off-by: Yury Norov <yury.norov@gmail.com> Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com> Cc: Anna-Maria Behnsen <anna-maria@linutronix.de> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Dennis Zhou <dennis@kernel.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Yury Norov <yury.norov@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24sched: avoid using ilog2() in sched.hYury Norov
<linux/sched.h> indirectly via cpumask.h path includes the ilog2.h header to calculate ilog2(TASK_REPORT_MAX). The following patches drops sched.h dependency on cpumask.h, and to have a successful build, the header has to be included explicitly. sched.h is a frequently included header, and it's better to keep the dependency list as small as possible. So, instead of including ilog2.h for a single BUILD_BUG_ON() check, the same check may be implemented by taking exponent of the other part of equation. Link: https://lkml.kernel.org/r/20240528005648.182376-3-yury.norov@gmail.com Signed-off-by: Yury Norov <yury.norov@gmail.com> Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com> Cc: Anna-Maria Behnsen <anna-maria@linutronix.de> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Dennis Zhou <dennis@kernel.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Yury Norov <yury.norov@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.Sebastian Andrzej Siewior
The XDP redirect process is two staged: - bpf_prog_run_xdp() is invoked to run a eBPF program which inspects the packet and makes decisions. While doing that, the per-CPU variable bpf_redirect_info is used. - Afterwards xdp_do_redirect() is invoked and accesses bpf_redirect_info and it may also access other per-CPU variables like xskmap_flush_list. At the very end of the NAPI callback, xdp_do_flush() is invoked which does not access bpf_redirect_info but will touch the individual per-CPU lists. The per-CPU variables are only used in the NAPI callback hence disabling bottom halves is the only protection mechanism. Users from preemptible context (like cpu_map_kthread_run()) explicitly disable bottom halves for protections reasons. Without locking in local_bh_disable() on PREEMPT_RT this data structure requires explicit locking. PREEMPT_RT has forced-threaded interrupts enabled and every NAPI-callback runs in a thread. If each thread has its own data structure then locking can be avoided. Create a struct bpf_net_context which contains struct bpf_redirect_info. Define the variable on stack, use bpf_net_ctx_set() to save a pointer to it, bpf_net_ctx_clear() removes it again. The bpf_net_ctx_set() may nest. For instance a function can be used from within NET_RX_SOFTIRQ/ net_rx_action which uses bpf_net_ctx_set() and NET_TX_SOFTIRQ which does not. Therefore only the first invocations updates the pointer. Use bpf_net_ctx_get_ri() as a wrapper to retrieve the current struct bpf_redirect_info. The returned data structure is zero initialized to ensure nothing is leaked from stack. This is done on first usage of the struct. bpf_net_ctx_set() sets bpf_redirect_info::kern_flags to 0 to note that initialisation is required. First invocation of bpf_net_ctx_get_ri() will memset() the data structure and update bpf_redirect_info::kern_flags. bpf_redirect_info::nh is excluded from memset because it is only used once BPF_F_NEIGH is set which also sets the nh member. The kern_flags is moved past nh to exclude it from memset. The pointer to bpf_net_context is saved task's task_struct. Using always the bpf_net_context approach has the advantage that there is almost zero differences between PREEMPT_RT and non-PREEMPT_RT builds. Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Eduard Zingerman <eddyz87@gmail.com> Cc: Hao Luo <haoluo@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Song Liu <song@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Cc: Yonghong Song <yonghong.song@linux.dev> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20240620132727.660738-15-bigeasy@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-24net: softnet_data: Make xmit per task.Sebastian Andrzej Siewior
Softirq is preemptible on PREEMPT_RT. Without a per-CPU lock in local_bh_disable() there is no guarantee that only one device is transmitting at a time. With preemption and multiple senders it is possible that the per-CPU `recursion' counter gets incremented by different threads and exceeds XMIT_RECURSION_LIMIT leading to a false positive recursion alert. The `more' member is subject to similar problems if set by one thread for one driver and wrongly used by another driver within another thread. Instead of adding a lock to protect the per-CPU variable it is simpler to make xmit per-task. Sending and receiving skbs happens always in thread context anyway. Having a lock to protected the per-CPU counter would block/ serialize two sending threads needlessly. It would also require a recursive lock to ensure that the owner can increment the counter further. Make the softnet_data.xmit a task_struct member on PREEMPT_RT. Add needed wrapper. Cc: Ben Segall <bsegall@google.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20240620132727.660738-9-bigeasy@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-18sched_ext: Implement BPF extensible scheduler classTejun Heo
Implement a new scheduler class sched_ext (SCX), which allows scheduling policies to be implemented as BPF programs to achieve the following: 1. Ease of experimentation and exploration: Enabling rapid iteration of new scheduling policies. 2. Customization: Building application-specific schedulers which implement policies that are not applicable to general-purpose schedulers. 3. Rapid scheduler deployments: Non-disruptive swap outs of scheduling policies in production environments. sched_ext leverages BPF’s struct_ops feature to define a structure which exports function callbacks and flags to BPF programs that wish to implement scheduling policies. The struct_ops structure exported by sched_ext is struct sched_ext_ops, and is conceptually similar to struct sched_class. The role of sched_ext is to map the complex sched_class callbacks to the more simple and ergonomic struct sched_ext_ops callbacks. For more detailed discussion on the motivations and overview, please refer to the cover letter. Later patches will also add several example schedulers and documentation. This patch implements the minimum core framework to enable implementation of BPF schedulers. Subsequent patches will gradually add functionalities including safety guarantee mechanisms, nohz and cgroup support. include/linux/sched/ext.h defines struct sched_ext_ops. With the comment on top, each operation should be self-explanatory. The followings are worth noting: - Both "sched_ext" and its shorthand "scx" are used. If the identifier already has "sched" in it, "ext" is used; otherwise, "scx". - In sched_ext_ops, only .name is mandatory. Every operation is optional and if omitted a simple but functional default behavior is provided. - A new policy constant SCHED_EXT is added and a task can select sched_ext by invoking sched_setscheduler(2) with the new policy constant. However, if the BPF scheduler is not loaded, SCHED_EXT is the same as SCHED_NORMAL and the task is scheduled by CFS. When the BPF scheduler is loaded, all tasks which have the SCHED_EXT policy are switched to sched_ext. - To bridge the workflow imbalance between the scheduler core and sched_ext_ops callbacks, sched_ext uses simple FIFOs called dispatch queues (dsq's). By default, there is one global dsq (SCX_DSQ_GLOBAL), and one local per-CPU dsq (SCX_DSQ_LOCAL). SCX_DSQ_GLOBAL is provided for convenience and need not be used by a scheduler that doesn't require it. SCX_DSQ_LOCAL is the per-CPU FIFO that sched_ext pulls from when putting the next task on the CPU. The BPF scheduler can manage an arbitrary number of dsq's using scx_bpf_create_dsq() and scx_bpf_destroy_dsq(). - sched_ext guarantees system integrity no matter what the BPF scheduler does. To enable this, each task's ownership is tracked through p->scx.ops_state and all tasks are put on scx_tasks list. The disable path can always recover and revert all tasks back to CFS. See p->scx.ops_state and scx_tasks. - A task is not tied to its rq while enqueued. This decouples CPU selection from queueing and allows sharing a scheduling queue across an arbitrary subset of CPUs. This adds some complexities as a task may need to be bounced between rq's right before it starts executing. See dispatch_to_local_dsq() and move_task_to_local_dsq(). - One complication that arises from the above weak association between task and rq is that synchronizing with dequeue() gets complicated as dequeue() may happen anytime while the task is enqueued and the dispatch path might need to release the rq lock to transfer the task. Solving this requires a bit of complexity. See the logic around p->scx.sticky_cpu and p->scx.ops_qseq. - Both enable and disable paths are a bit complicated. The enable path switches all tasks without blocking to avoid issues which can arise from partially switched states (e.g. the switching task itself being starved). The disable path can't trust the BPF scheduler at all, so it also has to guarantee forward progress without blocking. See scx_ops_enable() and scx_ops_disable_workfn(). - When sched_ext is disabled, static_branches are used to shut down the entry points from hot paths. v7: - scx_ops_bypass() was incorrectly and unnecessarily trying to grab scx_ops_enable_mutex which can lead to deadlocks in the disable path. Fixed. - Fixed TASK_DEAD handling bug in scx_ops_enable() path which could lead to use-after-free. - Consolidated per-cpu variable usages and other cleanups. v6: - SCX_NR_ONLINE_OPS replaced with SCX_OPI_*_BEGIN/END so that multiple groups can be expressed. Later CPU hotplug operations are put into their own group. - SCX_OPS_DISABLING state is replaced with the new bypass mechanism which allows temporarily putting the system into simple FIFO scheduling mode bypassing the BPF scheduler. In addition to the shut down path, this will also be used to isolate the BPF scheduler across PM events. Enabling and disabling the bypass mode requires iterating all runnable tasks. rq->scx.runnable_list addition is moved from the later watchdog patch. - ops.prep_enable() is replaced with ops.init_task() and ops.enable/disable() are now called whenever the task enters and leaves sched_ext instead of when the task becomes schedulable on sched_ext and stops being so. A new operation - ops.exit_task() - is called when the task stops being schedulable on sched_ext. - scx_bpf_dispatch() can now be called from ops.select_cpu() too. This removes the need for communicating local dispatch decision made by ops.select_cpu() to ops.enqueue() via per-task storage. SCX_KF_SELECT_CPU is added to support the change. - SCX_TASK_ENQ_LOCAL which told the BPF scheudler that scx_select_cpu_dfl() wants the task to be dispatched to the local DSQ was removed. Instead, scx_bpf_select_cpu_dfl() now dispatches directly if it finds a suitable idle CPU. If such behavior is not desired, users can use scx_bpf_select_cpu_dfl() which returns the verdict in a bool out param. - scx_select_cpu_dfl() was mishandling WAKE_SYNC and could end up queueing many tasks on a local DSQ which makes tasks to execute in order while other CPUs stay idle which made some hackbench numbers really bad. Fixed. - The current state of sched_ext can now be monitored through files under /sys/sched_ext instead of /sys/kernel/debug/sched/ext. This is to enable monitoring on kernels which don't enable debugfs. - sched_ext wasn't telling BPF that ops.dispatch()'s @prev argument may be NULL and a BPF scheduler which derefs the pointer without checking could crash the kernel. Tell BPF. This is currently a bit ugly. A better way to annotate this is expected in the future. - scx_exit_info updated to carry pointers to message buffers instead of embedding them directly. This decouples buffer sizes from API so that they can be changed without breaking compatibility. - exit_code added to scx_exit_info. This is used to indicate different exit conditions on non-error exits and will be used to handle e.g. CPU hotplugs. - The patch "sched_ext: Allow BPF schedulers to switch all eligible tasks into sched_ext" is folded in and the interface is changed so that partial switching is indicated with a new ops flag %SCX_OPS_SWITCH_PARTIAL. This makes scx_bpf_switch_all() unnecessasry and in turn SCX_KF_INIT. ops.init() is now called with SCX_KF_SLEEPABLE. - Code reorganized so that only the parts necessary to integrate with the rest of the kernel are in the header files. - Changes to reflect the BPF and other kernel changes including the addition of bpf_sched_ext_ops.cfi_stubs. v5: - To accommodate 32bit configs, p->scx.ops_state is now atomic_long_t instead of atomic64_t and scx_dsp_buf_ent.qseq which uses load_acquire/store_release is now unsigned long instead of u64. - Fix the bug where bpf_scx_btf_struct_access() was allowing write access to arbitrary fields. - Distinguish kfuncs which can be called from any sched_ext ops and from anywhere. e.g. scx_bpf_pick_idle_cpu() can now be called only from sched_ext ops. - Rename "type" to "kind" in scx_exit_info to make it easier to use on languages in which "type" is a reserved keyword. - Since cff9b2332ab7 ("kernel/sched: Modify initial boot task idle setup"), PF_IDLE is not set on idle tasks which haven't been online yet which made scx_task_iter_next_filtered() include those idle tasks in iterations leading to oopses. Update scx_task_iter_next_filtered() to directly test p->sched_class against idle_sched_class instead of using is_idle_task() which tests PF_IDLE. - Other updates to match upstream changes such as adding const to set_cpumask() param and renaming check_preempt_curr() to wakeup_preempt(). v4: - SCHED_CHANGE_BLOCK replaced with the previous sched_deq_and_put_task()/sched_enq_and_set_tsak() pair. This is because upstream is adaopting a different generic cleanup mechanism. Once that lands, the code will be adapted accordingly. - task_on_scx() used to test whether a task should be switched into SCX, which is confusing. Renamed to task_should_scx(). task_on_scx() now tests whether a task is currently on SCX. - scx_has_idle_cpus is barely used anymore and replaced with direct check on the idle cpumask. - SCX_PICK_IDLE_CORE added and scx_pick_idle_cpu() improved to prefer fully idle cores. - ops.enable() now sees up-to-date p->scx.weight value. - ttwu_queue path is disabled for tasks on SCX to avoid confusing BPF schedulers expecting ->select_cpu() call. - Use cpu_smt_mask() instead of topology_sibling_cpumask() like the rest of the scheduler. v3: - ops.set_weight() added to allow BPF schedulers to track weight changes without polling p->scx.weight. - move_task_to_local_dsq() was losing SCX-specific enq_flags when enqueueing the task on the target dsq because it goes through activate_task() which loses the upper 32bit of the flags. Carry the flags through rq->scx.extra_enq_flags. - scx_bpf_dispatch(), scx_bpf_pick_idle_cpu(), scx_bpf_task_running() and scx_bpf_task_cpu() now use the new KF_RCU instead of KF_TRUSTED_ARGS to make it easier for BPF schedulers to call them. - The kfunc helper access control mechanism implemented through sched_ext_entity.kf_mask is improved. Now SCX_CALL_OP*() is always used when invoking scx_ops operations. v2: - balance_scx_on_up() is dropped. Instead, on UP, balance_scx() is called from put_prev_taks_scx() and pick_next_task_scx() as necessary. To determine whether balance_scx() should be called from put_prev_task_scx(), SCX_TASK_DEQD_FOR_SLEEP flag is added. See the comment in put_prev_task_scx() for details. - sched_deq_and_put_task() / sched_enq_and_set_task() sequences replaced with SCHED_CHANGE_BLOCK(). - Unused all_dsqs list removed. This was a left-over from previous iterations. - p->scx.kf_mask is added to track and enforce which kfunc helpers are allowed. Also, init/exit sequences are updated to make some kfuncs always safe to call regardless of the current BPF scheduler state. Combined, this should make all the kfuncs safe. - BPF now supports sleepable struct_ops operations. Hacky workaround removed and operations and kfunc helpers are tagged appropriately. - BPF now supports bitmask / cpumask helpers. scx_bpf_get_idle_cpumask() and friends are added so that BPF schedulers can use the idle masks with the generic helpers. This replaces the hacky kfunc helpers added by a separate patch in V1. - CONFIG_SCHED_CLASS_EXT can no longer be enabled if SCHED_CORE is enabled. This restriction will be removed by a later patch which adds core-sched support. - Add MAINTAINERS entries and other misc changes. Signed-off-by: Tejun Heo <tj@kernel.org> Co-authored-by: David Vernet <dvernet@meta.com> Acked-by: Josh Don <joshdon@google.com> Acked-by: Hao Luo <haoluo@google.com> Acked-by: Barret Rhoden <brho@google.com> Cc: Andrea Righi <andrea.righi@canonical.com>
2024-06-05sched/core: Move preempt_model_*() helpers from sched.h to preempt.hSean Christopherson
Move the declarations and inlined implementations of the preempt_model_*() helpers to preempt.h so that they can be referenced in spinlock.h without creating a potential circular dependency between spinlock.h and sched.h. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ankur Arora <ankur.a.arora@oracle.com> Link: https://lkml.kernel.org/r/20240528003521.979836-2-ankur.a.arora@oracle.com
2024-06-04function_graph: Convert ret_stack to a series of longsSteven Rostedt (VMware)
In order to make it possible to have multiple callbacks registered with the function_graph tracer, the retstack needs to be converted from an array of ftrace_ret_stack structures to an array of longs. This will allow to store the list of callbacks on the stack for the return side of the functions. Link: https://lore.kernel.org/linux-trace-kernel/171509092742.162236.4427737821399314856.stgit@devnote2 Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.073111754@goodmis.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Guo Ren <guoren@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-19Merge tag 'mm-stable-2024-05-17-19-19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
2024-05-11memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_orderXiu Jianfeng
Since commit 857f21397f71 ("memcg, oom: remove unnecessary check in mem_cgroup_oom_synchronize()"), memcg_oom_gfp_mask and memcg_oom_order are no longer used any more. Link: https://lkml.kernel.org/r/20240509032628.1217652-1-xiujianfeng@huawei.com Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Benjamin Segall <bsegall@google.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25lib: add allocation tagging support for memory allocation profilingSuren Baghdasaryan
Introduce CONFIG_MEM_ALLOC_PROFILING which provides definitions to easily instrument memory allocators. It registers an "alloc_tags" codetag type with /proc/allocinfo interface to output allocation tag information when the feature is enabled. CONFIG_MEM_ALLOC_PROFILING_DEBUG is provided for debugging the memory allocation profiling instrumentation. Memory allocation profiling can be enabled or disabled at runtime using /proc/sys/vm/mem_profiling sysctl when CONFIG_MEM_ALLOC_PROFILING_DEBUG=n. CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT enables memory allocation profiling by default. [surenb@google.com: Documentation/filesystems/proc.rst: fix allocinfo title] Link: https://lkml.kernel.org/r/20240326073813.727090-1-surenb@google.com [surenb@google.com: do limited memory accounting for modules with ARCH_NEEDS_WEAK_PER_CPU] Link: https://lkml.kernel.org/r/20240402180933.1663992-2-surenb@google.com [klarasmodin@gmail.com: explicitly include irqflags.h in alloc_tag.h] Link: https://lkml.kernel.org/r/20240407133252.173636-1-klarasmodin@gmail.com [surenb@google.com: fix alloc_tag_init() to prevent passing NULL to PTR_ERR()] Link: https://lkml.kernel.org/r/20240417003349.2520094-1-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-14-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Klara Modin <klarasmodin@gmail.com> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-25sched/fair: Check if a task has a fitting CPU when updating misfitQais Yousef
If a misfit task is affined to a subset of the possible CPUs, we need to verify that one of these CPUs can fit it. Otherwise the load balancer code will continuously trigger needlessly leading the balance_interval to increase in return and eventually end up with a situation where real imbalances take a long time to address because of this impossible imbalance situation. This can happen in Android world where it's common for background tasks to be restricted to little cores. Similarly if we can't fit the biggest core, triggering misfit is pointless as it is the best we can ever get on this system. To be able to detect that; we use asym_cap_list to iterate through capacities in the system to see if the task is able to run at a higher capacity level based on its p->cpus_ptr. We do that when the affinity change, a fair task is forked, or when a task switched to fair policy. We store the max_allowed_capacity in task_struct to allow for cheap comparison in the fast path. Improve check_misfit_status() function by removing redundant checks. misfit_task_load will be 0 if the task can't move to a bigger CPU. And nohz_balancer_kick() already checks for cpu_check_capacity() before calling check_misfit_status(). Test: ===== Add trace_printk("balance_interval = %lu\n", interval) in get_sd_balance_interval(). run if [ "$MASK" != "0" ]; then adb shell "taskset -a $MASK cat /dev/zero > /dev/null" fi sleep 10 // parse ftrace buffer counting the occurrence of each valaue Where MASK is either: * 0: no busy task running * 1: busy task is pinned to 1 cpu; handled today to not cause misfit * f: busy task pinned to little cores, simulates busy background task, demonstrates the problem to be fixed Results: ======== Note how occurrence of balance_interval = 128 overshoots for MASK = f. BEFORE ------ MASK=0 1 balance_interval = 175 120 balance_interval = 128 846 balance_interval = 64 55 balance_interval = 63 215 balance_interval = 32 2 balance_interval = 31 2 balance_interval = 16 4 balance_interval = 8 1870 balance_interval = 4 65 balance_interval = 2 MASK=1 27 balance_interval = 175 37 balance_interval = 127 840 balance_interval = 64 167 balance_interval = 63 449 balance_interval = 32 84 balance_interval = 31 304 balance_interval = 16 1156 balance_interval = 8 2781 balance_interval = 4 428 balance_interval = 2 MASK=f 1 balance_interval = 175 1328 balance_interval = 128 44 balance_interval = 64 101 balance_interval = 63 25 balance_interval = 32 5 balance_interval = 31 23 balance_interval = 16 23 balance_interval = 8 4306 balance_interval = 4 177 balance_interval = 2 AFTER ----- Note how the high values almost disappear for all MASK values. The system has background tasks that could trigger the problem without simulate it even with MASK=0. MASK=0 103 balance_interval = 63 19 balance_interval = 31 194 balance_interval = 8 4827 balance_interval = 4 179 balance_interval = 2 MASK=1 131 balance_interval = 63 1 balance_interval = 31 87 balance_interval = 8 3600 balance_interval = 4 7 balance_interval = 2 MASK=f 8 balance_interval = 127 182 balance_interval = 63 3 balance_interval = 31 9 balance_interval = 16 415 balance_interval = 8 3415 balance_interval = 4 21 balance_interval = 2 Signed-off-by: Qais Yousef <qyousef@layalina.io> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20240324004552.999936-3-qyousef@layalina.io
2024-03-25Merge tag 'v6.9-rc1' into sched/core, to pick up fixes and to refresh the branchIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-03-15Merge tag 'bcachefs-2024-03-13' of https://evilpiepirate.org/git/bcachefsLinus Torvalds
Pull bcachefs updates from Kent Overstreet: - Subvolume children btree; this is needed for providing a userspace interface for walking subvolumes, which will come later - Lots of improvements to directory structure checking - Improved journal pipelining, significantly improving performance on high iodepth write workloads - Discard path improvements: the discard path is more efficient, and no longer flushes the journal unnecessarily - Buffered write path can now avoid taking the inode lock - new mm helper: memalloc_flags_{save|restore} - mempool now does kvmalloc mempools * tag 'bcachefs-2024-03-13' of https://evilpiepirate.org/git/bcachefs: (128 commits) bcachefs: time_stats: shrink time_stat_buffer for better alignment bcachefs: time_stats: split stats-with-quantiles into a separate structure bcachefs: mean_and_variance: put struct mean_and_variance_weighted on a diet bcachefs: time_stats: add larger units bcachefs: pull out time_stats.[ch] bcachefs: reconstruct_alloc cleanup bcachefs: fix bch_folio_sector padding bcachefs: Fix btree key cache coherency during replay bcachefs: Always flush write buffer in delete_dead_inodes() bcachefs: Fix order of gc_done passes bcachefs: fix deletion of indirect extents in btree_gc bcachefs: Prefer struct_size over open coded arithmetic bcachefs: Kill unused flags argument to btree_split() bcachefs: Check for writing superblocks with nonsense member seq fields bcachefs: fix bch2_journal_buf_to_text() lib/generic-radix-tree.c: Make nodes more reasonably sized bcachefs: copy_(to|from)_user_errcode() bcachefs: Split out bkey_types.h bcachefs: fix lost journal buf wakeup due to improved pipelining bcachefs: intercept mountoption value for bool type ...
2024-03-14Merge tag 'mm-stable-2024-03-13-20-04' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames from hotplugged memory rather than only from main memory. Series "implement "memmap on memory" feature on s390". - More folio conversions from Matthew Wilcox in the series "Convert memcontrol charge moving to use folios" "mm: convert mm counter to take a folio" - Chengming Zhou has optimized zswap's rbtree locking, providing significant reductions in system time and modest but measurable reductions in overall runtimes. The series is "mm/zswap: optimize the scalability of zswap rb-tree". - Chengming Zhou has also provided the series "mm/zswap: optimize zswap lru list" which provides measurable runtime benefits in some swap-intensive situations. - And Chengming Zhou further optimizes zswap in the series "mm/zswap: optimize for dynamic zswap_pools". Measured improvements are modest. - zswap cleanups and simplifications from Yosry Ahmed in the series "mm: zswap: simplify zswap_swapoff()". - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has contributed several DAX cleanups as well as adding a sysfs tunable to control the memmap_on_memory setting when the dax device is hotplugged as system memory. - Johannes Weiner has added the large series "mm: zswap: cleanups", which does that. - More DAMON work from SeongJae Park in the series "mm/damon: make DAMON debugfs interface deprecation unignorable" "selftests/damon: add more tests for core functionalities and corner cases" "Docs/mm/damon: misc readability improvements" "mm/damon: let DAMOS feeds and tame/auto-tune itself" - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs extension" Rakie Kim has developed a new mempolicy interleaving policy wherein we allocate memory across nodes in a weighted fashion rather than uniformly. This is beneficial in heterogeneous memory environments appearing with CXL. - Christophe Leroy has contributed some cleanup and consolidation work against the ARM pagetable dumping code in the series "mm: ptdump: Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute". - Luis Chamberlain has added some additional xarray selftesting in the series "test_xarray: advanced API multi-index tests". - Muhammad Usama Anjum has reworked the selftest code to make its human-readable output conform to the TAP ("Test Anything Protocol") format. Amongst other things, this opens up the use of third-party tools to parse and process out selftesting results. - Ryan Roberts has added fork()-time PTE batching of THP ptes in the series "mm/memory: optimize fork() with PTE-mapped THP". Mainly targeted at arm64, this significantly speeds up fork() when the process has a large number of pte-mapped folios. - David Hildenbrand also gets in on the THP pte batching game in his series "mm/memory: optimize unmap/zap with PTE-mapped THP". It implements batching during munmap() and other pte teardown situations. The microbenchmark improvements are nice. - And in the series "Transparent Contiguous PTEs for User Mappings" Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte mappings"). Kernel build times on arm64 improved nicely. Ryan's series "Address some contpte nits" provides some followup work. - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has fixed an obscure hugetlb race which was causing unnecessary page faults. He has also added a reproducer under the selftest code. - In the series "selftests/mm: Output cleanups for the compaction test", Mark Brown did what the title claims. - Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring". - Even more zswap material from Nhat Pham. The series "fix and extend zswap kselftests" does as claimed. - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in our handling of DAX on archiecctures which have virtually aliasing data caches. The arm architecture is the main beneficiary. - Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic improvements in worst-case mmap_lock hold times during certain userfaultfd operations. - Some page_owner enhancements and maintenance work from Oscar Salvador in his series "page_owner: print stacks and their outstanding allocations" "page_owner: Fixup and cleanup" - Uladzislau Rezki has contributed some vmalloc scalability improvements in his series "Mitigate a vmap lock contention". It realizes a 12x improvement for a certain microbenchmark. - Some kexec/crash cleanup work from Baoquan He in the series "Split crash out from kexec and clean up related config items". - Some zsmalloc maintenance work from Chengming Zhou in the series "mm/zsmalloc: fix and optimize objects/page migration" "mm/zsmalloc: some cleanup for get/set_zspage_mapping()" - Zi Yan has taught the MM to perform compaction on folios larger than order=0. This a step along the path to implementaton of the merging of large anonymous folios. The series is named "Enable >0 order folio memory compaction". - Christoph Hellwig has done quite a lot of cleanup work in the pagecache writeback code in his series "convert write_cache_pages() to an iterator". - Some modest hugetlb cleanups and speedups in Vishal Moola's series "Handle hugetlb faults under the VMA lock". - Zi Yan has changed the page splitting code so we can split huge pages into sizes other than order-0 to better utilize large folios. The series is named "Split a folio to any lower order folios". - David Hildenbrand has contributed the series "mm: remove total_mapcount()", a cleanup. - Matthew Wilcox has sought to improve the performance of bulk memory freeing in his series "Rearrange batched folio freeing". - Gang Li's series "hugetlb: parallelize hugetlb page init on boot" provides large improvements in bootup times on large machines which are configured to use large numbers of hugetlb pages. - Matthew Wilcox's series "PageFlags cleanups" does that. - Qi Zheng's series "minor fixes and supplement for ptdesc" does that also. S390 is affected. - Cleanups to our pagemap utility functions from Peter Xu in his series "mm/treewide: Replace pXd_large() with pXd_leaf()". - Nico Pache has fixed a few things with our hugepage selftests in his series "selftests/mm: Improve Hugepage Test Handling in MM Selftests". - Also, of course, many singleton patches to many things. Please see the individual changelogs for details. * tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits) mm/zswap: remove the memcpy if acomp is not sleepable crypto: introduce: acomp_is_async to expose if comp drivers might sleep memtest: use {READ,WRITE}_ONCE in memory scanning mm: prohibit the last subpage from reusing the entire large folio mm: recover pud_leaf() definitions in nopmd case selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements selftests/mm: skip uffd hugetlb tests with insufficient hugepages selftests/mm: dont fail testsuite due to a lack of hugepages mm/huge_memory: skip invalid debugfs new_order input for folio split mm/huge_memory: check new folio order when split a folio mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure mm: add an explicit smp_wmb() to UFFDIO_CONTINUE mm: fix list corruption in put_pages_list mm: remove folio from deferred split list before uncharging it filemap: avoid unnecessary major faults in filemap_fault() mm,page_owner: drop unnecessary check mm,page_owner: check for null stack_record before bumping its refcount mm: swap: fix race between free_swap_and_cache() and swapoff() mm/treewide: align up pXd_leaf() retval across archs mm/treewide: drop pXd_large() ...
2024-03-12sched/balancing: Rename scheduler_tick() => sched_tick()Ingo Molnar
- Standardize on prefixing scheduler-internal functions defined in <linux/sched.h> with sched_*() prefix. scheduler_tick() was the only function using the scheduler_ prefix. Harmonize it. - The other reason to rename it is the NOHZ scheduler tick handling functions are already named sched_tick_*(). Make the 'git grep sched_tick' more meaningful. Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Valentin Schneider <vschneid@redhat.com> Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> Link: https://lore.kernel.org/r/20240308111819.1101550-3-mingo@kernel.org
2024-03-11Merge tag 'rcu.next.v6.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/boqun/linux Pull RCU updates from Boqun Feng: - Eliminate deadlocks involving do_exit() and RCU tasks, by Paul: Instead of SRCU read side critical sections, now a percpu list is used in do_exit() for scaning yet-to-exit tasks - Fix a deadlock due to the dependency between workqueue and RCU expedited grace period, reported by Anna-Maria Behnsen and Thomas Gleixner and fixed by Frederic: Now RCU expedited always uses its own kthread worker instead of a workqueue - RCU NOCB updates, code cleanups, unnecessary barrier removals and minor bug fixes - Maintain real-time response in rcu_tasks_postscan() and a minor fix for tasks trace quiescence check - Misc updates, comments and readibility improvement, boot time parameter for lazy RCU and rcutorture improvement - Documentation updates * tag 'rcu.next.v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/boqun/linux: (34 commits) rcu-tasks: Maintain real-time response in rcu_tasks_postscan() rcu-tasks: Eliminate deadlocks involving do_exit() and RCU tasks rcu-tasks: Maintain lists to eliminate RCU-tasks/do_exit() deadlocks rcu-tasks: Initialize data to eliminate RCU-tasks/do_exit() deadlocks rcu-tasks: Initialize callback lists at rcu_init() time rcu-tasks: Add data to eliminate RCU-tasks/do_exit() deadlocks rcu-tasks: Repair RCU Tasks Trace quiescence check rcu/sync: remove un-used rcu_sync_enter_start function rcutorture: Suppress rtort_pipe_count warnings until after stalls srcu: Improve comments about acceleration leak rcu: Provide a boot time parameter to control lazy RCU rcu: Rename jiffies_till_flush to jiffies_lazy_flush doc: Update checklist.rst discussion of callback execution doc: Clarify use of slab constructors and SLAB_TYPESAFE_BY_RCU context_tracking: Fix kerneldoc headers for __ct_user_{enter,exit}() doc: Add EARLY flag to early-parsed kernel boot parameters doc: Add CONFIG_RCU_STRICT_GRACE_PERIOD to checklist.rst doc: Make checklist.rst note that spinlocks are implied RCU readers doc: Make whatisRCU.rst note that spinlocks are RCU readers doc: Spinlocks are implied RCU readers ...
2024-03-10mm: introduce PF_MEMALLOC_NORECLAIM, PF_MEMALLOC_NOWARNKent Overstreet
Introduce PF_MEMALLOC_* equivalents of some GFP_ flags: PF_MEMALLOC_NORECLAIM -> GFP_NOWAIT PF_MEMALLOC_NOWARN -> __GFP_NOWARN Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Darrick J. Wong <djwong@kernel.org> Cc: linux-mm@kvack.org Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-25rcu-tasks: Add data to eliminate RCU-tasks/do_exit() deadlocksPaul E. McKenney
Holding a mutex across synchronize_rcu_tasks() and acquiring that same mutex in code called from do_exit() after its call to exit_tasks_rcu_start() but before its call to exit_tasks_rcu_stop() results in deadlock. This is by design, because tasks that are far enough into do_exit() are no longer present on the tasks list, making it a bit difficult for RCU Tasks to find them, let alone wait on them to do a voluntary context switch. However, such deadlocks are becoming more frequent. In addition, lockdep currently does not detect such deadlocks and they can be difficult to reproduce. In addition, if a task voluntarily context switches during that time (for example, if it blocks acquiring a mutex), then this task is in an RCU Tasks quiescent state. And with some adjustments, RCU Tasks could just as well take advantage of that fact. This commit therefore adds the data structures that will be needed to rely on these quiescent states and to eliminate these deadlocks. Link: https://lore.kernel.org/all/20240118021842.290665-1-chenzhongjin@huawei.com/ Reported-by: Chen Zhongjin <chenzhongjin@huawei.com> Reported-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Yang Jihong <yangjihong1@huawei.com> Tested-by: Chen Zhongjin <chenzhongjin@huawei.com> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
2024-02-22mm: document memalloc_noreclaim_save() and memalloc_pin_save()Vlastimil Babka
The memalloc_noreclaim_save() function currently has no documentation comment, so the implications of its usage are not obvious. Namely that it not only prevents entering reclaim (as the name suggests), but also allows using all memory reserves and thus should be only used in contexts that are allocating memory to free memory. This may lead to new improper usages being added. Thus add a documenting comment, based on the description of __GFP_MEMALLOC. While at it, also document memalloc_pin_save() so that all the memalloc_ scopes are documented. For those already documented, add missing Return: descriptions, and mark Context: description per kernel-docs style guide. In the comments describing the relevant PF_MEMALLOC flags, refer to their scope setting functions. [vbabka@suse.cz: fix issues that Mike pointed out] Link: https://lkml.kernel.org/r/20240215095827.13756-2-vbabka@suse.cz Link: https://lkml.kernel.org/r/20240212182950.32730-2-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/mempolicy: introduce MPOL_WEIGHTED_INTERLEAVE for weighted interleavingGregory Price
When a system has multiple NUMA nodes and it becomes bandwidth hungry, using the current MPOL_INTERLEAVE could be an wise option. However, if those NUMA nodes consist of different types of memory such as socket-attached DRAM and CXL/PCIe attached DRAM, the round-robin based interleave policy does not optimally distribute data to make use of their different bandwidth characteristics. Instead, interleave is more effective when the allocation policy follows each NUMA nodes' bandwidth weight rather than a simple 1:1 distribution. This patch introduces a new memory policy, MPOL_WEIGHTED_INTERLEAVE, enabling weighted interleave between NUMA nodes. Weighted interleave allows for proportional distribution of memory across multiple numa nodes, preferably apportioned to match the bandwidth of each node. For example, if a system has 1 CPU node (0), and 2 memory nodes (0,1), with bandwidth of (100GB/s, 50GB/s) respectively, the appropriate weight distribution is (2:1). Weights for each node can be assigned via the new sysfs extension: /sys/kernel/mm/mempolicy/weighted_interleave/ For now, the default value of all nodes will be `1`, which matches the behavior of standard 1:1 round-robin interleave. An extension will be added in the future to allow default values to be registered at kernel and device bringup time. The policy allocates a number of pages equal to the set weights. For example, if the weights are (2,1), then 2 pages will be allocated on node0 for every 1 page allocated on node1. The new flag MPOL_WEIGHTED_INTERLEAVE can be used in set_mempolicy(2) and mbind(2). Some high level notes about the pieces of weighted interleave: current->il_prev: Tracks the node previously allocated from. current->il_weight: The active weight of the current node (current->il_prev) When this reaches 0, current->il_prev is set to the next node and current->il_weight is set to the next weight. weighted_interleave_nodes: Counts the number of allocations as they occur, and applies the weight for the current node. When the weight reaches 0, switch to the next node. Operates only on task->mempolicy. weighted_interleave_nid: Gets the total weight of the nodemask as well as each individual node weight, then calculates the node based on the given index. Operates on VMA policies. bulk_array_weighted_interleave: Gets the total weight of the nodemask as well as each individual node weight, then calculates the number of "interleave rounds" as well as any delta ("partial round"). Calculates the number of pages for each node and allocates them. If a node was scheduled for interleave via interleave_nodes, the current weight will be allocated first. Operates only on the task->mempolicy. One piece of complexity is the interaction between a recent refactor which split the logic to acquire the "ilx" (interleave index) of an allocation and the actually application of the interleave. If a call to alloc_pages_mpol() were made with a weighted-interleave policy and ilx set to NO_INTERLEAVE_INDEX, weighted_interleave_nodes() would operate on a VMA policy - violating the description above. An inspection of all callers of alloc_pages_mpol() shows that all external callers set ilx to `0`, an index value, or will call get_vma_policy() to acquire the ilx. For example, mm/shmem.c may call into alloc_pages_mpol. The call stacks all set (pgoff_t ilx) or end up in `get_vma_policy()`. This enforces the `weighted_interleave_nodes()` and `weighted_interleave_nid()` policy requirements (task/vma respectively). Link: https://lkml.kernel.org/r/20240202170238.90004-4-gregory.price@memverge.com Suggested-by: Hasan Al Maruf <Hasan.Maruf@amd.com> Signed-off-by: Gregory Price <gregory.price@memverge.com> Co-developed-by: Rakie Kim <rakie.kim@sk.com> Signed-off-by: Rakie Kim <rakie.kim@sk.com> Co-developed-by: Honggyu Kim <honggyu.kim@sk.com> Signed-off-by: Honggyu Kim <honggyu.kim@sk.com> Co-developed-by: Hyeongtak Ji <hyeongtak.ji@sk.com> Signed-off-by: Hyeongtak Ji <hyeongtak.ji@sk.com> Co-developed-by: Srinivasulu Thanneeru <sthanneeru.opensrc@micron.com> Signed-off-by: Srinivasulu Thanneeru <sthanneeru.opensrc@micron.com> Co-developed-by: Ravi Jonnalagadda <ravis.opensrc@micron.com> Signed-off-by: Ravi Jonnalagadda <ravis.opensrc@micron.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-05block: update cached timestamp post schedule/preemptionJens Axboe
Mark the task as having a cached timestamp when set assign it, so we can efficiently check if it needs updating post being scheduled back in. This covers both the actual schedule out case, which would've flushed the plug, and the preemption case which doesn't touch the plugged requests (for many reasons, one of them being then we'd need to have preemption disabled around plug state manipulation). Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-24exec: Distinguish in_execve from in_execKees Cook
Just to help distinguish the fs->in_exec flag from the current->in_execve flag, add comments in check_unsafe_exec() and copy_fs() for more context. Also note that in_execve is only used by TOMOYO now. Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Signed-off-by: Kees Cook <keescook@chromium.org>
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