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2018-04-20mm: memcg: add __GFP_NOWARN in __memcg_schedule_kmem_cache_create()Minchan Kim
If there is heavy memory pressure, page allocation with __GFP_NOWAIT fails easily although it's order-0 request. I got below warning 9 times for normal boot. <snip >: page allocation failure: order:0, mode:0x2200000(GFP_NOWAIT|__GFP_NOTRACK) .. snip .. Call trace: dump_backtrace+0x0/0x4 dump_stack+0xa4/0xc0 warn_alloc+0xd4/0x15c __alloc_pages_nodemask+0xf88/0x10fc alloc_slab_page+0x40/0x18c new_slab+0x2b8/0x2e0 ___slab_alloc+0x25c/0x464 __kmalloc+0x394/0x498 memcg_kmem_get_cache+0x114/0x2b8 kmem_cache_alloc+0x98/0x3e8 mmap_region+0x3bc/0x8c0 do_mmap+0x40c/0x43c vm_mmap_pgoff+0x15c/0x1e4 sys_mmap+0xb0/0xc8 el0_svc_naked+0x24/0x28 Mem-Info: active_anon:17124 inactive_anon:193 isolated_anon:0 active_file:7898 inactive_file:712955 isolated_file:55 unevictable:0 dirty:27 writeback:18 unstable:0 slab_reclaimable:12250 slab_unreclaimable:23334 mapped:19310 shmem:212 pagetables:816 bounce:0 free:36561 free_pcp:1205 free_cma:35615 Node 0 active_anon:68496kB inactive_anon:772kB active_file:31592kB inactive_file:2851820kB unevictable:0kB isolated(anon):0kB isolated(file):220kB mapped:77240kB dirty:108kB writeback:72kB shmem:848kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no DMA free:142188kB min:3056kB low:3820kB high:4584kB active_anon:10052kB inactive_anon:12kB active_file:312kB inactive_file:1412620kB unevictable:0kB writepending:0kB present:1781412kB managed:1604728kB mlocked:0kB slab_reclaimable:3592kB slab_unreclaimable:876kB kernel_stack:400kB pagetables:52kB bounce:0kB free_pcp:1436kB local_pcp:124kB free_cma:142492kB lowmem_reserve[]: 0 1842 1842 Normal free:4056kB min:4172kB low:5212kB high:6252kB active_anon:58376kB inactive_anon:760kB active_file:31348kB inactive_file:1439040kB unevictable:0kB writepending:180kB present:2000636kB managed:1923688kB mlocked:0kB slab_reclaimable:45408kB slab_unreclaimable:92460kB kernel_stack:9680kB pagetables:3212kB bounce:0kB free_pcp:3392kB local_pcp:688kB free_cma:0kB lowmem_reserve[]: 0 0 0 DMA: 0*4kB 0*8kB 1*16kB (C) 0*32kB 0*64kB 0*128kB 1*256kB (C) 1*512kB (C) 0*1024kB 1*2048kB (C) 34*4096kB (C) = 142096kB Normal: 228*4kB (UMEH) 172*8kB (UMH) 23*16kB (UH) 24*32kB (H) 5*64kB (H) 1*128kB (H) 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 3872kB 721350 total pagecache pages 0 pages in swap cache Swap cache stats: add 0, delete 0, find 0/0 Free swap = 0kB Total swap = 0kB 945512 pages RAM 0 pages HighMem/MovableOnly 63408 pages reserved 51200 pages cma reserved __memcg_schedule_kmem_cache_create() tries to create a shadow slab cache and the worker allocation failure is not really critical because we will retry on the next kmem charge. We might miss some charges but that shouldn't be critical. The excessive allocation failure report is not very helpful. [mhocko@kernel.org: changelog update] Link: http://lkml.kernel.org/r/20180418022912.248417-1-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11page cache: use xa_lockMatthew Wilcox
Remove the address_space ->tree_lock and use the xa_lock newly added to the radix_tree_root. Rename the address_space ->page_tree to ->i_pages, since we don't really care that it's a tree. [willy@infradead.org: fix nds32, fs/dax.c] Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Jeff Layton <jlayton@redhat.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11memcg: fix per_node_info cleanupMichal Hocko
syzbot has triggered a NULL ptr dereference when allocation fault injection enforces a failure and alloc_mem_cgroup_per_node_info initializes memcg->nodeinfo only half way through. But __mem_cgroup_free still tries to free all per-node data and dereferences pn->lruvec_stat_cpu unconditioanlly even if the specific per-node data hasn't been initialized. The bug is quite unlikely to hit because small allocations do not fail and we would need quite some numa nodes to make struct mem_cgroup_per_node large enough to cross the costly order. Link: http://lkml.kernel.org/r/20180406100906.17790-1-mhocko@kernel.org Reported-by: syzbot+8a5de3cce7cdc70e9ebe@syzkaller.appspotmail.com Fixes: 00f3ca2c2d66 ("mm: memcontrol: per-lruvec stats infrastructure") Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11mm: memcg: make sure memory.events is uptodate when waking pollersJohannes Weiner
Commit a983b5ebee57 ("mm: memcontrol: fix excessive complexity in memory.stat reporting") added per-cpu drift to all memory cgroup stats and events shown in memory.stat and memory.events. For memory.stat this is acceptable. But memory.events issues file notifications, and somebody polling the file for changes will be confused when the counters in it are unchanged after a wakeup. Luckily, the events in memory.events - MEMCG_LOW, MEMCG_HIGH, MEMCG_MAX, MEMCG_OOM - are sufficiently rare and high-level that we don't need per-cpu buffering for them: MEMCG_HIGH and MEMCG_MAX would be the most frequent, but they're counting invocations of reclaim, which is a complex operation that touches many shared cachelines. This splits memory.events from the generic VM events and tracks them in their own, unbuffered atomic counters. That's also cleaner, as it eliminates the ugly enum nesting of VM and cgroup events. [hannes@cmpxchg.org: "array subscript is above array bounds"] Link: http://lkml.kernel.org/r/20180406155441.GA20806@cmpxchg.org Link: http://lkml.kernel.org/r/20180405175507.GA24817@cmpxchg.org Fixes: a983b5ebee57 ("mm: memcontrol: fix excessive complexity in memory.stat reporting") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Tejun Heo <tj@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: Rik van Riel <riel@surriel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11memcg, thp: do not invoke oom killer on thp chargesMichal Hocko
A THP memcg charge can trigger the oom killer since 2516035499b9 ("mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations"). We have used an explicit __GFP_NORETRY previously which ruled the OOM killer automagically. Memcg charge path should be semantically compliant with the allocation path and that means that if we do not trigger the OOM killer for costly orders which should do the same in the memcg charge path as well. Otherwise we are forcing callers to distinguish the two and use different gfp masks which is both non-intuitive and bug prone. As soon as we get a costly high order kmalloc user we even do not have any means to tell the memcg specific gfp mask to prevent from OOM because the charging is deep within guts of the slab allocator. The unexpected memcg OOM on THP has already been fixed upstream by 9d3c3354bb85 ("mm, thp: do not cause memcg oom for thp") but this is a one-off fix rather than a generic solution. Teach mem_cgroup_oom to bail out on costly order requests to fix the THP issue as well as any other costly OOM eligible allocations to be added in future. Also revert 9d3c3354bb85 because special gfp for THP is no longer needed. Link: http://lkml.kernel.org/r/20180403193129.22146-1-mhocko@kernel.org Fixes: 2516035499b9 ("mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations") Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-28mm/memcontrol.c: fix parameter description mismatchHonglei Wang
There are a couple of places where parameter description and function name do not match the actual code. Fix it. Link: http://lkml.kernel.org/r/1520843448-17347-1-git-send-email-honglei.wang@oracle.com Signed-off-by: Honglei Wang <honglei.wang@oracle.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06mm: docs: fix parameter names mismatchMike Rapoport
There are several places where parameter descriptions do no match the actual code. Fix it. Link: http://lkml.kernel.org/r/1516700871-22279-3-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06mm: docs: fixup punctuationMike Rapoport
so that kernel-doc will properly recognize the parameter and function descriptions. Link: http://lkml.kernel.org/r/1516700871-22279-2-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-02Revert "defer call to mem_cgroup_sk_alloc()"Roman Gushchin
This patch effectively reverts commit 9f1c2674b328 ("net: memcontrol: defer call to mem_cgroup_sk_alloc()"). Moving mem_cgroup_sk_alloc() to the inet_csk_accept() completely breaks memcg socket memory accounting, as packets received before memcg pointer initialization are not accounted and are causing refcounting underflow on socket release. Actually the free-after-use problem was fixed by commit c0576e397508 ("net: call cgroup_sk_alloc() earlier in sk_clone_lock()") for the cgroup pointer. So, let's revert it and call mem_cgroup_sk_alloc() just before cgroup_sk_alloc(). This is safe, as we hold a reference to the socket we're cloning, and it holds a reference to the memcg. Also, let's drop BUG_ON(mem_cgroup_is_root()) check from mem_cgroup_sk_alloc(). I see no reasons why bumping the root memcg counter is a good reason to panic, and there are no realistic ways to hit it. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Eric Dumazet <edumazet@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-31mm/memcontrol.c: try harder to decrease [memory,memsw].limit_in_bytesAndrey Ryabinin
mem_cgroup_resize_[memsw]_limit() tries to free only 32 (SWAP_CLUSTER_MAX) pages on each iteration. This makes it practically impossible to decrease limit of memory cgroup. Tasks could easily allocate back 32 pages, so we can't reduce memory usage, and once retry_count reaches zero we return -EBUSY. Easy to reproduce the problem by running the following commands: mkdir /sys/fs/cgroup/memory/test echo $$ >> /sys/fs/cgroup/memory/test/tasks cat big_file > /dev/null & sleep 1 && echo $((100*1024*1024)) > /sys/fs/cgroup/memory/test/memory.limit_in_bytes -bash: echo: write error: Device or resource busy Instead of relying on retry_count, keep retrying the reclaim until the desired limit is reached or fail if the reclaim doesn't make any progress or a signal is pending. Link: http://lkml.kernel.org/r/20180119132544.19569-1-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31mm/memcontrol.c: make local symbol staticChristopher Díaz Riveros
Fix the following sparse warning: mm/memcontrol.c:1097:14: warning: symbol 'memcg1_stats' was not declared. Should it be static? Link: http://lkml.kernel.org/r/20180118193327.14200-1-chrisadr@gentoo.org Signed-off-by: Christopher Díaz Riveros <chrisadr@gentoo.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31memcg: refactor mem_cgroup_resize_limit()Yu Zhao
mem_cgroup_resize_limit() and mem_cgroup_resize_memsw_limit() have identical logics. Refactor code so we don't need to keep two pieces of code that does same thing. Link: http://lkml.kernel.org/r/20180108224238.14583-1-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31mm: memcontrol: fix excessive complexity in memory.stat reportingJohannes Weiner
We've seen memory.stat reads in top-level cgroups take up to fourteen seconds during a userspace bug that created tens of thousands of ghost cgroups pinned by lingering page cache. Even with a more reasonable number of cgroups, aggregating memory.stat is unnecessarily heavy. The complexity is this: nr_cgroups * nr_stat_items * nr_possible_cpus where the stat items are ~70 at this point. With 128 cgroups and 128 CPUs - decent, not enormous setups - reading the top-level memory.stat has to aggregate over a million per-cpu counters. This doesn't scale. Instead of spreading the source of truth across all CPUs, use the per-cpu counters merely to batch updates to shared atomic counters. This is the same as the per-cpu stocks we use for charging memory to the shared atomic page_counters, and also the way the global vmstat counters are implemented. Vmstat has elaborate spilling thresholds that depend on the number of CPUs, amount of memory, and memory pressure - carefully balancing the cost of counter updates with the amount of per-cpu error. That's because the vmstat counters are system-wide, but also used for decisions inside the kernel (e.g. NR_FREE_PAGES in the allocator). Neither is true for the memory controller. Use the same static batch size we already use for page_counter updates during charging. The per-cpu error in the stats will be 128k, which is an acceptable ratio of cores to memory accounting granularity. [hannes@cmpxchg.org: fix warning in __this_cpu_xchg() calls] Link: http://lkml.kernel.org/r/20171201135750.GB8097@cmpxchg.org Link: http://lkml.kernel.org/r/20171103153336.24044-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31mm: memcontrol: eliminate raw access to stat and event countersJohannes Weiner
Replace all raw 'this_cpu_' modifications of the stat and event per-cpu counters with API functions such as mod_memcg_state(). This makes the code easier to read, but is also in preparation for the next patch, which changes the per-cpu implementation of those counters. Link: http://lkml.kernel.org/r/20171103153336.24044-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-30Merge branch 'misc.poll' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull poll annotations from Al Viro: "This introduces a __bitwise type for POLL### bitmap, and propagates the annotations through the tree. Most of that stuff is as simple as 'make ->poll() instances return __poll_t and do the same to local variables used to hold the future return value'. Some of the obvious brainos found in process are fixed (e.g. POLLIN misspelled as POLL_IN). At that point the amount of sparse warnings is low and most of them are for genuine bugs - e.g. ->poll() instance deciding to return -EINVAL instead of a bitmap. I hadn't touched those in this series - it's large enough as it is. Another problem it has caught was eventpoll() ABI mess; select.c and eventpoll.c assumed that corresponding POLL### and EPOLL### were equal. That's true for some, but not all of them - EPOLL### are arch-independent, but POLL### are not. The last commit in this series separates userland POLL### values from the (now arch-independent) kernel-side ones, converting between them in the few places where they are copied to/from userland. AFAICS, this is the least disruptive fix preserving poll(2) ABI and making epoll() work on all architectures. As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and it will trigger only on what would've triggered EPOLLWRBAND on other architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered at all on sparc. With this patch they should work consistently on all architectures" * 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits) make kernel-side POLL... arch-independent eventpoll: no need to mask the result of epi_item_poll() again eventpoll: constify struct epoll_event pointers debugging printk in sg_poll() uses %x to print POLL... bitmap annotate poll(2) guts 9p: untangle ->poll() mess ->si_band gets POLL... bitmap stored into a user-visible long field ring_buffer_poll_wait() return value used as return value of ->poll() the rest of drivers/*: annotate ->poll() instances media: annotate ->poll() instances fs: annotate ->poll() instances ipc, kernel, mm: annotate ->poll() instances net: annotate ->poll() instances apparmor: annotate ->poll() instances tomoyo: annotate ->poll() instances sound: annotate ->poll() instances acpi: annotate ->poll() instances crypto: annotate ->poll() instances block: annotate ->poll() instances x86: annotate ->poll() instances ...
2017-11-29mm, memcg: fix mem_cgroup_swapout() for THPsShakeel Butt
Commit d6810d730022 ("memcg, THP, swap: make mem_cgroup_swapout() support THP") changed mem_cgroup_swapout() to support transparent huge page (THP). However the patch missed one location which should be changed for correctly handling THPs. The resulting bug will cause the memory cgroups whose THPs were swapped out to become zombies on deletion. Link: http://lkml.kernel.org/r/20171128161941.20931-1-shakeelb@google.com Fixes: d6810d730022 ("memcg, THP, swap: make mem_cgroup_swapout() support THP") Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Greg Thelen <gthelen@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-27annotate poll-related wait keysAl Viro
__poll_t is also used as wait key in some waitqueues. Verify that wait_..._poll() gets __poll_t as key and provide a helper for wakeup functions to get back to that __poll_t value. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-15mm: slabinfo: remove CONFIG_SLABINFOYang Shi
According to discussion with Christoph (https://marc.info/?l=linux-kernel&m=150695909709711&w=2), it sounds like it is pointless to keep CONFIG_SLABINFO around. This patch removes the CONFIG_SLABINFO config option, but /proc/slabinfo is still available. [yang.s@alibaba-inc.com: v11] Link: http://lkml.kernel.org/r/1507656303-103845-3-git-send-email-yang.s@alibaba-inc.com Link: http://lkml.kernel.org/r/1507152550-46205-3-git-send-email-yang.s@alibaba-inc.com Signed-off-by: Yang Shi <yang.s@alibaba-inc.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-09net: memcontrol: defer call to mem_cgroup_sk_alloc()Eric Dumazet
Instead of calling mem_cgroup_sk_alloc() from BH context, it is better to call it from inet_csk_accept() in process context. Not only this removes code in mem_cgroup_sk_alloc(), but it also fixes a bug since listener might have been dismantled and css_get() might cause a use-after-free. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-03mm/memcg: avoid page count check for zone deviceJérôme Glisse
Fix for 4.14, zone device page always have an elevated refcount of one and thus page count sanity check in uncharge_page() is inappropriate for them. [mhocko@suse.com: nano-optimize VM_BUG_ON in uncharge_page] Link: http://lkml.kernel.org/r/20170914190011.5217-1-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Evgeny Baskakov <ebaskakov@nvidia.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03mm, memcg: remove hotplug locking from try_chargeMichal Hocko
The following lockdep splat has been noticed during LTP testing ====================================================== WARNING: possible circular locking dependency detected 4.13.0-rc3-next-20170807 #12 Not tainted ------------------------------------------------------ a.out/4771 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){++++++}, at: [<ffffffff812b4668>] drain_all_stock.part.35+0x18/0x140 but task is already holding lock: (&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&mm->mmap_sem){++++++}: lock_acquire+0xc9/0x230 __might_fault+0x70/0xa0 _copy_to_user+0x23/0x70 filldir+0xa7/0x110 xfs_dir2_sf_getdents.isra.10+0x20c/0x2c0 [xfs] xfs_readdir+0x1fa/0x2c0 [xfs] xfs_file_readdir+0x30/0x40 [xfs] iterate_dir+0x17a/0x1a0 SyS_getdents+0xb0/0x160 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #2 (&type->i_mutex_dir_key#3){++++++}: lock_acquire+0xc9/0x230 down_read+0x51/0xb0 lookup_slow+0xde/0x210 walk_component+0x160/0x250 link_path_walk+0x1a6/0x610 path_openat+0xe4/0xd50 do_filp_open+0x91/0x100 file_open_name+0xf5/0x130 filp_open+0x33/0x50 kernel_read_file_from_path+0x39/0x80 _request_firmware+0x39f/0x880 request_firmware_direct+0x37/0x50 request_microcode_fw+0x64/0xe0 reload_store+0xf7/0x180 dev_attr_store+0x18/0x30 sysfs_kf_write+0x44/0x60 kernfs_fop_write+0x113/0x1a0 __vfs_write+0x37/0x170 vfs_write+0xc7/0x1c0 SyS_write+0x58/0xc0 do_syscall_64+0x6c/0x1f0 return_from_SYSCALL_64+0x0/0x7a -> #1 (microcode_mutex){+.+.+.}: lock_acquire+0xc9/0x230 __mutex_lock+0x88/0x960 mutex_lock_nested+0x1b/0x20 microcode_init+0xbb/0x208 do_one_initcall+0x51/0x1a9 kernel_init_freeable+0x208/0x2a7 kernel_init+0xe/0x104 ret_from_fork+0x2a/0x40 -> #0 (cpu_hotplug_lock.rw_sem){++++++}: __lock_acquire+0x153c/0x1550 lock_acquire+0xc9/0x230 cpus_read_lock+0x4b/0x90 drain_all_stock.part.35+0x18/0x140 try_charge+0x3ab/0x6e0 mem_cgroup_try_charge+0x7f/0x2c0 shmem_getpage_gfp+0x25f/0x1050 shmem_fault+0x96/0x200 __do_fault+0x1e/0xa0 __handle_mm_fault+0x9c3/0xe00 handle_mm_fault+0x16e/0x380 __do_page_fault+0x24a/0x530 do_page_fault+0x30/0x80 page_fault+0x28/0x30 other info that might help us debug this: Chain exists of: cpu_hotplug_lock.rw_sem --> &type->i_mutex_dir_key#3 --> &mm->mmap_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(&type->i_mutex_dir_key#3); lock(&mm->mmap_sem); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** 2 locks held by a.out/4771: #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530 #1: (percpu_charge_mutex){+.+...}, at: [<ffffffff812b4c97>] try_charge+0x397/0x6e0 The problem is very similar to the one fixed by commit a459eeb7b852 ("mm, page_alloc: do not depend on cpu hotplug locks inside the allocator"). We are taking hotplug locks while we can be sitting on top of basically arbitrary locks. This just calls for problems. We can get rid of {get,put}_online_cpus, fortunately. We do not have to be worried about races with memory hotplug because drain_local_stock, which is called from both the WQ draining and the memory hotplug contexts, is always operating on the local cpu stock with IRQs disabled. The only thing to be careful about is that the target memcg doesn't vanish while we are still in drain_all_stock so take a reference on it. Link: http://lkml.kernel.org/r/20170913090023.28322-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Artem Savkov <asavkov@redhat.com> Tested-by: Artem Savkov <asavkov@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08mem/memcg: cache rightmost nodeDavidlohr Bueso
Such that we can optimize __mem_cgroup_largest_soft_limit_node(). The only overhead is the extra footprint for the cached pointer, but this should not be an issue for mem_cgroup_tree_per_node. [dave@stgolabs.net: brain fart #2] Link: http://lkml.kernel.org/r/20170731160114.GE21328@linux-80c1.suse Link: http://lkml.kernel.org/r/20170719014603.19029-17-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08mm: memcontrol: use per-cpu stocks for socket memory unchargingRoman Gushchin
We've noticed a quite noticeable performance overhead on some hosts with significant network traffic when socket memory accounting is enabled. Perf top shows that socket memory uncharging path is hot: 2.13% [kernel] [k] page_counter_cancel 1.14% [kernel] [k] __sk_mem_reduce_allocated 1.14% [kernel] [k] _raw_spin_lock 0.87% [kernel] [k] _raw_spin_lock_irqsave 0.84% [kernel] [k] tcp_ack 0.84% [kernel] [k] ixgbe_poll 0.83% < workload > 0.82% [kernel] [k] enqueue_entity 0.68% [kernel] [k] __fget 0.68% [kernel] [k] tcp_delack_timer_handler 0.67% [kernel] [k] __schedule 0.60% < workload > 0.59% [kernel] [k] __inet6_lookup_established 0.55% [kernel] [k] __switch_to 0.55% [kernel] [k] menu_select 0.54% libc-2.20.so [.] __memcpy_avx_unaligned To address this issue, the existing per-cpu stock infrastructure can be used. refill_stock() can be called from mem_cgroup_uncharge_skmem() to move charge to a per-cpu stock instead of calling atomic page_counter_uncharge(). To prevent the uncontrolled growth of per-cpu stocks, refill_stock() will explicitly drain the cached charge, if the cached value exceeds CHARGE_BATCH. This allows significantly optimize the load: 1.21% [kernel] [k] _raw_spin_lock 1.01% [kernel] [k] ixgbe_poll 0.92% [kernel] [k] _raw_spin_lock_irqsave 0.90% [kernel] [k] enqueue_entity 0.86% [kernel] [k] tcp_ack 0.85% < workload > 0.74% perf-11120.map [.] 0x000000000061bf24 0.73% [kernel] [k] __schedule 0.67% [kernel] [k] __fget 0.63% [kernel] [k] __inet6_lookup_established 0.62% [kernel] [k] menu_select 0.59% < workload > 0.59% [kernel] [k] __switch_to 0.57% libc-2.20.so [.] __memcpy_avx_unaligned Link: http://lkml.kernel.org/r/20170829100150.4580-1-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08mm/device-public-memory: device memory cache coherent with CPUJérôme Glisse
Platform with advance system bus (like CAPI or CCIX) allow device memory to be accessible from CPU in a cache coherent fashion. Add a new type of ZONE_DEVICE to represent such memory. The use case are the same as for the un-addressable device memory but without all the corners cases. Link: http://lkml.kernel.org/r/20170817000548.32038-19-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08mm/memcontrol: support MEMORY_DEVICE_PRIVATEJérôme Glisse
HMM pages (private or public device pages) are ZONE_DEVICE page and thus need special handling when it comes to lru or refcount. This patch make sure that memcontrol properly handle those when it face them. Those pages are use like regular pages in a process address space either as anonymous page or as file back page. So from memcg point of view we want to handle them like regular page for now at least. Link: http://lkml.kernel.org/r/20170817000548.32038-11-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08mm/memcontrol: allow to uncharge page without using page->lru fieldJérôme Glisse
HMM pages (private or public device pages) are ZONE_DEVICE page and thus you can not use page->lru fields of those pages. This patch re-arrange the uncharge to allow single page to be uncharge without modifying the lru field of the struct page. There is no change to memcontrol logic, it is the same as it was before this patch. Link: http://lkml.kernel.org/r/20170817000548.32038-10-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08mm: thp: check pmd migration entry in common pathZi Yan
When THP migration is being used, memory management code needs to handle pmd migration entries properly. This patch uses !pmd_present() or is_swap_pmd() (depending on whether pmd_none() needs separate code or not) to check pmd migration entries at the places where a pmd entry is present. Since pmd-related code uses split_huge_page(), split_huge_pmd(), pmd_trans_huge(), pmd_trans_unstable(), or pmd_none_or_trans_huge_or_clear_bad(), this patch: 1. adds pmd migration entry split code in split_huge_pmd(), 2. takes care of pmd migration entries whenever pmd_trans_huge() is present, 3. makes pmd_none_or_trans_huge_or_clear_bad() pmd migration entry aware. Since split_huge_page() uses split_huge_pmd() and pmd_trans_unstable() is equivalent to pmd_none_or_trans_huge_or_clear_bad(), we do not change them. Until this commit, a pmd entry should be: 1. pointing to a pte page, 2. is_swap_pmd(), 3. pmd_trans_huge(), 4. pmd_devmap(), or 5. pmd_none(). Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06Merge branch 'for-4.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Several notable changes this cycle: - Thread mode was merged. This will be used for cgroup2 support for CPU and possibly other controllers. Unfortunately, CPU controller cgroup2 support didn't make this pull request but most contentions have been resolved and the support is likely to be merged before the next merge window. - cgroup.stat now shows the number of descendant cgroups. - cpuset now can enable the easier-to-configure v2 behavior on v1 hierarchy" * 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits) cpuset: Allow v2 behavior in v1 cgroup cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup cgroup: remove unneeded checks cgroup: misc changes cgroup: short-circuit cset_cgroup_from_root() on the default hierarchy cgroup: re-use the parent pointer in cgroup_destroy_locked() cgroup: add cgroup.stat interface with basic hierarchy stats cgroup: implement hierarchy limits cgroup: keep track of number of descent cgroups cgroup: add comment to cgroup_enable_threaded() cgroup: remove unnecessary empty check when enabling threaded mode cgroup: update debug controller to print out thread mode information cgroup: implement cgroup v2 thread support cgroup: implement CSS_TASK_ITER_THREADED cgroup: introduce cgroup->dom_cgrp and threaded css_set handling cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS cgroup: reorganize cgroup.procs / task write path cgroup: replace css_set walking populated test with testing cgrp->nr_populated_csets cgroup: distinguish local and children populated states cgroup: remove now unused list_head @pending in cgroup_apply_cftypes() ...
2017-09-06mm: replace TIF_MEMDIE checks by tsk_is_oom_victimMichal Hocko
TIF_MEMDIE is set only to the tasks whick were either directly selected by the OOM killer or passed through mark_oom_victim from the allocator path. tsk_is_oom_victim is more generic and allows to identify all tasks (threads) which share the mm with the oom victim. Please note that the freezer still needs to check TIF_MEMDIE because we cannot thaw tasks which do not participage in oom_victims counting otherwise a !TIF_MEMDIE task could interfere after oom_disbale returns. Link: http://lkml.kernel.org/r/20170810075019.28998-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06memcg, THP, swap: make mem_cgroup_swapout() support THPHuang Ying
This patch makes mem_cgroup_swapout() works for the transparent huge page (THP). Which will move the memory cgroup charge from memory to swap for a THP. This will be used for the THP swap support. Where a THP may be swapped out as a whole to a set of (HPAGE_PMD_NR) continuous swap slots on the swap device. Link: http://lkml.kernel.org/r/20170724051840.2309-11-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Rik van Riel <riel@redhat.com> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Shaohua Li <shli@kernel.org> Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06memcg, THP, swap: avoid to duplicated charge THP in swap cacheHuang Ying
For a THP (Transparent Huge Page), tail_page->mem_cgroup is NULL. So to check whether the page is charged already, we need to check the head page. This is not an issue before because it is impossible for a THP to be in the swap cache before. But after we add delaying splitting THP after swapped out support, it is possible now. Link: http://lkml.kernel.org/r/20170724051840.2309-10-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Rik van Riel <riel@redhat.com> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Shaohua Li <shli@kernel.org> Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06memcg, THP, swap: support move mem cgroup charge for THP swapped outHuang Ying
PTE mapped THP (Transparent Huge Page) will be ignored when moving memory cgroup charge. But for THP which is in the swap cache, the memory cgroup charge for the swap of a tail-page may be moved in current implementation. That isn't correct, because the swap charge for all sub-pages of a THP should be moved together. Following the processing of the PTE mapped THP, the mem cgroup charge moving for the swap entry for a tail-page of a THP is ignored too. Link: http://lkml.kernel.org/r/20170724051840.2309-9-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Rik van Riel <riel@redhat.com> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Shaohua Li <shli@kernel.org> Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06mm: memcontrol: use int for event/state parameter in several functionsMatthias Kaehlcke
Several functions use an enum type as parameter for an event/state, but are called in some locations with an argument of a different enum type. Adjust the interface of these functions to reality by changing the parameter to int. This fixes a ton of enum-conversion warnings that are generated when building the kernel with clang. [mka@chromium.org: also change parameter type of inc/dec/mod_memcg_page_state()] Link: http://lkml.kernel.org/r/20170728213442.93823-1-mka@chromium.org Link: http://lkml.kernel.org/r/20170727211004.34435-1-mka@chromium.org Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Doug Anderson <dianders@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06mm, memcg: reset memory.low during memcg offliningRoman Gushchin
A removed memory cgroup with a defined memory.low and some belonging pagecache has very low chances to be freed. If a cgroup has been removed, there is likely no memory pressure inside the cgroup, and the pagecache is protected from the external pressure by the defined low limit. The cgroup will be freed only after the reclaim of all belonging pages. And it will not happen until there are any reclaimable memory in the system. That means, there is a good chance, that a cold pagecache will reside in the memory for an undefined amount of time, wasting system resources. This problem was fixed earlier by fa06235b8eb0 ("cgroup: reset css on destruction"), but it's not a best way to do it, as we can't really reset all limits/counters during cgroup offlining. Link: http://lkml.kernel.org/r/20170727130428.28856-1-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-18mm: memcontrol: fix NULL pointer crash in test_clear_page_writeback()Johannes Weiner
Jaegeuk and Brad report a NULL pointer crash when writeback ending tries to update the memcg stats: BUG: unable to handle kernel NULL pointer dereference at 00000000000003b0 IP: test_clear_page_writeback+0x12e/0x2c0 [...] RIP: 0010:test_clear_page_writeback+0x12e/0x2c0 Call Trace: <IRQ> end_page_writeback+0x47/0x70 f2fs_write_end_io+0x76/0x180 [f2fs] bio_endio+0x9f/0x120 blk_update_request+0xa8/0x2f0 scsi_end_request+0x39/0x1d0 scsi_io_completion+0x211/0x690 scsi_finish_command+0xd9/0x120 scsi_softirq_done+0x127/0x150 __blk_mq_complete_request_remote+0x13/0x20 flush_smp_call_function_queue+0x56/0x110 generic_smp_call_function_single_interrupt+0x13/0x30 smp_call_function_single_interrupt+0x27/0x40 call_function_single_interrupt+0x89/0x90 RIP: 0010:native_safe_halt+0x6/0x10 (gdb) l *(test_clear_page_writeback+0x12e) 0xffffffff811bae3e is in test_clear_page_writeback (./include/linux/memcontrol.h:619). 614 mod_node_page_state(page_pgdat(page), idx, val); 615 if (mem_cgroup_disabled() || !page->mem_cgroup) 616 return; 617 mod_memcg_state(page->mem_cgroup, idx, val); 618 pn = page->mem_cgroup->nodeinfo[page_to_nid(page)]; 619 this_cpu_add(pn->lruvec_stat->count[idx], val); 620 } 621 622 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, 623 gfp_t gfp_mask, The issue is that writeback doesn't hold a page reference and the page might get freed after PG_writeback is cleared (and the mapping is unlocked) in test_clear_page_writeback(). The stat functions looking up the page's node or zone are safe, as those attributes are static across allocation and free cycles. But page->mem_cgroup is not, and it will get cleared if we race with truncation or migration. It appears this race window has been around for a while, but less likely to trigger when the memcg stats were updated first thing after PG_writeback is cleared. Recent changes reshuffled this code to update the global node stats before the memcg ones, though, stretching the race window out to an extent where people can reproduce the problem. Update test_clear_page_writeback() to look up and pin page->mem_cgroup before clearing PG_writeback, then not use that pointer afterward. It is a partial revert of 62cccb8c8e7a ("mm: simplify lock_page_memcg()") but leaves the pageref-holding callsites that aren't affected alone. Link: http://lkml.kernel.org/r/20170809183825.GA26387@cmpxchg.org Fixes: 62cccb8c8e7a ("mm: simplify lock_page_memcg()") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Jaegeuk Kim <jaegeuk@kernel.org> Tested-by: Jaegeuk Kim <jaegeuk@kernel.org> Reported-by: Bradley Bolen <bradleybolen@gmail.com> Tested-by: Brad Bolen <bradleybolen@gmail.com> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: <stable@vger.kernel.org> [4.6+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-21cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCSTejun Heo
css_task_iter currently always walks all tasks. With the scheduled cgroup v2 thread support, the iterator would need to handle multiple types of iteration. As a preparation, add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS. If the flag is not specified, it walks all tasks as before. When asserted, the iterator only walks the group leaders. For now, the only user of the flag is cgroup v2 "cgroup.procs" file which no longer needs to skip non-leader tasks in cgroup_procs_next(). Note that cgroup v1 "cgroup.procs" can't use the group leader walk as v1 "cgroup.procs" doesn't mean "list all thread group leaders in the cgroup" but "list all thread group id's with any threads in the cgroup". While at it, update cgroup_procs_show() to use task_pid_vnr() instead of task_tgid_vnr(). As the iteration guarantees that the function only sees group leaders, this doesn't change the output and will allow sharing the function for thread iteration. Signed-off-by: Tejun Heo <tj@kernel.org>
2017-07-10mm, memcg: fix potential undefined behavior in mem_cgroup_event_ratelimit()Michal Hocko
Alice has reported the following UBSAN splat: UBSAN: Undefined behaviour in mm/memcontrol.c:661:17 signed integer overflow: -2147483644 - 2147483525 cannot be represented in type 'long int' CPU: 1 PID: 11758 Comm: mybibtex2filena Tainted: P O 4.9.25-gentoo #4 Hardware name: XXXXXX, BIOS YYYYYY Call Trace: dump_stack+0x59/0x87 ubsan_epilogue+0xe/0x40 handle_overflow+0xbb/0xf0 __ubsan_handle_sub_overflow+0x12/0x20 memcg_check_events.isra.36+0x223/0x360 mem_cgroup_commit_charge+0x55/0x140 wp_page_copy+0x34e/0xb80 do_wp_page+0x1e6/0x1300 handle_mm_fault+0x88b/0x1990 __do_page_fault+0x2de/0x8a0 do_page_fault+0x1a/0x20 error_code+0x67/0x6c The reason is that we subtract two signed types. Let's fix this by truly mimicing time_after and cast the result of the subtraction. Link: http://lkml.kernel.org/r/20170616150057.GQ30580@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Alice Ferrazzi <alicef@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10mm/memcontrol: exclude @root from checks in mem_cgroup_lowSean Christopherson
Make @root exclusive in mem_cgroup_low; it is never considered low when looked at directly and is not checked when traversing the tree. In effect, @root is handled identically to how root_mem_cgroup was previously handled by mem_cgroup_low. If @root is not excluded from the checks, a cgroup underneath @root will never be considered low during targeted reclaim of @root, e.g. due to memory.current > memory.high, unless @root is misconfigured to have memory.low > memory.high. Excluding @root enables using memory.low to prioritize memory usage between cgroups within a subtree of the hierarchy that is limited by memory.high or memory.max, e.g. when ROOT owns @root's controls but delegates the @root directory to a USER so that USER can create and administer children of @root. For example, given cgroup A with children B and C: A / \ B C and 1. A/memory.current > A/memory.high 2. A/B/memory.current < A/B/memory.low 3. A/C/memory.current >= A/C/memory.low As 'A' is high, i.e. triggers reclaim from 'A', and 'B' is low, we should reclaim from 'C' until 'A' is no longer high or until we can no longer reclaim from 'C'. If 'A', i.e. @root, isn't excluded by mem_cgroup_low when reclaming from 'A', then 'B' won't be considered low and we will reclaim indiscriminately from both 'B' and 'C'. Here is the test I used to confirm the bug and the patch. 20:00:55@sjchrist-vm ? ~ $ cat ~/.bin/memcg_low_test #!/bin/bash x62mb=$((62<<20)) x66mb=$((66<<20)) x94mb=$((94<<20)) x98mb=$((98<<20)) setup() { set -e if [[ -n $DEBUG ]]; then set -x fi trap teardown EXIT HUP INT TERM if [[ ! -e /mnt/1gb.swap ]]; then sudo fallocate -l 1G /mnt/1gb.swap > /dev/null sudo mkswap /mnt/1gb.swap > /dev/null fi if ! swapon --show=NAME | grep -q "/mnt/1gb.swap"; then sudo swapon /mnt/1gb.swap fi if [[ ! -e /cgroup/cgroup.controllers ]]; then sudo mount -t cgroup2 none /cgroup fi grep -q memory /cgroup/cgroup.controllers sudo sh -c "echo '+memory' > /cgroup/cgroup.subtree_control" sudo mkdir /cgroup/A && sudo chown $USER:$USER /cgroup/A sudo sh -c "echo '+memory' > /cgroup/A/cgroup.subtree_control" sudo sh -c "echo '96m' > /cgroup/A/memory.high" mkdir /cgroup/A/0 mkdir /cgroup/A/1 echo 64m > /cgroup/A/0/memory.low } teardown() { set +e trap - EXIT HUP INT TERM if [[ -z $1 ]]; then printf "\n" printf "%0.s*" {1..35} printf "\nFAILED!\n\n" tail /cgroup/A/**/memory.current printf "%0.s*" {1..35} printf "\n\n" fi ps | grep stress | tr -s ' ' | cut -f 2 -d ' ' | xargs -I % kill % sleep 2 if [[ -e /cgroup/A/0 ]]; then rmdir /cgroup/A/0 fi if [[ -e /cgroup/A/1 ]]; then rmdir /cgroup/A/1 fi if [[ -e /cgroup/A ]]; then sudo rmdir /cgroup/A fi } stress_test() { sudo sh -c "echo $$ > /cgroup/A/$1/cgroup.procs" stress --vm 1 --vm-bytes 64M --vm-keep > /dev/null & sudo sh -c "echo $$ > /cgroup/A/$2/cgroup.procs" stress --vm 1 --vm-bytes 64M --vm-keep > /dev/null & sudo sh -c "echo $$ > /cgroup/cgroup.procs" sleep 1 # A/0 should be consuming more memory than A/1 [[ $(cat /cgroup/A/0/memory.current) -ge $(cat /cgroup/A/1/memory.current) ]] # A/0 should be consuming ~64mb [[ $(cat /cgroup/A/0/memory.current) -ge $x62mb ]] && [[ $(cat /cgroup/A/0/memory.current) -le $x66mb ]] # A should cumulatively be consuming ~96mb [[ $(cat /cgroup/A/memory.current) -ge $x94mb ]] && [[ $(cat /cgroup/A/memory.current) -le $x98mb ]] # Stop the stressors ps | grep stress | tr -s ' ' | cut -f 2 -d ' ' | xargs -I % kill % } teardown 1 setup for ((i=1;i<=$1;i++)); do printf "ITERATION $i of $1 - stress_test 0 1" stress_test 0 1 printf "\x1b[2K\r" printf "ITERATION $i of $1 - stress_test 1 0" stress_test 1 0 printf "\x1b[2K\r" printf "ITERATION $i of $1 - PASSED\n" done teardown 1 echo PASSED! 20:11:26@sjchrist-vm ? ~ $ memcg_low_test 10 Link: http://lkml.kernel.org/r/1496434412-21005-1-git-send-email-sean.j.christopherson@intel.com Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-06mm: memcontrol: per-lruvec stats infrastructureJohannes Weiner
lruvecs are at the intersection of the NUMA node and memcg, which is the scope for most paging activity. Introduce a convenient accounting infrastructure that maintains statistics per node, per memcg, and the lruvec itself. Then convert over accounting sites for statistics that are already tracked in both nodes and memcgs and can be easily switched. [hannes@cmpxchg.org: fix crash in the new cgroup stat keeping code] Link: http://lkml.kernel.org/r/20170531171450.GA10481@cmpxchg.org [hannes@cmpxchg.org: don't track uncharged pages at all Link: http://lkml.kernel.org/r/20170605175254.GA8547@cmpxchg.org [hannes@cmpxchg.org: add missing free_percpu()] Link: http://lkml.kernel.org/r/20170605175354.GB8547@cmpxchg.org [linux@roeck-us.net: hexagon: fix build error caused by include file order] Link: http://lkml.kernel.org/r/20170617153721.GA4382@roeck-us.net Link: http://lkml.kernel.org/r/20170530181724.27197-6-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-06mm: memcontrol: use the node-native slab memory countersJohannes Weiner
Now that the slab counters are moved from the zone to the node level we can drop the private memcg node stats and use the official ones. Link: http://lkml.kernel.org/r/20170530181724.27197-4-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-06mm/oom_kill: count global and memory cgroup oom killsKonstantin Khlebnikov
Show count of oom killer invocations in /proc/vmstat and count of processes killed in memory cgroup in knob "memory.events" (in memory.oom_control for v1 cgroup). Also describe difference between "oom" and "oom_kill" in memory cgroup documentation. Currently oom in memory cgroup kills tasks iff shortage has happened inside page fault. These counters helps in monitoring oom kills - for now the only way is grepping for magic words in kernel log. [akpm@linux-foundation.org: fix for mem_cgroup_count_vm_event() rename] [akpm@linux-foundation.org: fix comment, per Konstantin] Link: http://lkml.kernel.org/r/149570810989.203600.9492483715840752937.stgit@buzz Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Roman Guschin <guroan@gmail.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-06mm: per-cgroup memory reclaim statsRoman Gushchin
Track the following reclaim counters for every memory cgroup: PGREFILL, PGSCAN, PGSTEAL, PGACTIVATE, PGDEACTIVATE, PGLAZYFREE and PGLAZYFREED. These values are exposed using the memory.stats interface of cgroup v2. The meaning of each value is the same as for global counters, available using /proc/vmstat. Also, for consistency, rename mem_cgroup_count_vm_event() to count_memcg_event_mm(). Link: http://lkml.kernel.org/r/1494530183-30808-1-git-send-email-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-06mm, THP, swap: delay splitting THP during swap outHuang Ying
Patch series "THP swap: Delay splitting THP during swapping out", v11. This patchset is to optimize the performance of Transparent Huge Page (THP) swap. Recently, the performance of the storage devices improved so fast that we cannot saturate the disk bandwidth with single logical CPU when do page swap out even on a high-end server machine. Because the performance of the storage device improved faster than that of single logical CPU. And it seems that the trend will not change in the near future. On the other hand, the THP becomes more and more popular because of increased memory size. So it becomes necessary to optimize THP swap performance. The advantages of the THP swap support include: - Batch the swap operations for the THP to reduce lock acquiring/releasing, including allocating/freeing the swap space, adding/deleting to/from the swap cache, and writing/reading the swap space, etc. This will help improve the performance of the THP swap. - The THP swap space read/write will be 2M sequential IO. It is particularly helpful for the swap read, which are usually 4k random IO. This will improve the performance of the THP swap too. - It will help the memory fragmentation, especially when the THP is heavily used by the applications. The 2M continuous pages will be free up after THP swapping out. - It will improve the THP utilization on the system with the swap turned on. Because the speed for khugepaged to collapse the normal pages into the THP is quite slow. After the THP is split during the swapping out, it will take quite long time for the normal pages to collapse back into the THP after being swapped in. The high THP utilization helps the efficiency of the page based memory management too. There are some concerns regarding THP swap in, mainly because possible enlarged read/write IO size (for swap in/out) may put more overhead on the storage device. To deal with that, the THP swap in should be turned on only when necessary. For example, it can be selected via "always/never/madvise" logic, to be turned on globally, turned off globally, or turned on only for VMA with MADV_HUGEPAGE, etc. This patchset is the first step for the THP swap support. The plan is to delay splitting THP step by step, finally avoid splitting THP during the THP swapping out and swap out/in the THP as a whole. As the first step, in this patchset, the splitting huge page is delayed from almost the first step of swapping out to after allocating the swap space for the THP and adding the THP into the swap cache. This will reduce lock acquiring/releasing for the locks used for the swap cache management. With the patchset, the swap out throughput improves 15.5% (from about 3.73GB/s to about 4.31GB/s) in the vm-scalability swap-w-seq test case with 8 processes. The test is done on a Xeon E5 v3 system. The swap device used is a RAM simulated PMEM (persistent memory) device. To test the sequential swapping out, the test case creates 8 processes, which sequentially allocate and write to the anonymous pages until the RAM and part of the swap device is used up. This patch (of 5): In this patch, splitting huge page is delayed from almost the first step of swapping out to after allocating the swap space for the THP (Transparent Huge Page) and adding the THP into the swap cache. This will batch the corresponding operation, thus improve THP swap out throughput. This is the first step for the THP swap optimization. The plan is to delay splitting the THP step by step and avoid splitting the THP finally. In this patch, one swap cluster is used to hold the contents of each THP swapped out. So, the size of the swap cluster is changed to that of the THP (Transparent Huge Page) on x86_64 architecture (512). For other architectures which want such THP swap optimization, ARCH_USES_THP_SWAP_CLUSTER needs to be selected in the Kconfig file for the architecture. In effect, this will enlarge swap cluster size by 2 times on x86_64. Which may make it harder to find a free cluster when the swap space becomes fragmented. So that, this may reduce the continuous swap space allocation and sequential write in theory. The performance test in 0day shows no regressions caused by this. In the future of THP swap optimization, some information of the swapped out THP (such as compound map count) will be recorded in the swap_cluster_info data structure. The mem cgroup swap accounting functions are enhanced to support charge or uncharge a swap cluster backing a THP as a whole. The swap cluster allocate/free functions are added to allocate/free a swap cluster for a THP. A fair simple algorithm is used for swap cluster allocation, that is, only the first swap device in priority list will be tried to allocate the swap cluster. The function will fail if the trying is not successful, and the caller will fallback to allocate a single swap slot instead. This works good enough for normal cases. If the difference of the number of the free swap clusters among multiple swap devices is significant, it is possible that some THPs are split earlier than necessary. For example, this could be caused by big size difference among multiple swap devices. The swap cache functions is enhanced to support add/delete THP to/from the swap cache as a set of (HPAGE_PMD_NR) sub-pages. This may be enhanced in the future with multi-order radix tree. But because we will split the THP soon during swapping out, that optimization doesn't make much sense for this first step. The THP splitting functions are enhanced to support to split THP in swap cache during swapping out. The page lock will be held during allocating the swap cluster, adding the THP into the swap cache and splitting the THP. So in the code path other than swapping out, if the THP need to be split, the PageSwapCache(THP) will be always false. The swap cluster is only available for SSD, so the THP swap optimization in this patchset has no effect for HDD. [ying.huang@intel.com: fix two issues in THP optimize patch] Link: http://lkml.kernel.org/r/87k25ed8zo.fsf@yhuang-dev.intel.com [hannes@cmpxchg.org: extensive cleanups and simplifications, reduce code size] Link: http://lkml.kernel.org/r/20170515112522.32457-2-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Andrew Morton <akpm@linux-foundation.org> [for config option] Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> [for changes in huge_memory.c and huge_mm.h] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-20sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list namingIngo Molnar
So I've noticed a number of instances where it was not obvious from the code whether ->task_list was for a wait-queue head or a wait-queue entry. Furthermore, there's a number of wait-queue users where the lists are not for 'tasks' but other entities (poll tables, etc.), in which case the 'task_list' name is actively confusing. To clear this all up, name the wait-queue head and entry list structure fields unambiguously: struct wait_queue_head::task_list => ::head struct wait_queue_entry::task_list => ::entry For example, this code: rqw->wait.task_list.next != &wait->task_list ... is was pretty unclear (to me) what it's doing, while now it's written this way: rqw->wait.head.next != &wait->entry ... which makes it pretty clear that we are iterating a list until we see the head. Other examples are: list_for_each_entry_safe(pos, next, &x->task_list, task_list) { list_for_each_entry(wq, &fence->wait.task_list, task_list) { ... where it's unclear (to me) what we are iterating, and during review it's hard to tell whether it's trying to walk a wait-queue entry (which would be a bug), while now it's written as: list_for_each_entry_safe(pos, next, &x->head, entry) { list_for_each_entry(wq, &fence->wait.head, entry) { Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-20sched/wait: Rename wait_queue_t => wait_queue_entry_tIngo Molnar
Rename: wait_queue_t => wait_queue_entry_t 'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue", but in reality it's a queue *entry*. The 'real' queue is the wait queue head, which had to carry the name. Start sorting this out by renaming it to 'wait_queue_entry_t'. This also allows the real structure name 'struct __wait_queue' to lose its double underscore and become 'struct wait_queue_entry', which is the more canonical nomenclature for such data types. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-12hwpoison, memcg: forcibly uncharge LRU pagesMichal Hocko
Laurent Dufour has noticed that hwpoinsoned pages are kept charged. In his particular case he has hit a bad_page("page still charged to cgroup") when onlining a hwpoison page. While this looks like something that shouldn't happen in the first place because onlining hwpages and returning them to the page allocator makes only little sense it shows a real problem. hwpoison pages do not get freed usually so we do not uncharge them (at least not since commit 0a31bc97c80c ("mm: memcontrol: rewrite uncharge API")). Each charge pins memcg (since e8ea14cc6ead ("mm: memcontrol: take a css reference for each charged page")) as well and so the mem_cgroup and the associated state will never go away. Fix this leak by forcibly uncharging a LRU hwpoisoned page in delete_from_lru_cache(). We also have to tweak uncharge_list because it cannot rely on zero ref count for these pages. [akpm@linux-foundation.org: coding-style fixes] Fixes: 0a31bc97c80c ("mm: memcontrol: rewrite uncharge API") Link: http://lkml.kernel.org/r/20170502185507.GB19165@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Reviewed-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-03mm: memcontrol: use node page state naming scheme for memcgJohannes Weiner
The memory controllers stat function names are awkwardly long and arbitrarily different from the zone and node stat functions. The current interface is named: mem_cgroup_read_stat() mem_cgroup_update_stat() mem_cgroup_inc_stat() mem_cgroup_dec_stat() mem_cgroup_update_page_stat() mem_cgroup_inc_page_stat() mem_cgroup_dec_page_stat() This patch renames it to match the corresponding node stat functions: memcg_page_state() [node_page_state()] mod_memcg_state() [mod_node_state()] inc_memcg_state() [inc_node_state()] dec_memcg_state() [dec_node_state()] mod_memcg_page_state() [mod_node_page_state()] inc_memcg_page_state() [inc_node_page_state()] dec_memcg_page_state() [dec_node_page_state()] Link: http://lkml.kernel.org/r/20170404220148.28338-4-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-03mm: memcontrol: re-use node VM page state enumJohannes Weiner
The current duplication is a high-maintenance mess, and it's painful to add new items or query memcg state from the rest of the VM. This increases the size of the stat array marginally, but we should aim to track all these stats on a per-cgroup level anyway. Link: http://lkml.kernel.org/r/20170404220148.28338-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-03mm: memcontrol: re-use global VM event enumJohannes Weiner
The current duplication is a high-maintenance mess, and it's painful to add new items. This increases the size of the event array, but we'll eventually want most of the VM events tracked on a per-cgroup basis anyway. Link: http://lkml.kernel.org/r/20170404220148.28338-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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