diff options
| author | Mike Kravetz <mike.kravetz@oracle.com> | 2020-11-01 17:07:27 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-11-02 12:14:18 -0800 |
| commit | 79aa925bf239c234be8586780e482872dc4690dd (patch) | |
| tree | c7899dba5dfb86761617f67cc78ac4fe48039fce /mm/hugetlb.c | |
| parent | 46b1ee38b2ba1a9524c8e886ad078bd3ca40de2a (diff) | |
hugetlb_cgroup: fix reservation accounting
Michal Privoznik was using "free page reporting" in QEMU/virtio-balloon
with hugetlbfs and hit the warning below. QEMU with free page hinting
uses fallocate(FALLOC_FL_PUNCH_HOLE) to discard pages that are reported
as free by a VM. The reporting granularity is in pageblock granularity.
So when the guest reports 2M chunks, we fallocate(FALLOC_FL_PUNCH_HOLE)
one huge page in QEMU.
WARNING: CPU: 7 PID: 6636 at mm/page_counter.c:57 page_counter_uncharge+0x4b/0x50
Modules linked in: ...
CPU: 7 PID: 6636 Comm: qemu-system-x86 Not tainted 5.9.0 #137
Hardware name: Gigabyte Technology Co., Ltd. X570 AORUS PRO/X570 AORUS PRO, BIOS F21 07/31/2020
RIP: 0010:page_counter_uncharge+0x4b/0x50
...
Call Trace:
hugetlb_cgroup_uncharge_file_region+0x4b/0x80
region_del+0x1d3/0x300
hugetlb_unreserve_pages+0x39/0xb0
remove_inode_hugepages+0x1a8/0x3d0
hugetlbfs_fallocate+0x3c4/0x5c0
vfs_fallocate+0x146/0x290
__x64_sys_fallocate+0x3e/0x70
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Investigation of the issue uncovered bugs in hugetlb cgroup reservation
accounting. This patch addresses the found issues.
Fixes: 075a61d07a8e ("hugetlb_cgroup: add accounting for shared mappings")
Reported-by: Michal Privoznik <mprivozn@redhat.com>
Co-developed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: <stable@vger.kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Link: https://lkml.kernel.org/r/20201021204426.36069-1-mike.kravetz@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index fe76f8fd5a73..5a620f690911 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -648,6 +648,8 @@ retry: } del += t - f; + hugetlb_cgroup_uncharge_file_region( + resv, rg, t - f); /* New entry for end of split region */ nrg->from = t; @@ -660,9 +662,6 @@ retry: /* Original entry is trimmed */ rg->to = f; - hugetlb_cgroup_uncharge_file_region( - resv, rg, nrg->to - nrg->from); - list_add(&nrg->link, &rg->link); nrg = NULL; break; @@ -678,17 +677,17 @@ retry: } if (f <= rg->from) { /* Trim beginning of region */ - del += t - rg->from; - rg->from = t; - hugetlb_cgroup_uncharge_file_region(resv, rg, t - rg->from); - } else { /* Trim end of region */ - del += rg->to - f; - rg->to = f; + del += t - rg->from; + rg->from = t; + } else { /* Trim end of region */ hugetlb_cgroup_uncharge_file_region(resv, rg, rg->to - f); + + del += rg->to - f; + rg->to = f; } } @@ -2443,6 +2442,9 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, rsv_adjust = hugepage_subpool_put_pages(spool, 1); hugetlb_acct_memory(h, -rsv_adjust); + if (deferred_reserve) + hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), + pages_per_huge_page(h), page); } return page; |