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| author | Liu Zixian <liuzixian4@huawei.com> | 2021-09-08 18:10:05 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-22 12:26:37 +0200 |
| commit | 22b11dbbf94c59b41e99fd2a0c1b543ea18c6ba8 (patch) | |
| tree | bd9fb25d88bc7f4bee55038e36aa658a9102ec84 /kernel | |
| parent | 1dc6df795c9f341935d10520751e83be854d0831 (diff) | |
| download | linux-stable-22b11dbbf94c59b41e99fd2a0c1b543ea18c6ba8.tar.gz linux-stable-22b11dbbf94c59b41e99fd2a0c1b543ea18c6ba8.tar.bz2 linux-stable-22b11dbbf94c59b41e99fd2a0c1b543ea18c6ba8.zip | |
mm/hugetlb: initialize hugetlb_usage in mm_init
commit 13db8c50477d83ad3e3b9b0ae247e5cd833a7ae4 upstream.
After fork, the child process will get incorrect (2x) hugetlb_usage. If
a process uses 5 2MB hugetlb pages in an anonymous mapping,
HugetlbPages: 10240 kB
and then forks, the child will show,
HugetlbPages: 20480 kB
The reason for double the amount is because hugetlb_usage will be copied
from the parent and then increased when we copy page tables from parent
to child. Child will have 2x actual usage.
Fix this by adding hugetlb_count_init in mm_init.
Link: https://lkml.kernel.org/r/20210826071742.877-1-liuzixian4@huawei.com
Fixes: 5d317b2b6536 ("mm: hugetlb: proc: add HugetlbPages field to /proc/PID/status")
Signed-off-by: Liu Zixian <liuzixian4@huawei.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/fork.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 50f37d5afb32..cf2cebd214b9 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1028,6 +1028,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm->pmd_huge_pte = NULL; #endif mm_init_uprobes_state(mm); + hugetlb_count_init(mm); if (current->mm) { mm->flags = current->mm->flags & MMF_INIT_MASK; |