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authorLiu Zixian <liuzixian4@huawei.com>2021-09-09 04:10:05 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-09 04:45:53 +0300
commit13db8c50477d83ad3e3b9b0ae247e5cd833a7ae4 (patch)
tree0fe230614629425aaff4d127426bfed9501f9cef /kernel
parent4b42fb213678d2b6a9eeea92a9be200f23e49583 (diff)
downloadlinux-13db8c50477d83ad3e3b9b0ae247e5cd833a7ae4.tar.xz
mm/hugetlb: initialize hugetlb_usage in mm_init
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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/fork.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index ff5be23800af..38681ad44c76 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1063,6 +1063,7 @@ 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;