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| author | Jia He <hejianet@gmail.com> | 2016-08-02 14:02:31 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-20 18:11:01 +0200 |
| commit | f0d430ad5b94175a82e9e502a5683a4826f38e19 (patch) | |
| tree | 5425c97d7da779c498861eb1d2dd3ce92d41786d | |
| parent | 23278d6a4ae6295cbecb7b443633a84f3687c3f4 (diff) | |
| download | lwn-f0d430ad5b94175a82e9e502a5683a4826f38e19.tar.gz lwn-f0d430ad5b94175a82e9e502a5683a4826f38e19.zip | |
mm/hugetlb: avoid soft lockup in set_max_huge_pages()
commit 649920c6ab93429b94bc7c1aa7c0e8395351be32 upstream.
In powerpc servers with large memory(32TB), we watched several soft
lockups for hugepage under stress tests.
The call traces are as follows:
1.
get_page_from_freelist+0x2d8/0xd50
__alloc_pages_nodemask+0x180/0xc20
alloc_fresh_huge_page+0xb0/0x190
set_max_huge_pages+0x164/0x3b0
2.
prep_new_huge_page+0x5c/0x100
alloc_fresh_huge_page+0xc8/0x190
set_max_huge_pages+0x164/0x3b0
This patch fixes such soft lockups. It is safe to call cond_resched()
there because it is out of spin_lock/unlock section.
Link: http://lkml.kernel.org/r/1469674442-14848-1-git-send-email-hejianet@gmail.com
Signed-off-by: Jia He <hejianet@gmail.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
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>
| -rw-r--r-- | mm/hugetlb.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index addfe4accc07..d9ec1a5b37ff 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2214,6 +2214,10 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count, * and reducing the surplus. */ spin_unlock(&hugetlb_lock); + + /* yield cpu to avoid soft lockup */ + cond_resched(); + if (hstate_is_gigantic(h)) ret = alloc_fresh_gigantic_page(h, nodes_allowed); else |