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authorJia He <hejianet@gmail.com>2016-08-02 14:02:31 -0700
committerSasha Levin <alexander.levin@verizon.com>2016-08-19 23:08:33 -0400
commit4ef5c9aa794064d8dd5bbe82921e26befb97a7c7 (patch)
tree8be7e2f9c3b367464020865551b3f0db4a26df9d /mm
parent834ced1a13bdf510eae34d08bae1f1ae49b33141 (diff)
mm/hugetlb: avoid soft lockup in set_max_huge_pages()
[ Upstream commit 649920c6ab93429b94bc7c1aa7c0e8395351be32 ] 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> 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: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'mm')
-rw-r--r--mm/hugetlb.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 9d724c0383d2..88b472bec71d 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1756,6 +1756,10 @@ 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