Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 098/138] mm/hugetlb: avoid soft lockup in set_max_huge_pages() | Date | Thu, 18 Aug 2016 15:58:28 +0200 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Jia He <hejianet@gmail.com>
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>
--- mm/hugetlb.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2170,6 +2170,10 @@ static unsigned long set_max_huge_pages( * 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
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