From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f70.google.com (mail-it0-f70.google.com [209.85.214.70]) by kanga.kvack.org (Postfix) with ESMTP id CFFB26B025F for ; Wed, 27 Jul 2016 22:54:17 -0400 (EDT) Received: by mail-it0-f70.google.com with SMTP id j124so41031806ith.1 for ; Wed, 27 Jul 2016 19:54:17 -0700 (PDT) Received: from mail-it0-x241.google.com (mail-it0-x241.google.com. [2607:f8b0:4001:c0b::241]) by mx.google.com with ESMTPS id h98si10205557iod.123.2016.07.27.19.54.16 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 Jul 2016 19:54:16 -0700 (PDT) Received: by mail-it0-x241.google.com with SMTP id f6so3997027ith.2 for ; Wed, 27 Jul 2016 19:54:16 -0700 (PDT) From: Jia He Subject: [PATCH V2] mm/hugetlb: Avoid soft lockup in set_max_huge_pages() Date: Thu, 28 Jul 2016 10:54:02 +0800 Message-Id: <1469674442-14848-1-git-send-email-hejianet@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Jia He , Andrew Morton , Naoya Horiguchi , Mike Kravetz , "Kirill A. Shutemov" , Michal Hocko , Dave Hansen , Paul Gortmaker In powerpc servers with large memory(32TB), we watched several soft lockups for hugepage under stress tests. The call trace 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 is to fix such soft lockups. It is safe to call cond_resched() there because it is out of spin_lock/unlock section. Signed-off-by: Jia He Cc: Andrew Morton Cc: Naoya Horiguchi Cc: Mike Kravetz Cc: "Kirill A. Shutemov" Cc: Michal Hocko Cc: Dave Hansen Cc: Paul Gortmaker --- Changes in V2: move cond_resched to a common calling site in set_max_huge_pages mm/hugetlb.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index abc1c5f..9284280 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2216,6 +2216,10 @@ 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 -- 2.5.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org