From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f198.google.com (mail-io0-f198.google.com [209.85.223.198]) by kanga.kvack.org (Postfix) with ESMTP id A58846B0253 for ; Tue, 26 Jul 2016 11:44:43 -0400 (EDT) Received: by mail-io0-f198.google.com with SMTP id u25so36242083ioi.1 for ; Tue, 26 Jul 2016 08:44:43 -0700 (PDT) Received: from mail-io0-x243.google.com (mail-io0-x243.google.com. [2607:f8b0:4001:c06::243]) by mx.google.com with ESMTPS id v72si1938803ioi.97.2016.07.26.08.44.43 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Jul 2016 08:44:43 -0700 (PDT) Received: by mail-io0-x243.google.com with SMTP id q83so2178234iod.2 for ; Tue, 26 Jul 2016 08:44:43 -0700 (PDT) From: Jia He Subject: [RFC PATCH] mm/hugetlb: Avoid soft lockup in set_max_huge_pages() Date: Tue, 26 Jul 2016 23:44:28 +0800 Message-Id: <1469547868-9814-1-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 large memory(32TB) powerpc servers, we watched several soft lockup 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 lockup. I thouhgt it is safe to call cond_resched() because alloc_fresh_gigantic_page and alloc_fresh_huge_page are 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 --- mm/hugetlb.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index addfe4ac..d51759d 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1146,6 +1146,10 @@ static int alloc_fresh_gigantic_page(struct hstate *h, for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { page = alloc_fresh_gigantic_page_node(h, node); + + /* yield cpu */ + cond_resched(); + if (page) return 1; } @@ -1381,6 +1385,10 @@ static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed) for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { page = alloc_fresh_huge_page_node(h, node); + + /* yield cpu */ + cond_resched(); + if (page) { ret = 1; break; -- 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