From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:34460 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752483AbcHRM4y (ORCPT ); Thu, 18 Aug 2016 08:56:54 -0400 Subject: Patch "mm/hugetlb: avoid soft lockup in set_max_huge_pages()" has been added to the 4.7-stable tree To: hejianet@gmail.com, akpm@linux-foundation.org, dave.hansen@linux.intel.com, gregkh@linuxfoundation.org, kirill.shutemov@linux.intel.com, mhocko@suse.com, mike.kravetz@oracle.com, n-horiguchi@ah.jp.nec.com, paul.gortmaker@windriver.com, torvalds@linux-foundation.org Cc: , From: Date: Thu, 18 Aug 2016 14:45:32 +0200 Message-ID: <147152433232231@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled mm/hugetlb: avoid soft lockup in set_max_huge_pages() to the 4.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mm-hugetlb-avoid-soft-lockup-in-set_max_huge_pages.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 649920c6ab93429b94bc7c1aa7c0e8395351be32 Mon Sep 17 00:00:00 2001 From: Jia He Date: Tue, 2 Aug 2016 14:02:31 -0700 Subject: mm/hugetlb: avoid soft lockup in set_max_huge_pages() From: Jia He 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 Reviewed-by: Naoya Horiguchi Acked-by: Michal Hocko Acked-by: Dave Hansen Cc: Mike Kravetz Cc: "Kirill A. Shutemov" Cc: Paul Gortmaker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/hugetlb.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2214,6 +2214,10 @@ 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 Patches currently in stable-queue which might be from hejianet@gmail.com are queue-4.7/mm-hugetlb-avoid-soft-lockup-in-set_max_huge_pages.patch