From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:39310 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751114AbbDZJ4y (ORCPT ); Sun, 26 Apr 2015 05:56:54 -0400 Subject: Patch "mm: hwpoison: drop lru_add_drain_all() in __soft_offline_page()" has been added to the 3.14-stable tree To: n-horiguchi@ah.jp.nec.com, akpm@linux-foundation.org, andi@firstfloor.org, gong.chen@linux.intel.com, gregkh@linuxfoundation.org, stable@vger.kernel.org, tony.luck@intel.com, torvalds@linux-foundation.org Cc: , From: Date: Sun, 26 Apr 2015 11:56:51 +0200 Message-ID: <1430042211220252@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: hwpoison: drop lru_add_drain_all() in __soft_offline_page() to the 3.14-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-hwpoison-drop-lru_add_drain_all-in-__soft_offline_page.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 9ab3b598d2dfbdb0153ffa7e4b1456bbff59a25d Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Thu, 12 Feb 2015 15:00:25 -0800 Subject: mm: hwpoison: drop lru_add_drain_all() in __soft_offline_page() From: Naoya Horiguchi commit 9ab3b598d2dfbdb0153ffa7e4b1456bbff59a25d upstream. A race condition starts to be visible in recent mmotm, where a PG_hwpoison flag is set on a migration source page *before* it's back in buddy page poo= l. This is problematic because no page flag is supposed to be set when freeing (see __free_one_page().) So the user-visible effect of this race is that it could trigger the BUG_ON() when soft-offlining is called. The root cause is that we call lru_add_drain_all() to make sure that the page is in buddy, but that doesn't work because this function just schedule= s a work item and doesn't wait its completion. drain_all_pages() does drainin= g directly, so simply dropping lru_add_drain_all() solves this problem. [n-horiguchi@ah.jp.nec.com: resolve conflict to apply on v3.11.10] Fixes: f15bdfa802bf ("mm/memory-failure.c: fix memory leak in successful soft offlining") Signed-off-by: Naoya Horiguchi Cc: Andi Kleen Cc: Tony Luck Cc: Chen Gong Cc: [3.11+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/memory-failure.c | 2 -- 1 file changed, 2 deletions(-) --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1645,8 +1645,6 @@ static int __soft_offline_page(struct pa * setting PG_hwpoison. */ if (!is_free_buddy_page(page)) - lru_add_drain_all(); - if (!is_free_buddy_page(page)) drain_all_pages(); SetPageHWPoison(page); if (!is_free_buddy_page(page)) Patches currently in stable-queue which might be from n-horiguchi@ah.jp.nec.com are queue-3.14/mm-hwpoison-drop-lru_add_drain_all-in-__soft_offline_page.patch