From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932465AbcHHTgW (ORCPT ); Mon, 8 Aug 2016 15:36:22 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36551 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932329AbcHHTSL (ORCPT ); Mon, 8 Aug 2016 15:18:11 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mel Gorman , Marcin Wojtas , Vlastimil Babka , Michal Hocko , Andrew Morton , Linus Torvalds Subject: [PATCH 4.6 08/96] mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask Date: Mon, 8 Aug 2016 21:10:31 +0200 Message-Id: <20160808180244.270429707@linuxfoundation.org> X-Mailer: git-send-email 2.9.2 In-Reply-To: <20160808180243.898163389@linuxfoundation.org> References: <20160808180243.898163389@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mel Gorman commit e838a45f9392a5bd2be1cd3ab0b16ae85857461c upstream. Commit d0164adc89f6 ("mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd") modified __GFP_WAIT to explicitly identify the difference between atomic callers and those that were unwilling to sleep. Later the definition was removed entirely. The GFP_RECLAIM_MASK is the set of flags that affect watermark checking and reclaim behaviour but __GFP_ATOMIC was never added. Without it, atomic users of the slab allocator strip the __GFP_ATOMIC flag and cannot access the page allocator atomic reserves. This patch addresses the problem. The user-visible impact depends on the workload but potentially atomic allocations unnecessarily fail without this path. Link: http://lkml.kernel.org/r/20160610093832.GK2527@techsingularity.net Signed-off-by: Mel Gorman Reported-by: Marcin Wojtas Acked-by: Vlastimil Babka Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/internal.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/internal.h +++ b/mm/internal.h @@ -24,7 +24,8 @@ */ #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\ __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\ - __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC) + __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\ + __GFP_ATOMIC) /* The GFP flags allowed during early boot */ #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))