Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753483AbYKXWrq (ORCPT ); Mon, 24 Nov 2008 17:47:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753372AbYKXWrf (ORCPT ); Mon, 24 Nov 2008 17:47:35 -0500 Received: from courier.cs.helsinki.fi ([128.214.9.1]:52370 "EHLO mail.cs.helsinki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753851AbYKXWre (ORCPT ); Mon, 24 Nov 2008 17:47:34 -0500 Date: Tue, 25 Nov 2008 00:47:33 +0200 (EET) From: Pekka J Enberg To: Miklos Szeredi cc: linux-mm@kvack.org, cl@linux-foundation.org, david@fromorbit.com, peterz@infradead.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] slab: __GFP_NOWARN not being propagated from mempool_alloc() In-Reply-To: Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2345 Lines: 64 On Mon, 24 Nov 2008, Miklos Szeredi wrote: > We see page allocation failure warnings on the mempool_alloc() path. > See this lkml posting for example: > > http://lkml.org/lkml/2008/10/27/100 > > The cause is that on NUMA, alloc_slabmgmt() clears __GFP_NOWARN, > together with __GFP_THISNODE and __GFP_NORETRY. But AFAICS it really > only wants to clear __GFP_THISNODE. > > Does this patch looks good? Yes, it does but looking at mm/slab.c history I think we want something like the following instead. Christoph? P.S. First one to test it gets a fabulous prize of a Tested-by tag in the patch description! How cool is that? Pekka >From 717b2d7bd2398e948d1dfbd2e83bd6a8403b68da Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Tue, 25 Nov 2008 00:33:28 +0200 Subject: [PATCH] slab: remove GFP_THISNODE clearing from alloc_slabmgmt() Commit 6cb062296f73e74768cca2f3eaf90deac54de02d ("Categorize GFP flags") left one call-site in alloc_slabmgmt() to clear GFP_THISNODE instead of GFP_CONSTRAINT_MASK. Unfortunately, that ends up clearing __GFP_NOWARN and __GFP_NORETRY as well which is not what we want. As the only caller of alloc_slabmgmt() already clears GFP_CONSTRAINT_MASK before passing local_flags to it, we can just remove the clearing of GFP_THISNODE. This patch should fix spurious page allocation failure warnings on the mempool_alloc() path. See the following URL for an example: http://lkml.org/lkml/2008/10/27/100 Reported-by: Miklos Szeredi Signed-off-by: Pekka Enberg --- mm/slab.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 918f04f..98d3024 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2608,7 +2608,7 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, if (OFF_SLAB(cachep)) { /* Slab management obj is off-slab. */ slabp = kmem_cache_alloc_node(cachep->slabp_cache, - local_flags & ~GFP_THISNODE, nodeid); + local_flags, nodeid); if (!slabp) return NULL; } else { -- 1.5.6.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/