Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932636AbZJAOKB (ORCPT ); Thu, 1 Oct 2009 10:10:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932591AbZJAOJ4 (ORCPT ); Thu, 1 Oct 2009 10:09:56 -0400 Received: from victor.provo.novell.com ([137.65.250.26]:35256 "EHLO victor.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932588AbZJAOJy (ORCPT ); Thu, 1 Oct 2009 10:09:54 -0400 From: Suresh Jayaraman To: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: netdev@vger.kernel.org, Neil Brown , Miklos Szeredi , Wouter Verhelst , Peter Zijlstra , trond.myklebust@fys.uio.no, Suresh Jayaraman Subject: [PATCH 30/31] Fix use of uninitialized variable in cache_grow() Date: Thu, 1 Oct 2009 19:40:57 +0530 Message-Id: <1254406257-16735-1-git-send-email-sjayaraman@suse.de> X-Mailer: git-send-email 1.6.0.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1526 Lines: 45 From: Miklos Szeredi This fixes a bug in reserve-slub.patch. If cache_grow() was called with objp != NULL then the 'reserve' local variable wasn't initialized. This resulted in ac->reserve being set to a rubbish value. Due to this in some circumstances huge amounts of slab pages were allocated (due to slab_force_alloc() returning true), which caused atomic page allocation failures and slowdown of the system. Signed-off-by: Miklos Szeredi Signed-off-by: Suresh Jayaraman --- mm/slab.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) Index: mmotm/mm/slab.c =================================================================== --- mmotm.orig/mm/slab.c +++ mmotm/mm/slab.c @@ -2760,7 +2760,7 @@ static int cache_grow(struct kmem_cache size_t offset; gfp_t local_flags; struct kmem_list3 *l3; - int reserve; + int reserve = -1; /* * Be lazy and only check for valid flags here, keeping it out of the @@ -2816,7 +2816,8 @@ static int cache_grow(struct kmem_cache if (local_flags & __GFP_WAIT) local_irq_disable(); check_irq_off(); - slab_set_reserve(cachep, reserve); + if (reserve != -1) + slab_set_reserve(cachep, reserve); spin_lock(&l3->list_lock); /* Make slab active. */ -- 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/