Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758788AbbLBQGQ (ORCPT ); Wed, 2 Dec 2015 11:06:16 -0500 Received: from resqmta-ch2-08v.sys.comcast.net ([69.252.207.40]:40739 "EHLO resqmta-ch2-08v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750772AbbLBQGP (ORCPT ); Wed, 2 Dec 2015 11:06:15 -0500 Date: Wed, 2 Dec 2015 10:06:13 -0600 (CST) From: Christoph Lameter X-X-Sender: cl@east.gentwo.org To: Geliang Tang cc: Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] mm/slab: use list_{empty_careful,last_entry} in drain_freelist In-Reply-To: <670c0018e0e4f44d6e788423b35e2c32ccf6c1e2.1449070964.git.geliangtang@163.com> Message-ID: References: <7e551749f5a50cef15a33320d6d33b9d0b0986bd.1449070964.git.geliangtang@163.com> <670c0018e0e4f44d6e788423b35e2c32ccf6c1e2.1449070964.git.geliangtang@163.com> Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1168 Lines: 35 On Wed, 2 Dec 2015, Geliang Tang wrote: > diff --git a/mm/slab.c b/mm/slab.c > index 5d5aa3b..1a7d91c 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -2362,21 +2362,14 @@ static void drain_cpu_caches(struct kmem_cache *cachep) > static int drain_freelist(struct kmem_cache *cache, > struct kmem_cache_node *n, int tofree) > { > - struct list_head *p; > int nr_freed; > struct page *page; > > nr_freed = 0; > - while (nr_freed < tofree && !list_empty(&n->slabs_free)) { > + while (nr_freed < tofree && !list_empty_careful(&n->slabs_free)) { > > spin_lock_irq(&n->list_lock); > - p = n->slabs_free.prev; > - if (p == &n->slabs_free) { > - spin_unlock_irq(&n->list_lock); > - goto out; > - } > - > - page = list_entry(p, struct page, lru); > + page = list_last_entry(&n->slabs_free, struct page, lru); This is safe? Process could be rescheduled and lots of things could happen before disabling irqs. -- 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/