Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757380AbZFOJIp (ORCPT ); Mon, 15 Jun 2009 05:08:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752497AbZFOJIi (ORCPT ); Mon, 15 Jun 2009 05:08:38 -0400 Received: from courier.cs.helsinki.fi ([128.214.9.1]:59274 "EHLO mail.cs.helsinki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752466AbZFOJIi (ORCPT ); Mon, 15 Jun 2009 05:08:38 -0400 Subject: Re: [GIT PULL v2] Early SLAB fixes for 2.6.31 From: Pekka Enberg To: Nick Piggin Cc: Heiko Carstens , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, cl@linux-foundation.org, kamezawa.hiroyu@jp.fujitsu.com, lizf@cn.fujitsu.com, mingo@elte.hu, yinghai@kernel.org, benh@kernel.crashing.org In-Reply-To: <20090615085209.GB30964@wotan.suse.de> References: <20090615081831.GA5411@osiris.boeblingen.de.ibm.com> <20090615082636.GA30964@wotan.suse.de> <1245054779.23207.6.camel@penberg-laptop> <20090615085209.GB30964@wotan.suse.de> Date: Mon, 15 Jun 2009 12:08:39 +0300 Message-Id: <1245056919.23207.7.camel@penberg-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 7bit X-Mailer: Evolution 2.24.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2503 Lines: 74 On Mon, 2009-06-15 at 10:52 +0200, Nick Piggin wrote: > > Furthermore, early boot cache sysfs setup is explicitly > > handled in slab_sysfs_init() so I think we need something like the patch > > below? > > I don't think so because keventd probably comes up before sysfs > still is ready (in this respect the existing pre-early-slab code > is probably still broken but just never done such early DMA > allocations). So it just makes sense to do it all via the slab_state > flag. > > Also, if you keep the deferred flag on there for early created > slabs, then the next sysfs_add_work will try to add it again > (after slab_sysfs_init already added it). > > Here > > --- > mm/slub.c | 17 ++++++++++++++--- > 1 file changed, 14 insertions(+), 3 deletions(-) > > Index: linux-2.6/mm/slub.c > =================================================================== > --- linux-2.6.orig/mm/slub.c > +++ linux-2.6/mm/slub.c > @@ -2596,6 +2596,7 @@ static noinline struct kmem_cache *dma_k > struct kmem_cache *s; > char *text; > size_t realsize; > + unsigned long slabflags; > > s = kmalloc_caches_dma[index]; > if (s) > @@ -2617,9 +2618,18 @@ static noinline struct kmem_cache *dma_k > (unsigned int)realsize); > s = kmalloc(kmem_size, flags & ~SLUB_DMA); > > + /* > + * Must defer sysfs creation to a workqueue because we don't know > + * what context we are called from. Before sysfs comes up, we don't > + * need to do anything because slab_sysfs_init will start by > + * adding all existing slabs to sysfs. > + */ > + slabflags = SLAB_CACHE_DMA; > + if (slab_state >= SYSFS) > + slabflags |= __SYSFS_ADD_DEFERRED; > + > if (!s || !text || !kmem_cache_open(s, flags, text, > - realsize, ARCH_KMALLOC_MINALIGN, > - SLAB_CACHE_DMA|__SYSFS_ADD_DEFERRED, NULL)) { > + realsize, ARCH_KMALLOC_MINALIGN, slabflags, NULL)) { > kfree(s); > kfree(text); > goto unlock_out; > @@ -2628,7 +2638,8 @@ static noinline struct kmem_cache *dma_k > list_add(&s->list, &slab_caches); > kmalloc_caches_dma[index] = s; > > - schedule_work(&sysfs_add_work); > + if (slab_state >= SYSFS) > + schedule_work(&sysfs_add_work); > > unlock_out: > up_write(&slub_lock); Looks good to me. Heiko, does it fix your case? Pekka -- 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/