Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754950AbZF3OVi (ORCPT ); Tue, 30 Jun 2009 10:21:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752840AbZF3OVa (ORCPT ); Tue, 30 Jun 2009 10:21:30 -0400 Received: from smtp3.ultrahosting.com ([74.213.175.254]:39587 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751735AbZF3OV3 (ORCPT ); Tue, 30 Jun 2009 10:21:29 -0400 Date: Tue, 30 Jun 2009 10:20:24 -0400 (EDT) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Pekka Enberg cc: paulmck@linux.vnet.ibm.com, Matt Mackall , linux-kernel@vger.kernel.org, linux-mm@kvack.org, jdb@comx.dk Subject: Re: [PATCH RFC] fix RCU-callback-after-kmem_cache_destroy problem in sl[aou]b In-Reply-To: <84144f020906292358j6517b599n471eed4e88781a78@mail.gmail.com> Message-ID: References: <20090625193137.GA16861@linux.vnet.ibm.com> <1246315553.21295.100.camel@calx> <1246320394.21295.105.camel@calx> <20090630060031.GL7070@linux.vnet.ibm.com> <84144f020906292358j6517b599n471eed4e88781a78@mail.gmail.com> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 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: 776 Lines: 18 On Tue, 30 Jun 2009, Pekka Enberg wrote: > I don't even claim to understand all the RCU details here but I don't > see why we should care about _kmem_cache_destroy()_ performance at > this level. Christoph, hmmm? Well it was surprising to me that kmem_cache_destroy() would perform rcu actions in the first place. RCU is usually handled externally and not within the slab allocator. The only reason that SLAB_DESTROY_BY_RCU exists is because the user cannot otherwise control the final release of memory to the page allocator. -- 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/