From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: Re: [PATCH] slab+slob: dup name string Date: Wed, 23 May 2012 18:50:57 +0400 Message-ID: <4FBCF951.3040105@parallels.com> References: <1337613539-29108-1-git-send-email-glommer@parallels.com> <4FBBAE95.6080608@parallels.com> <1337773595.3013.15.camel@dabdike.int.hansenpartnership.com> <4FBCD328.6060406@parallels.com> <1337775878.3013.16.camel@dabdike.int.hansenpartnership.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Christoph Lameter Cc: James Bottomley , David Rientjes , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Pekka Enberg On 05/23/2012 06:48 PM, Christoph Lameter wrote: > On Wed, 23 May 2012, James Bottomley wrote: > >>>> So, why not simply patch slab to rely on the string lifetime being the >>>> cache lifetime (or beyond) and therefore not having it take a copy? > > Well thats they way it was for a long time. There must be some reason that > someone started to add this copying business.... Pekka? > The question is less why we added, but rather why we're keeping. Of course reasoning about why it was added helps (so let's try to determine that), but so far the only reasonably strong argument in favor of keeping it was robustness. But given that a lot of systems still uses SLAB, and we have no record of bugs due to dangling name pointers, this might very well be overzealousness on our part. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx157.postini.com [74.125.245.157]) by kanga.kvack.org (Postfix) with SMTP id 4E7DC6B0083 for ; Wed, 23 May 2012 10:53:01 -0400 (EDT) Message-ID: <4FBCF951.3040105@parallels.com> Date: Wed, 23 May 2012 18:50:57 +0400 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [PATCH] slab+slob: dup name string References: <1337613539-29108-1-git-send-email-glommer@parallels.com> <4FBBAE95.6080608@parallels.com> <1337773595.3013.15.camel@dabdike.int.hansenpartnership.com> <4FBCD328.6060406@parallels.com> <1337775878.3013.16.camel@dabdike.int.hansenpartnership.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: James Bottomley , David Rientjes , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, Pekka Enberg On 05/23/2012 06:48 PM, Christoph Lameter wrote: > On Wed, 23 May 2012, James Bottomley wrote: > >>>> So, why not simply patch slab to rely on the string lifetime being the >>>> cache lifetime (or beyond) and therefore not having it take a copy? > > Well thats they way it was for a long time. There must be some reason that > someone started to add this copying business.... Pekka? > The question is less why we added, but rather why we're keeping. Of course reasoning about why it was added helps (so let's try to determine that), but so far the only reasonably strong argument in favor of keeping it was robustness. But given that a lot of systems still uses SLAB, and we have no record of bugs due to dangling name pointers, this might very well be overzealousness on our part. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933436Ab2EWOxC (ORCPT ); Wed, 23 May 2012 10:53:02 -0400 Received: from mx2.parallels.com ([64.131.90.16]:55296 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754119Ab2EWOxA (ORCPT ); Wed, 23 May 2012 10:53:00 -0400 Message-ID: <4FBCF951.3040105@parallels.com> Date: Wed, 23 May 2012 18:50:57 +0400 From: Glauber Costa User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.1) Gecko/20120216 Thunderbird/10.0.1 MIME-Version: 1.0 To: Christoph Lameter CC: James Bottomley , David Rientjes , , , , Pekka Enberg Subject: Re: [PATCH] slab+slob: dup name string References: <1337613539-29108-1-git-send-email-glommer@parallels.com> <4FBBAE95.6080608@parallels.com> <1337773595.3013.15.camel@dabdike.int.hansenpartnership.com> <4FBCD328.6060406@parallels.com> <1337775878.3013.16.camel@dabdike.int.hansenpartnership.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/23/2012 06:48 PM, Christoph Lameter wrote: > On Wed, 23 May 2012, James Bottomley wrote: > >>>> So, why not simply patch slab to rely on the string lifetime being the >>>> cache lifetime (or beyond) and therefore not having it take a copy? > > Well thats they way it was for a long time. There must be some reason that > someone started to add this copying business.... Pekka? > The question is less why we added, but rather why we're keeping. Of course reasoning about why it was added helps (so let's try to determine that), but so far the only reasonably strong argument in favor of keeping it was robustness. But given that a lot of systems still uses SLAB, and we have no record of bugs due to dangling name pointers, this might very well be overzealousness on our part.