Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964981AbVITMGO (ORCPT ); Tue, 20 Sep 2005 08:06:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964982AbVITMGO (ORCPT ); Tue, 20 Sep 2005 08:06:14 -0400 Received: from omx1-ext.sgi.com ([192.48.179.11]:467 "EHLO omx1.americas.sgi.com") by vger.kernel.org with ESMTP id S964981AbVITMGO (ORCPT ); Tue, 20 Sep 2005 08:06:14 -0400 Date: Tue, 20 Sep 2005 07:05:23 -0500 From: Robin Holt To: Paul Jackson Cc: zippel@linux-m68k.org, akpm@osdl.org, torvalds@osdl.org, Simon.Derr@bull.net, linux-kernel@vger.kernel.org, nikita@clusterfs.com Subject: Re: [PATCH] cpuset semaphore depth check optimize Message-ID: <20050920120523.GC21435@lnx-holt.americas.sgi.com> References: <20050912075155.3854b6e3.pj@sgi.com> <20050912153135.3812d8e2.pj@sgi.com> <20050913103724.19ac5efa.pj@sgi.com> <20050914124642.1b19dd73.pj@sgi.com> <20050915104535.6058bbda.pj@sgi.com> <20050920005743.4ea5f224.pj@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050920005743.4ea5f224.pj@sgi.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1278 Lines: 41 Paul, Can you give a _short_ explanation of why notify_on_release is essential? Could the intent be accomplished with something like destroy on exit which then goes through and does the remove of shildren and finally removes the cpuset? If we can agree on that, then the exit path becomes if (atomic_dec_and_lock(¤t->cpuset.refcount)) { /* Code to remove children. */ } which no longer needs to call a usermode helper and is _FAR_ better in my personal biased opinion. Thanks, Robin PS: For reference, here is what /sbin/cpuset_release_agent looks like: [holt@attica:sbin] cat cpuset_release_agent #!/bin/sh # Do not modify this file /sbin/cpuset_release_agent. # # It is invoked directly from the kernel's call_usermodehelper() # routine, whenever the last user of cpuset goes away, if that # cpuset had its 'notify_on_release' option set to '1'. This # cpuset_release_agent script is responsible for removing the # abandoned cpuset, whose cpuset file system path is passed # in argv[1]. rmdir /dev/cpuset/$1 - 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/