From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266143AbUFIWs5 (ORCPT ); Wed, 9 Jun 2004 18:48:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266201AbUFIWs4 (ORCPT ); Wed, 9 Jun 2004 18:48:56 -0400 Received: from mtvcafw.sgi.com ([192.48.171.6]:41149 "EHLO omx3.sgi.com") by vger.kernel.org with ESMTP id S266143AbUFIWsl (ORCPT ); Wed, 9 Jun 2004 18:48:41 -0400 Date: Wed, 9 Jun 2004 15:47:50 -0700 From: Paul Jackson To: Mikael Pettersson Cc: akpm@osdl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH][2.6.7-rc3-mm1] perfctr cpumask cleanup Message-Id: <20040609154750.241df741.pj@sgi.com> In-Reply-To: <200406092050.i59KoWoa000621@alkaid.it.uu.se> References: <200406092050.i59KoWoa000621@alkaid.it.uu.se> Organization: SGI X-Mailer: Sylpheed version 0.9.8 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Clean up perfctr/virtual by using the new cpus_andnot() operation Neat. Do you still need "tmp" ? Perhaps you could further add the following patch (untested, unbuilt, ...). This saves copies and stack space for one cpumask (that's 512 bits on my SN2 systems). Signed-off-by: Paul Jackson Index: 2.6.7-rc3-mm1/drivers/perfctr/virtual.c =================================================================== --- 2.6.7-rc3-mm1.orig/drivers/perfctr/virtual.c 2004-06-09 15:34:34.000000000 -0700 +++ 2.6.7-rc3-mm1/drivers/perfctr/virtual.c 2004-06-09 15:38:32.000000000 -0700 @@ -403,11 +403,10 @@ return -EFAULT; if (control.cpu_control.nractrs || control.cpu_control.nrictrs) { - cpumask_t tmp, old_mask, new_mask; + cpumask_t old_mask, new_mask; - tmp = perfctr_cpus_forbidden_mask; old_mask = tsk->cpus_allowed; - cpus_andnot(new_mask, old_mask, tmp); + cpus_andnot(new_mask, old_mask, perfctr_cpus_forbidden_mask); if (cpus_empty(new_mask)) return -EINVAL; -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.650.933.1373