From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750945AbWAXOz0 (ORCPT ); Tue, 24 Jan 2006 09:55:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964987AbWAXOzZ (ORCPT ); Tue, 24 Jan 2006 09:55:25 -0500 Received: from ns2.suse.de ([195.135.220.15]:9966 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S1750945AbWAXOzZ (ORCPT ); Tue, 24 Jan 2006 09:55:25 -0500 From: Andi Kleen To: Eric Dumazet Subject: Re: [PATCH] [SMP] reduce size of percpudata, and make sure per_cpu(object, not_possible_cpu) cause an invalid memory reference Date: Tue, 24 Jan 2006 15:53:50 +0100 User-Agent: KMail/1.8 Cc: Andrew Morton , Jan Beulich , linux-kernel@vger.kernel.org, shai@scalex86.org, kiran@scalex86.org, pravins@calsoftinc.com References: <43CE4C98.76F0.0078.0@novell.com> <20060124005806.7e9ab02e.akpm@osdl.org> <43D63DB5.3010601@cosmosbay.com> In-Reply-To: <43D63DB5.3010601@cosmosbay.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200601241553.50874.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 24 January 2006 15:46, Eric Dumazet wrote: > As some architectures (x86_64) are now allocating cpudata only on possible > cpus, we (kernel developers on x86 machines) should make sure that x86 does > a similar thing to find bugs. This is important that this patch has some > exposure in -mm for some time, some places must now use : The for_each_cpu changes should be actually merged ASAP because x86-64 needs them (or maybe i should back out that change until the kernel is ready?) But it really saves a lot of memory - several MB on a distro kernel which is compiled with NR_CPUS==128. -Andi