From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933129Ab0JZM2k (ORCPT ); Tue, 26 Oct 2010 08:28:40 -0400 Received: from hera.kernel.org ([140.211.167.34]:52940 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932478Ab0JZM2j (ORCPT ); Tue, 26 Oct 2010 08:28:39 -0400 Message-ID: <4CC6C941.2080003@kernel.org> Date: Tue, 26 Oct 2010 14:27:45 +0200 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.11) Gecko/20101013 Lightning/1.0b2 Thunderbird/3.1.5 MIME-Version: 1.0 To: David Howells CC: torvalds@osdl.org, akpm@linux-foundation.org, linux-am33-list@redhat.com, linux-kernel@vger.kernel.org, Akira Takeuchi , Mark Salter Subject: Re: [PATCH] MN10300: Fix the PERCPU() alignment to allow for workqueues References: <4CC69B22.2050708@kernel.org> <20101025224111.7798.38960.stgit@warthog.procyon.org.uk> <12101.1288088542@redhat.com> <4CC6C62F.1000804@kernel.org> In-Reply-To: <4CC6C62F.1000804@kernel.org> X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Tue, 26 Oct 2010 12:27:47 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/26/2010 02:14 PM, Tejun Heo wrote: >>> That said, I think it might be better to just remove the alignment parameter >>> from the macro and force align to PAGE_SIZE. >> >> That's not necessarily good. Two arches to note: >> >> arch/x86/kernel/vmlinux.lds.S: PERCPU(THREAD_SIZE) > > I don't think the current percpu allocator honors alignment larger > than PAGE_SIZE no matter how large the alignment for the percpu output > section is. I'll look into it deeper but I think we might just have > been lucky and the alignment somehow didn't bite us yet. The only > user of THREAD_SIZE mask at this point seems to be cpu_init(). Maybe > we can remove this requirement. I'll look into it. Okay, this was added by commit fe8e0c2 in this merge window. It's broken and needs to be reverted. I'll send a patch to revert it. Thanks. -- tejun