From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753313AbYG1Gfa (ORCPT ); Mon, 28 Jul 2008 02:35:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751567AbYG1GfW (ORCPT ); Mon, 28 Jul 2008 02:35:22 -0400 Received: from ozlabs.org ([203.10.76.45]:48592 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751236AbYG1GfW (ORCPT ); Mon, 28 Jul 2008 02:35:22 -0400 From: Rusty Russell To: Andrew Morton Subject: Re: [git pull] cpus4096 fixes Date: Mon, 28 Jul 2008 16:34:42 +1000 User-Agent: KMail/1.9.9 Cc: Linus Torvalds , Ingo Molnar , Linux Kernel Mailing List , Mike Travis References: <20080727190601.GA764@elte.hu> <200807281042.12860.rusty@rustcorp.com.au> <20080727200636.96da12d0.akpm@linux-foundation.org> In-Reply-To: <20080727200636.96da12d0.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200807281634.43036.rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 28 July 2008 13:06:36 Andrew Morton wrote: > On Mon, 28 Jul 2008 10:42:12 +1000 Rusty Russell wrote: > > The 4k CPU patches have been sliding in without review up until now. > > wot? This surprises you? I stumbled across the cpumask_of_cpu() bug because I happened to want it for stop_machine and read the damned code. But it lead me to the surrounding code, which is pretty questionable. An arch-specific map, rather than depending on NR_CPUS? Adding set_cpus_allowed_ptr() instead of changing set_cpus_allowed()? Macros which declare things and may or may not do an allocation/free? Finally a patch so horrifically ugly that it can't be ignored any more gets all the way to Linus. Overall, it seems like an attempt to sneak in gradual workarounds for cpumasks on the stack, rather than a coherent plan. I understand the temptation to avoid an "are we prepared to pay this price for large NR_CPUS?" discussion, but we need it anyway. And that's what I call "review". Rusty.