Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762290AbXEPPjv (ORCPT ); Wed, 16 May 2007 11:39:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760905AbXEPPjm (ORCPT ); Wed, 16 May 2007 11:39:42 -0400 Received: from ozlabs.org ([203.10.76.45]:53197 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756659AbXEPPjl (ORCPT ); Wed, 16 May 2007 11:39:41 -0400 Date: Wed, 16 May 2007 10:37:03 -0500 From: Anton Blanchard To: Hugh Dickins Cc: Christoph Lameter , Andrew Morton , Badari Pulavarty , netdev@vger.kernel.org, lkml , sfr@canb.auug.org.au, ak@suse.de Subject: Re: select(0, ..) is valid ? Message-ID: <20070516153703.GA26912@kryten> References: <1179250159.2836.117.camel@dyn9047017100.beaverton.ibm.com> <20070515104453.f901e91f.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 871 Lines: 21 Hi Hugh, > It's interesting that compat_core_sys_select() shows this kmalloc(0) > failure but core_sys_select() does not. That's because core_sys_select() > avoids kmalloc by using a buffer on the stack for small allocations (and > 0 sure is small). Shouldn't compat_core_sys_select() do just the same? > Or is SLUB going to be so efficient that doing so is a waste of time? Nice catch, the original optimisation from Andi is: http://git.kernel.org/git-new/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=70674f95c0a2ea694d5c39f4e514f538a09be36f And I think it makes sense for the compat code to do it too. Anton - 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/