From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1945926AbXC3DyB (ORCPT ); Thu, 29 Mar 2007 23:54:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1945929AbXC3DyB (ORCPT ); Thu, 29 Mar 2007 23:54:01 -0400 Received: from an-out-0708.google.com ([209.85.132.241]:23720 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1945926AbXC3DyA (ORCPT ); Thu, 29 Mar 2007 23:54:00 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=G8J/CIOzAoH6DWMPQ/uMZyb46pVzMdy6KSe689EZWxy2kKJxc6TZ373MwpEWiCQtghElzTTeM8miyUji5qY9npRGwICEAWX0PFSiEhb18+7Yykr2RaYfw3ZBnqMJgzGZvrOGYflIrYYQ8gaVTqSH6sS3lC8zz+wSSJPn2kB7mEU= Message-ID: <8bd0f97a0703292053l2391d6eeh7440d7633301fdae@mail.gmail.com> Date: Thu, 29 Mar 2007 23:53:59 -0400 From: "Mike Frysinger" To: bryan.wu@analog.com Subject: Re: [PATCH] nommu arch dont zero the anonymous mapping by adding UNINITIALIZE flag Cc: "Andrew Morton" , "David Howells" , linux-kernel@vger.kernel.org In-Reply-To: <1175226172.15391.66.camel@roc-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1175226172.15391.66.camel@roc-desktop> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 3/29/07, Wu, Bryan wrote: > On architectures with MMU, malloc takes about the same speed, > indepentant of malloc size, while on the Blackfin (NOMMU), as the malloc > size increases, the time that malloc consumes grows.... err, this is not the direction we wanted to go ... this requires changes to the user<->kernel boundary which certainly will be rejected by the glibc maintainers since it implies breakage in POSIX behavior and is specific to no-mmu only ... the plan is to hold onto this cruft in Blackfin until we get this bug sorted out: http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3027 as the thing we'll send to mainline will be sane (a no-mmu specific kconfig option to control the memset in the kernel malloc) the memset in the kernel right now for no-mmu is by design, not defect ... we can chat about this more via Blackfin channels if you like, or just wait till we meet up in Shanghai -mike