Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759796AbZJMNFR (ORCPT ); Tue, 13 Oct 2009 09:05:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759762AbZJMNFQ (ORCPT ); Tue, 13 Oct 2009 09:05:16 -0400 Received: from 124x34x33x190.ap124.ftth.ucom.ne.jp ([124.34.33.190]:56553 "EHLO master.linux-sh.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759750AbZJMNFP (ORCPT ); Tue, 13 Oct 2009 09:05:15 -0400 Date: Tue, 13 Oct 2009 22:03:36 +0900 From: Paul Mundt To: Mike Frysinger Cc: uclinux-dev@uclinux.org, David Howells , David McCullough , Greg Ungerer , linux-kernel@vger.kernel.org, uclinux-dist-devel@blackfin.uclinux.org, Jie Zhang , Robin Getz Subject: Re: [PATCH v2] NOMMU: fix malloc performance by adding uninitialized flag Message-ID: <20091013130336.GA1245@linux-sh.org> References: <32310.1255428618@redhat.com> <1255432821-1104-1-git-send-email-vapier@gentoo.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1255432821-1104-1-git-send-email-vapier@gentoo.org> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1167 Lines: 24 On Tue, Oct 13, 2009 at 07:20:21AM -0400, Mike Frysinger wrote: > From: Jie Zhang > > The NOMMU code currently clears all anonymous mmapped memory. While this > is what we want in the default case, all memory allocation from userspace > under NOMMU has to go through this interface, including malloc() which is > allowed to return uninitialized memory. This can easily be a significant > performance penalty. So for constrained embedded systems were security is > irrelevant, allow people to avoid clearing memory unnecessarily. > > This also alters the ELF-FDPIC binfmt such that it obtains uninitialised > memory for the brk and stack region. > > Signed-off-by: Jie Zhang > Signed-off-by: Robin Getz > Signed-off-by: Mike Frysinger > Signed-off-by: David Howells Acked-by: Paul Mundt -- 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/