Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753251Ab1EJW5h (ORCPT ); Tue, 10 May 2011 18:57:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44195 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753149Ab1EJW5g (ORCPT ); Tue, 10 May 2011 18:57:36 -0400 Date: Tue, 10 May 2011 23:57:00 +0100 From: Alasdair G Kergon To: Linus Torvalds , Matthew Wilcox , Zdenek Kabelac , Mikulas Patocka , linux-kernel@vger.kernel.org, linux-parisc@vger.kernel.org, Hugh Dickins , Oleg Nesterov , agk@redhat.com Subject: Re: [PATCH] Don't mlock guardpage if the stack is growing up Message-ID: <20110510225659.GE9253@agk-dp.fab.redhat.com> Mail-Followup-To: Alasdair G Kergon , Linus Torvalds , Matthew Wilcox , Zdenek Kabelac , Mikulas Patocka , linux-kernel@vger.kernel.org, linux-parisc@vger.kernel.org, Hugh Dickins , Oleg Nesterov References: <4DC7D37F.9040308@redhat.com> <20110509224511.GC15227@parisc-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Red Hat UK Ltd. Registered in England and Wales, number 03798903. Registered Office: Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 966 Lines: 22 On Mon, May 09, 2011 at 03:56:11PM -0700, Linus Torvalds wrote: > So there are sane semantics for the concept, and it would be easy to > do in the kernel. Whether it's worth doing, I dunno. At this point we have a workaround that seems to work for us. I find it ugly and it has needed some tweaking already but we can cope. If others find similar problems to ours and start replicating the logic we're using, then that would be the time to give serious thought to a clean 'sparse' extension. (Maybe marking individual mappings as MAP_SPARSE and adding a MCL_NO_SPARSE option to ignore them sounds most promising to me.) (What other software packages make use of mlockall() and under what circumstances?) Alasdair -- 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/