Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030253AbWEKPPx (ORCPT ); Thu, 11 May 2006 11:15:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030257AbWEKPPx (ORCPT ); Thu, 11 May 2006 11:15:53 -0400 Received: from gold.veritas.com ([143.127.12.110]:14664 "EHLO gold.veritas.com") by vger.kernel.org with ESMTP id S1030253AbWEKPPw (ORCPT ); Thu, 11 May 2006 11:15:52 -0400 X-IronPort-AV: i="4.05,116,1146466800"; d="scan'208"; a="59423634:sNHT28593516" Date: Thu, 11 May 2006 16:15:43 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@blonde.wat.veritas.com To: Adam Litke cc: Christoph Hellwig , linux-mm@kvack.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] Hugetlb demotion for x86 In-Reply-To: <1147297535.24029.114.camel@localhost.localdomain> Message-ID: References: <1147287400.24029.81.camel@localhost.localdomain> <20060510200516.GA30346@infradead.org> <1147293156.24029.95.camel@localhost.localdomain> <20060510204928.GA31315@infradead.org> <1147297535.24029.114.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 11 May 2006 15:15:51.0860 (UTC) FILETIME=[CA792740:01C6750D] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1082 Lines: 26 On Wed, 10 May 2006, Adam Litke wrote: > > Strict overcommit is there for shared mappings. When private mapping I presume that by "strict overcommit" you mean "strict no overcommit". > support was added, people agreed that full overcommit should apply to > private mappings for the same reasons normal page overcommit is desired. I'm not sure how wide that agreement was. But what I wanted to say is... > For one: an application using lots of private huge pages should not be > prohibited from forking if it's likely to just exec a small helper > program. This is an excellent use for madvise(start, length, MADV_DONTFORK). Though it was added mainly for RDMA issues, it's a great way for a program with a huge commitment to exclude areas of its address space from the fork, so making that fork much more likely to succeed. Hugh - 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/