Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751312AbWAQAYQ (ORCPT ); Mon, 16 Jan 2006 19:24:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751313AbWAQAYQ (ORCPT ); Mon, 16 Jan 2006 19:24:16 -0500 Received: from elvis.mu.org ([192.203.228.196]:32967 "EHLO elvis.mu.org") by vger.kernel.org with ESMTP id S1751312AbWAQAYP (ORCPT ); Mon, 16 Jan 2006 19:24:15 -0500 Message-ID: <43CC3922.2070205@FreeBSD.org> Date: Mon, 16 Jan 2006 16:24:02 -0800 From: Suleiman Souhlal User-Agent: Mozilla Thunderbird 1.0.7 (X11/20051204) X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Eric W. Biederman" CC: Andrea Arcangeli , Badari Pulavarty , Andrew Morton , linux-kernel@vger.kernel.org, hugh@veritas.com, dvhltc@us.ibm.com, linux-mm@kvack.org, blaisorblade@yahoo.it, jdike@addtoit.com Subject: Re: differences between MADV_FREE and MADV_DONTNEED References: <20051102014321.GG24051@opteron.random> <1130947957.24503.70.camel@localhost.localdomain> <20051111162511.57ee1af3.akpm@osdl.org> <1131755660.25354.81.camel@localhost.localdomain> <20051111174309.5d544de4.akpm@osdl.org> <43757263.2030401@us.ibm.com> <20060116130649.GE15897@opteron.random> <43CBC37F.60002@FreeBSD.org> <20060116162808.GG15897@opteron.random> <43CBD1C4.5020002@FreeBSD.org> <20060116172449.GL15897@opteron.random> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 750 Lines: 19 Eric W. Biederman wrote: > As I recall the logic with DONTNEED was to mark the mapping of > the page clean so the page didn't need to be swapped out, it could > just be dropped. > > That is why they anonymous and the file backed cases differ. > > Part of the point is to avoid the case of swapping the pages out if > the application doesn't care what is on them anymore. Well, imho, MADV_DONTNEED should mean "I won't need this anytime soon", and MADV_FREE "I will never need this again". -- Suleiman - 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/