From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <461DCDDA.2030502@yahoo.com.au> Date: Thu, 12 Apr 2007 16:12:42 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [PATCH] make MADV_FREE lazily free memory References: <461C6452.1000706@redhat.com> <461D6413.6050605@cosmosbay.com> <461D67A9.5020509@redhat.com> <461DC75B.8040200@cosmosbay.com> <461DCCEB.70004@yahoo.com.au> In-Reply-To: <461DCCEB.70004@yahoo.com.au> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Eric Dumazet , Rik van Riel , linux-kernel , linux-mm , Ulrich Drepper List-ID: Nick Piggin wrote: > Eric Dumazet wrote: > >>> Two things can happen here. >>> >>> If this program used the pages before the kernel needed >>> them, the program will be reusing its old pages. >> >> >> >> ah ok, this is because accessed/dirty bits are set by hardware and not >> a page fault. > > > No it isn't. That is to say, it isn't required for correctness. But if the question was about avoiding a fault, then yes ;) But as Linus recently said, even hardware handled faults still take expensive microarchitectural traps. > >> Is it true for all architectures ? > > > No. > -- SUSE Labs, Novell Inc. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org