From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 31 Jan 2001 05:23:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 31 Jan 2001 05:23:25 -0500 Received: from zeus.kernel.org ([209.10.41.242]:59869 "EHLO zeus.kernel.org") by vger.kernel.org with ESMTP id ; Wed, 31 Jan 2001 05:23:16 -0500 Date: Wed, 31 Jan 2001 10:21:58 +0000 From: "Stephen C. Tweedie" To: Marcelo Tosatti Cc: lkml , linux-mm@kvack.org, Stephen Tweedie Subject: Re: [PATCH] vma limited swapin readahead Message-ID: <20010131102158.O11607@redhat.com> In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2i In-Reply-To: ; from marcelo@conectiva.com.br on Wed, Jan 31, 2001 at 01:05:02AM -0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Wed, Jan 31, 2001 at 01:05:02AM -0200, Marcelo Tosatti wrote: > > However, the pages which are contiguous on swap are not necessarily > contiguous in the virtual memory area where the fault happened. That means > the swapin readahead code may read pages which are not related to the > process which suffered a page fault. > Yes, but reading extra sectors is cheap, and throwing the pages out of memory again if they turn out not to be needed is also cheap. The on-disk swapped pages are likely to have been swapped out at roughly the same time, which is at least a modest indicator of being of the same age and likely to have been in use at the same time in the past. I'd like to see at lest some basic performance numbers on this, though. Cheers, Stephen - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/