From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f48.google.com (mail-ee0-f48.google.com [74.125.83.48]) by kanga.kvack.org (Postfix) with ESMTP id 128F76B0035 for ; Fri, 28 Mar 2014 10:32:59 -0400 (EDT) Received: by mail-ee0-f48.google.com with SMTP id b57so4124364eek.35 for ; Fri, 28 Mar 2014 07:32:59 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTP id ma4si2253031wic.20.2014.03.28.07.32.57 for ; Fri, 28 Mar 2014 07:32:58 -0700 (PDT) Message-ID: <533587FD.7000006@redhat.com> Date: Fri, 28 Mar 2014 10:32:29 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: Adding compression before/above swapcache References: <20140327222605.GB16495@medulla.variantweb.net> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dan Streetman , Seth Jennings Cc: Hugh Dickins , Mel Gorman , Michal Hocko , Bob Liu , Minchan Kim , Johannes Weiner , Weijie Yang , Andrew Morton , Linux-MM , linux-kernel On 03/28/2014 08:36 AM, Dan Streetman wrote: > Well my general idea was to modify shrink_page_list() so that instead > of calling add_to_swap() and then pageout(), anonymous pages would be > added to a compressed cache. I haven't worked out all the specific > details, but I am initially thinking that the compressed cache could > simply repurpose incoming pages to use as the compressed cache storage > (using its own page mapping, similar to swap page mapping), and then > add_to_swap() the storage pages when the compressed cache gets to a > certain size. Pages that don't compress well could just bypass the > compressed cache, and get sent the current route directly to > add_to_swap(). That sounds a lot like what zswap does. How is your proposal different? And, is there an easier way to implement that difference? :) -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751722AbaC1OdH (ORCPT ); Fri, 28 Mar 2014 10:33:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:63142 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751305AbaC1OdE (ORCPT ); Fri, 28 Mar 2014 10:33:04 -0400 Message-ID: <533587FD.7000006@redhat.com> Date: Fri, 28 Mar 2014 10:32:29 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Dan Streetman , Seth Jennings CC: Hugh Dickins , Mel Gorman , Michal Hocko , Bob Liu , Minchan Kim , Johannes Weiner , Weijie Yang , Andrew Morton , Linux-MM , linux-kernel Subject: Re: Adding compression before/above swapcache References: <20140327222605.GB16495@medulla.variantweb.net> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/28/2014 08:36 AM, Dan Streetman wrote: > Well my general idea was to modify shrink_page_list() so that instead > of calling add_to_swap() and then pageout(), anonymous pages would be > added to a compressed cache. I haven't worked out all the specific > details, but I am initially thinking that the compressed cache could > simply repurpose incoming pages to use as the compressed cache storage > (using its own page mapping, similar to swap page mapping), and then > add_to_swap() the storage pages when the compressed cache gets to a > certain size. Pages that don't compress well could just bypass the > compressed cache, and get sent the current route directly to > add_to_swap(). That sounds a lot like what zswap does. How is your proposal different? And, is there an easier way to implement that difference? :)