From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx155.postini.com [74.125.245.155]) by kanga.kvack.org (Postfix) with SMTP id 89BEE6B0005 for ; Thu, 7 Feb 2013 11:15:38 -0500 (EST) Received: from /spool/local by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 7 Feb 2013 09:14:47 -0700 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id D42C619D8042 for ; Thu, 7 Feb 2013 09:14:37 -0700 (MST) Received: from d03av06.boulder.ibm.com (d03av06.boulder.ibm.com [9.17.195.245]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r17GEZuJ145094 for ; Thu, 7 Feb 2013 09:14:36 -0700 Received: from d03av06.boulder.ibm.com (loopback [127.0.0.1]) by d03av06.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r17GGaM5022100 for ; Thu, 7 Feb 2013 09:16:37 -0700 Message-ID: <5113D291.2020903@linux.vnet.ibm.com> Date: Thu, 07 Feb 2013 10:13:05 -0600 From: Seth Jennings MIME-Version: 1.0 Subject: Re: [PATCHv2 8/9] zswap: add to mm/ References: <1357590280-31535-1-git-send-email-sjenning@linux.vnet.ibm.com> <1357590280-31535-9-git-send-email-sjenning@linux.vnet.ibm.com> <51030ADA.8030403@redhat.com> <510698F5.5060205@linux.vnet.ibm.com> <5107A2B8.4070505@parallels.com> In-Reply-To: <5107A2B8.4070505@parallels.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Lord Glauber Costa of Sealand Cc: Rik van Riel , Greg Kroah-Hartman , Andrew Morton , Nitin Gupta , Minchan Kim , Konrad Rzeszutek Wilk , Dan Magenheimer , Robert Jennings , Jenifer Hopper , Mel Gorman , Johannes Weiner , Larry Woodman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org On 01/29/2013 04:21 AM, Lord Glauber Costa of Sealand wrote: > On 01/28/2013 07:27 PM, Seth Jennings wrote: >> Yes, I prototyped a shrinker interface for zswap, but, as we both >> figured, it shrinks the zswap compressed pool too aggressively to the >> point of being useless. > Can't you advertise a smaller number of objects that you actively have? Thanks for looking at the code! An interesting idea. I'm just not sure how you would manage the underlying policy of how aggressively does zswap allow itself to be shrunk? The fact that zswap _only_ operates under memory pressure makes that policy difficult, because it is under continuous shrinking pressure, unlike other shrinkable caches in the kernel that spend most of their time operating in unconstrained or lightly/intermittently strained conditions. Thanks, Seth -- 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 S1758793Ab3BGQPf (ORCPT ); Thu, 7 Feb 2013 11:15:35 -0500 Received: from e38.co.us.ibm.com ([32.97.110.159]:60692 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757809Ab3BGQPe (ORCPT ); Thu, 7 Feb 2013 11:15:34 -0500 Message-ID: <5113D291.2020903@linux.vnet.ibm.com> Date: Thu, 07 Feb 2013 10:13:05 -0600 From: Seth Jennings User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Lord Glauber Costa of Sealand CC: Rik van Riel , Greg Kroah-Hartman , Andrew Morton , Nitin Gupta , Minchan Kim , Konrad Rzeszutek Wilk , Dan Magenheimer , Robert Jennings , Jenifer Hopper , Mel Gorman , Johannes Weiner , Larry Woodman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org Subject: Re: [PATCHv2 8/9] zswap: add to mm/ References: <1357590280-31535-1-git-send-email-sjenning@linux.vnet.ibm.com> <1357590280-31535-9-git-send-email-sjenning@linux.vnet.ibm.com> <51030ADA.8030403@redhat.com> <510698F5.5060205@linux.vnet.ibm.com> <5107A2B8.4070505@parallels.com> In-Reply-To: <5107A2B8.4070505@parallels.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13020716-5518-0000-0000-00000B5FB5EC Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/29/2013 04:21 AM, Lord Glauber Costa of Sealand wrote: > On 01/28/2013 07:27 PM, Seth Jennings wrote: >> Yes, I prototyped a shrinker interface for zswap, but, as we both >> figured, it shrinks the zswap compressed pool too aggressively to the >> point of being useless. > Can't you advertise a smaller number of objects that you actively have? Thanks for looking at the code! An interesting idea. I'm just not sure how you would manage the underlying policy of how aggressively does zswap allow itself to be shrunk? The fact that zswap _only_ operates under memory pressure makes that policy difficult, because it is under continuous shrinking pressure, unlike other shrinkable caches in the kernel that spend most of their time operating in unconstrained or lightly/intermittently strained conditions. Thanks, Seth