From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx149.postini.com [74.125.245.149]) by kanga.kvack.org (Postfix) with SMTP id B57056B0092 for ; Tue, 7 May 2013 20:41:59 -0400 (EDT) Subject: Re: [RFC][PATCH 7/7] drain batch list during long operations From: Tim Chen In-Reply-To: <20130507212003.7990B2F5@viggo.jf.intel.com> References: <20130507211954.9815F9D1@viggo.jf.intel.com> <20130507212003.7990B2F5@viggo.jf.intel.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 07 May 2013 17:42:02 -0700 Message-ID: <1367973722.27102.267.camel@schen9-DESK> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, mgorman@suse.de On Tue, 2013-05-07 at 14:20 -0700, Dave Hansen wrote: > From: Dave Hansen > > This was a suggestion from Mel: > > http://lkml.kernel.org/r/20120914085634.GM11157@csn.ul.ie > > Any pages we collect on 'batch_for_mapping_removal' will have > their lock_page() held during the duration of their stay on the > list. If some other user is trying to get at them during this > time, they might end up having to wait for a while, especially if > we go off and do pageout() on some other page. > > This ensures that we drain the batch if we are about to perform a > writeout. > > I added some statistics to the __remove_mapping_batch() code to > track how large the lists are that we pass in to it. With this > patch, the average list length drops about 10% (from about 4.1 to > 3.8). The workload here was a make -j4 kernel compile on a VM > with 200MB of RAM. > > I've still got the statistics patch around if anyone is > interested. > > Signed-off-by: Dave Hansen I like this new patch series. Logic is cleaner than my previous attempt. Acked. Tim -- 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