From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756268AbcFHOLJ (ORCPT ); Wed, 8 Jun 2016 10:11:09 -0400 Received: from mail-pf0-f172.google.com ([209.85.192.172]:33119 "EHLO mail-pf0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752362AbcFHOLH (ORCPT ); Wed, 8 Jun 2016 10:11:07 -0400 Date: Wed, 8 Jun 2016 23:10:58 +0900 From: Sergey Senozhatsky To: Ganesh Mahendran Cc: Minchan Kim , Linux-MM , linux-kernel , Andrew Morton , Nitin Gupta , Sergey Senozhatsky , rostedt@goodmis.org, mingo@redhat.com Subject: Re: [PATCH] mm/zsmalloc: add trace events for zs_compact Message-ID: <20160608141058.GB498@swordfish> References: <1465289804-4913-1-git-send-email-opensource.ganesh@gmail.com> <20160608001625.GB27258@bbox> <20160608051352.GA28155@bbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On (06/08/16 14:39), Ganesh Mahendran wrote: > >> > On Tue, Jun 07, 2016 at 04:56:44PM +0800, Ganesh Mahendran wrote: > >> >> Currently zsmalloc is widely used in android device. > >> >> Sometimes, we want to see how frequently zs_compact is > >> >> triggered or how may pages freed by zs_compact(), or which > >> >> zsmalloc pool is compacted. > >> >> > >> >> Most of the time, user can get the brief information from > >> >> trace_mm_shrink_slab_[start | end], but in some senario, > >> >> they do not use zsmalloc shrinker, but trigger compaction manually. > >> >> So add some trace events in zs_compact is convenient. Also we > >> >> can add some zsmalloc specific information(pool name, total compact > >> >> pages, etc) in zsmalloc trace. > >> > > >> > Sorry, I cannot understand what's the problem now and what you want to > >> > solve. Could you elaborate it a bit? > >> > > >> > Thanks. > >> > >> We have backported the zs_compact() to our product(kernel 3.18). > >> It is usefull for a longtime running device. > >> But there is not a convenient way to get the detailed information > >> of zs_comapct() which is usefull for performance optimization. > >> Information about how much time zs_compact used, which pool is > >> compacted, how many page freed, etc. sorry, couldn't check my email earlier. zs_compact() is just one of the N sites that are getting called by the shrinker; optimization here will "solve" only 1/N of the problems. are there any trace events in any other shrinker callbacks? why trace_mm_shrink_slab_start()/trace_mm_shrink_slab_end()/etc. don't work you? -ss