From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753143AbbCIAtP (ORCPT ); Sun, 8 Mar 2015 20:49:15 -0400 Received: from mail-pd0-f180.google.com ([209.85.192.180]:33067 "EHLO mail-pd0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751170AbbCIAtK (ORCPT ); Sun, 8 Mar 2015 20:49:10 -0400 Date: Mon, 9 Mar 2015 09:49:00 +0900 From: Minchan Kim To: Sergey Senozhatsky Cc: akpm@linux-foundation.org, ddstreet@ieee.org, gunho.lee@lge.com, iamjoonsoo.kim@lge.com, jmarchan@redhat.com, juno.choi@lge.com, mel@csn.ul.ie, ngupta@vflare.org, semenzato@google.com, sergey.senozhatsky@gmail.com, sjennings@variantweb.net, mm-commits@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: + zram-support-compaction.patch added to -mm tree Message-ID: <20150309004859.GB15184@blaptop> References: <54f780fc.3sOWZKr7rufmI85r%akpm@linux-foundation.org> <20150305052941.GK14927@swordfish> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150305052941.GK14927@swordfish> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Sergey, On Thu, Mar 05, 2015 at 02:29:42PM +0900, Sergey Senozhatsky wrote: > On (03/04/15 14:02), akpm@linux-foundation.org wrote: > > +What: /sys/block/zram/compact > > +Date: August 2015 > > +Contact: Minchan Kim > > +Description: > > + The compact file is write-only and trigger compaction for > > + allocator zrm uses. The allocator moves some objects so that > > + it could free fragment space. > > + > > +What: /sys/block/zram/num_migrated > > +Date: August 2015 > > +Contact: Minchan Kim > > +Description: > > + The compact file is read-only and shows how many object > > + migrated by compaction. > > diff -puN drivers/block/zram/zram_drv.c~zram-support-compaction drivers/block/zram/zram_drv.c > > --- a/drivers/block/zram/zram_drv.c~zram-support-compaction > > +++ a/drivers/block/zram/zram_drv.c > > @@ -70,6 +70,27 @@ static inline struct zram *dev_to_zram(s > > return (struct zram *)dev_to_disk(dev)->private_data; > > } > > First of all, my apologies to Andrew Morton. if I reply to this email, my mutt for > some reason replaces akpm at linux-foundation.org with linux-kernel at vger.kernel.org > (I can't see why this is happening, but this is somehow a `stable behaviour'). I didn't > spot this, so this is why Andrew was not Cc-d to my previous reply to this eamil. > > > > > rather a discussion question. > > Minchan, do you want to provide num_migrated as part of zsmalloc stats rather > than having yet another zram attr? we already provide zsmalloc stats and this > type of information seems to belong there. just idea. Hmm, CONFIG_ZSMALLOC_STAT is actually to show zsmalloc internals. That's why it is on debugfs. If we add the stat into zsmalloc, we should turn on debugfs and CONFIG_ZSMALLOC_STAT to see *a* stat. Even, CONFIG_ZSMALLOC_STAT will add unncessary overheads to account another stats fo zsmalloc internals. As well, if we add auto-compacion like stuff in zsmalloc(ie, it will trigger by itself if fragmention is over to predefined theshold), the stat will accumulate stat while someone want to see snapshot compaction effiecieny of the moment. So, I want to keep it in zram now. -- Kind regards, Minchan Kim