From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754099AbbFJAHi (ORCPT ); Tue, 9 Jun 2015 20:07:38 -0400 Received: from mail-pa0-f42.google.com ([209.85.220.42]:33337 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752671AbbFJAHa (ORCPT ); Tue, 9 Jun 2015 20:07:30 -0400 Date: Wed, 10 Jun 2015 09:07:55 +0900 From: Sergey Senozhatsky To: Minchan Kim Cc: Sergey Senozhatsky , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky Subject: Re: [RFC][PATCHv2 0/8] introduce automatic pool compaction Message-ID: <20150610000755.GB596@swordfish> References: <1433505838-23058-1-git-send-email-sergey.senozhatsky@gmail.com> <20150610000453.GB13376@bgram> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150610000453.GB13376@bgram> User-Agent: Mutt/1.5.23+89 (0255b37be491) (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On (06/10/15 09:04), Minchan Kim wrote: > Hello Sergey, > > Thanks for looking this and sorry for the delay for review. > I don't have a time to hold a review yet. > Please wait and I try to get a time within this week. > > Thanks for your patience. sure, no problem at all. -ss > On Fri, Jun 05, 2015 at 09:03:50PM +0900, Sergey Senozhatsky wrote: > > Hello, > > > > This patch set tweaks compaction and makes it possible to trigger > > pool compaction automatically when system is getting low on memory. > > > > zsmalloc in some cases can suffer from a notable fragmentation and > > compaction can release some considerable amount of memory. The problem > > here is that currently we fully rely on user space to perform compaction > > when needed. However, performing zsmalloc compaction is not always an > > obvious thing to do. For example, suppose we have a `idle' fragmented > > (compaction was never performed) zram device and system is getting low > > on memory due to some 3rd party user processes (gcc LTO, or firefox, etc.). > > It's quite unlikely that user space will issue zpool compaction in this > > case. Besides, user space cannot tell for sure how badly pool is > > fragmented; however, this info is known to zsmalloc and, hence, to a > > shrinker. > > > > v2: > > -- use a slab shrinker instead of triggering compaction from zs_free (Minchan) > > > > Sergey Senozhatsky (8): > > zsmalloc: drop unused variable `nr_to_migrate' > > zsmalloc: partial page ordering within a fullness_list > > zsmalloc: lower ZS_ALMOST_FULL waterline > > zsmalloc: always keep per-class stats > > zsmalloc: introduce zs_can_compact() function > > zsmalloc: cosmetic compaction code adjustments > > zsmalloc/zram: move `num_migrated' to zs_pool > > zsmalloc: register a shrinker to trigger auto-compaction > > > > drivers/block/zram/zram_drv.c | 12 +-- > > drivers/block/zram/zram_drv.h | 1 - > > include/linux/zsmalloc.h | 1 + > > mm/zsmalloc.c | 228 +++++++++++++++++++++++++++--------------- > > 4 files changed, 152 insertions(+), 90 deletions(-) > > > > -- > > 2.4.2.387.gf86f31a > > > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f46.google.com (mail-pa0-f46.google.com [209.85.220.46]) by kanga.kvack.org (Postfix) with ESMTP id 59D846B0070 for ; Tue, 9 Jun 2015 20:07:31 -0400 (EDT) Received: by pabqy3 with SMTP id qy3so22653097pab.3 for ; Tue, 09 Jun 2015 17:07:31 -0700 (PDT) Received: from mail-pa0-x235.google.com (mail-pa0-x235.google.com. [2607:f8b0:400e:c03::235]) by mx.google.com with ESMTPS id il2si10914569pbc.120.2015.06.09.17.07.30 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Jun 2015 17:07:30 -0700 (PDT) Received: by pacyx8 with SMTP id yx8so22724496pac.2 for ; Tue, 09 Jun 2015 17:07:30 -0700 (PDT) Date: Wed, 10 Jun 2015 09:07:55 +0900 From: Sergey Senozhatsky Subject: Re: [RFC][PATCHv2 0/8] introduce automatic pool compaction Message-ID: <20150610000755.GB596@swordfish> References: <1433505838-23058-1-git-send-email-sergey.senozhatsky@gmail.com> <20150610000453.GB13376@bgram> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150610000453.GB13376@bgram> Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Sergey Senozhatsky , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky Hello, On (06/10/15 09:04), Minchan Kim wrote: > Hello Sergey, > > Thanks for looking this and sorry for the delay for review. > I don't have a time to hold a review yet. > Please wait and I try to get a time within this week. > > Thanks for your patience. sure, no problem at all. -ss > On Fri, Jun 05, 2015 at 09:03:50PM +0900, Sergey Senozhatsky wrote: > > Hello, > > > > This patch set tweaks compaction and makes it possible to trigger > > pool compaction automatically when system is getting low on memory. > > > > zsmalloc in some cases can suffer from a notable fragmentation and > > compaction can release some considerable amount of memory. The problem > > here is that currently we fully rely on user space to perform compaction > > when needed. However, performing zsmalloc compaction is not always an > > obvious thing to do. For example, suppose we have a `idle' fragmented > > (compaction was never performed) zram device and system is getting low > > on memory due to some 3rd party user processes (gcc LTO, or firefox, etc.). > > It's quite unlikely that user space will issue zpool compaction in this > > case. Besides, user space cannot tell for sure how badly pool is > > fragmented; however, this info is known to zsmalloc and, hence, to a > > shrinker. > > > > v2: > > -- use a slab shrinker instead of triggering compaction from zs_free (Minchan) > > > > Sergey Senozhatsky (8): > > zsmalloc: drop unused variable `nr_to_migrate' > > zsmalloc: partial page ordering within a fullness_list > > zsmalloc: lower ZS_ALMOST_FULL waterline > > zsmalloc: always keep per-class stats > > zsmalloc: introduce zs_can_compact() function > > zsmalloc: cosmetic compaction code adjustments > > zsmalloc/zram: move `num_migrated' to zs_pool > > zsmalloc: register a shrinker to trigger auto-compaction > > > > drivers/block/zram/zram_drv.c | 12 +-- > > drivers/block/zram/zram_drv.h | 1 - > > include/linux/zsmalloc.h | 1 + > > mm/zsmalloc.c | 228 +++++++++++++++++++++++++++--------------- > > 4 files changed, 152 insertions(+), 90 deletions(-) > > > > -- > > 2.4.2.387.gf86f31a > > > -- 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