From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933129AbbFJAEx (ORCPT ); Tue, 9 Jun 2015 20:04:53 -0400 Received: from mail-pd0-f177.google.com ([209.85.192.177]:34779 "EHLO mail-pd0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933009AbbFJAEq (ORCPT ); Tue, 9 Jun 2015 20:04:46 -0400 Date: Wed, 10 Jun 2015 09:04:53 +0900 From: Minchan Kim To: Sergey Senozhatsky Cc: 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: <20150610000453.GB13376@bgram> References: <1433505838-23058-1-git-send-email-sergey.senozhatsky@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1433505838-23058-1-git-send-email-sergey.senozhatsky@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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-f49.google.com (mail-pa0-f49.google.com [209.85.220.49]) by kanga.kvack.org (Postfix) with ESMTP id AD8896B006E for ; Tue, 9 Jun 2015 20:04:46 -0400 (EDT) Received: by pabqy3 with SMTP id qy3so22615460pab.3 for ; Tue, 09 Jun 2015 17:04:46 -0700 (PDT) Received: from mail-pd0-x236.google.com (mail-pd0-x236.google.com. [2607:f8b0:400e:c02::236]) by mx.google.com with ESMTPS id da5si10935997pbc.20.2015.06.09.17.04.45 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Jun 2015 17:04:45 -0700 (PDT) Received: by pdjm12 with SMTP id m12so24629771pdj.3 for ; Tue, 09 Jun 2015 17:04:45 -0700 (PDT) Date: Wed, 10 Jun 2015 09:04:53 +0900 From: Minchan Kim Subject: Re: [RFC][PATCHv2 0/8] introduce automatic pool compaction Message-ID: <20150610000453.GB13376@bgram> References: <1433505838-23058-1-git-send-email-sergey.senozhatsky@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1433505838-23058-1-git-send-email-sergey.senozhatsky@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Sergey Senozhatsky Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky 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. 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. 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