From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f173.google.com (mail-pd0-f173.google.com [209.85.192.173]) by kanga.kvack.org (Postfix) with ESMTP id E58806B0038 for ; Tue, 7 Jul 2015 07:57:55 -0400 (EDT) Received: by pddu5 with SMTP id u5so37296950pdd.3 for ; Tue, 07 Jul 2015 04:57:55 -0700 (PDT) Received: from mail-pd0-x231.google.com (mail-pd0-x231.google.com. [2607:f8b0:400e:c02::231]) by mx.google.com with ESMTPS id le1si34369574pab.92.2015.07.07.04.57.54 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 07 Jul 2015 04:57:55 -0700 (PDT) Received: by pdbdz6 with SMTP id dz6so29982362pdb.0 for ; Tue, 07 Jul 2015 04:57:54 -0700 (PDT) From: Sergey Senozhatsky Subject: [PATCH v6 0/7] mm/zsmalloc: introduce automatic pool compaction Date: Tue, 7 Jul 2015 20:56:54 +0900 Message-Id: <1436270221-17844-1-git-send-email-sergey.senozhatsky@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky , Sergey Senozhatsky 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. v6: -- use new zs_pool stats API (Minchan) v5: -- account freed pages correctly v4: address review notes (Minchan) -- do not abort __zs_compact() quickly (Minchan) -- switch zsmalloc compaction to operate in terms of freed pages -- micro-optimize zs_can_compact() (Minchan) v3: -- drop almost_empty waterline adjustment patch (Minchan) -- do not hold class->lock for the entire compaction period (Minchan) v2: -- use a slab shrinker instead of triggering compaction from zs_free (Minchan) Sergey Senozhatsky (7): zsmalloc: drop unused variable `nr_to_migrate' zsmalloc: always keep per-class stats zsmalloc: introduce zs_can_compact() function zsmalloc: cosmetic compaction code adjustments zsmalloc/zram: introduce zs_pool_stats api zsmalloc: account the number of compacted pages zsmalloc: use shrinker to trigger auto-compaction Documentation/blockdev/zram.txt | 3 +- drivers/block/zram/zram_drv.c | 11 +- drivers/block/zram/zram_drv.h | 1 - include/linux/zsmalloc.h | 6 ++ mm/zsmalloc.c | 220 +++++++++++++++++++++++++++------------- 5 files changed, 164 insertions(+), 77 deletions(-) -- 2.4.5 -- 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