From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f178.google.com (mail-pd0-f178.google.com [209.85.192.178]) by kanga.kvack.org (Postfix) with ESMTP id C592A6B006C for ; Thu, 4 Dec 2014 02:21:03 -0500 (EST) Received: by mail-pd0-f178.google.com with SMTP id g10so17057275pdj.23 for ; Wed, 03 Dec 2014 23:21:03 -0800 (PST) Received: from lgemrelse7q.lge.com (LGEMRELSE7Q.lge.com. [156.147.1.151]) by mx.google.com with ESMTP id jd6si16036007pbd.84.2014.12.03.23.21.01 for ; Wed, 03 Dec 2014 23:21:02 -0800 (PST) Message-ID: <54800B73.8090503@lge.com> Date: Thu, 04 Dec 2014 16:21:23 +0900 From: =?UTF-8?B?IuuwleyKue2YuC/ssYXsnoTsl7Dqtazsm5AvU1cgUGxhdGZvcm0o7JewKQ==?= =?UTF-8?B?QU9U7YyAKHNldW5naG8xLnBhcmtAbGdlLmNvbSki?= MIME-Version: 1.0 Subject: Re: [RFC 0/6] zsmalloc support compaction References: <1417488587-28609-1-git-send-email-minchan@kernel.org> <548003F1.2080004@lge.com> In-Reply-To: <548003F1.2080004@lge.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Nitin Gupta , Dan Streetman , Seth Jennings , Sergey Senozhatsky , Luigi Semenzato , Jerome Marchand , juno.choi@lge.com Hi, Minchan. Sorry, I got it. You made zsmalloc pages movable. forget it. Seungho. 2014-12-04 i??i?? 3:49i?? "e??i?1i?,/i+-?i??i??eu!i??/SW Platform(i??)AOTi?? (seungho1.park@lge.com)" i?'(e??) i?' e,?: > Hi, Minchan. > > I have a question. > The problem mentioned can't be resolved with compaction? > Is there any reason that zsmalloc pages can't be moved by compaction > operation in direct reclaim? > > 2014-12-02 i??i ? 11:49i?? Minchan Kim i?'(e??) i?' e,?: >> Recently, there was issue about zsmalloc fragmentation and >> I got a report from Juno that new fork failed although there >> are plenty of free pages in the system. >> His investigation revealed zram is one of the culprit to make >> heavy fragmentation so there was no more contiguous 16K page >> for pgd to fork in the ARM. >> >> This patchset implement *basic* zsmalloc compaction support >> and zram utilizes it so admin can do >> "echo 1 > /sys/block/zram0/compact" >> >> Actually, ideal is that mm migrate code is aware of zram pages and >> migrate them out automatically without admin's manual opeartion >> when system is out of contiguous page. Howver, we need more thinking >> before adding more hooks to migrate.c. Even though we implement it, >> we need manual trigger mode, too so I hope we could enhance >> zram migration stuff based on this primitive functions in future. >> >> I just tested it on only x86 so need more testing on other arches. >> Additionally, I should have a number for zsmalloc regression >> caused by indirect layering. Unfortunately, I don't have any >> ARM test machine on my desk. I will get it soon and test it. >> Anyway, before further work, I'd like to hear opinion. >> >> Pathset is based on v3.18-rc6-mmotm-2014-11-26-15-45. >> >> Thanks. >> >> Minchan Kim (6): >> zsmalloc: expand size class to support sizeof(unsigned long) >> zsmalloc: add indrection layer to decouple handle from object >> zsmalloc: implement reverse mapping >> zsmalloc: encode alloced mark in handle object >> zsmalloc: support compaction >> zram: support compaction >> >> drivers/block/zram/zram_drv.c | 24 ++ >> drivers/block/zram/zram_drv.h | 1 + >> include/linux/zsmalloc.h | 1 + >> mm/zsmalloc.c | 596 >> +++++++++++++++++++++++++++++++++++++----- >> 4 files changed, 552 insertions(+), 70 deletions(-) >> > -- 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