From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f178.google.com (mail-pf0-f178.google.com [209.85.192.178]) by kanga.kvack.org (Postfix) with ESMTP id 92C7E6B0005 for ; Mon, 14 Mar 2016 21:04:21 -0400 (EDT) Received: by mail-pf0-f178.google.com with SMTP id n5so3787452pfn.2 for ; Mon, 14 Mar 2016 18:04:21 -0700 (PDT) Received: from mail-pf0-x22e.google.com (mail-pf0-x22e.google.com. [2607:f8b0:400e:c00::22e]) by mx.google.com with ESMTPS id st10si6850167pab.60.2016.03.14.18.04.20 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 14 Mar 2016 18:04:20 -0700 (PDT) Received: by mail-pf0-x22e.google.com with SMTP id u190so3737358pfb.3 for ; Mon, 14 Mar 2016 18:04:20 -0700 (PDT) Date: Tue, 15 Mar 2016 10:05:42 +0900 From: Sergey Senozhatsky Subject: Re: [RFC][PATCH v3 2/5] mm/zsmalloc: remove shrinker compaction callbacks Message-ID: <20160315010542.GB2126@swordfish> References: <1457016363-11339-1-git-send-email-sergey.senozhatsky@gmail.com> <1457016363-11339-3-git-send-email-sergey.senozhatsky@gmail.com> <20160314063207.GD10675@bbox> <20160314074523.GB542@swordfish> <20160315005249.GB19514@bbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160315005249.GB19514@bbox> Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Sergey Senozhatsky , Sergey Senozhatsky , Andrew Morton , Joonsoo Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org On (03/15/16 09:52), Minchan Kim wrote: [..] > > > I suggested to remove shrinker compaction but while I review your > > > first patch in this thread, I thought we need upper-bound to > > > compact zspage so background work can bail out for latency easily. > > > IOW, the work could give up the job. In such case, we might need > > > fall-back scheme to continue the job. And I think that could be > > > a shrinker. > > > > > > What do you think? > > > > wouldn't this unnecessarily complicate the whole thing? we would > > have > > a) a compaction that can be triggered by used space > > Maybe, user space? :) haha, yes! sorry, I do quite a lot of typos. > > b) a compaction from zs_free() that can bail out > > c) a compaction triggered by the shrinker. > > > > all 3 three can run simultaneously. > > Yeb. > > > > > > > _if_ we can keep every class below its watermark, we can reduce the > > need of "c)". > > But the problem is timing. We cannot guarantee when background > compaction triggers while shrinker is interop with VM so we should > do the job instantly for the system. we can have pool's compaction-kthread that we will wake_up() every time we need a compaction, with no dependency on workqueue or shrinker. -ss -- 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