From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f197.google.com (mail-io0-f197.google.com [209.85.223.197]) by kanga.kvack.org (Postfix) with ESMTP id C2CFB6B0005 for ; Fri, 17 Jun 2016 02:43:33 -0400 (EDT) Received: by mail-io0-f197.google.com with SMTP id g13so135901363ioj.3 for ; Thu, 16 Jun 2016 23:43:33 -0700 (PDT) Received: from lgeamrelo11.lge.com (LGEAMRELO11.lge.com. [156.147.23.51]) by mx.google.com with ESMTP id y66si3273780ita.42.2016.06.16.23.43.32 for ; Thu, 16 Jun 2016 23:43:32 -0700 (PDT) Date: Fri, 17 Jun 2016 15:43:30 +0900 From: Minchan Kim Subject: Re: [PATCH v1 3/3] mm: per-process reclaim Message-ID: <20160617064330.GD2374@bbox> References: <1465804259-29345-1-git-send-email-minchan@kernel.org> <1465804259-29345-4-git-send-email-minchan@kernel.org> <20160613150653.GA30642@cmpxchg.org> <20160615004027.GA17127@bbox> <20160616144102.GA17692@cmpxchg.org> MIME-Version: 1.0 In-Reply-To: <20160616144102.GA17692@cmpxchg.org> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Rik van Riel , Sangwoo Park Hi Hannes, On Thu, Jun 16, 2016 at 10:41:02AM -0400, Johannes Weiner wrote: > On Wed, Jun 15, 2016 at 09:40:27AM +0900, Minchan Kim wrote: > > A question is it seems cgroup2 doesn't have per-cgroup swappiness. > > Why? > > > > I think we need it in one-cgroup-per-app model. > > Can you explain why you think that? > > As we have talked about this recently in the LRU balancing thread, > swappiness is the cost factor between file IO and swapping, so the > only situation I can imagine you'd need a memcg swappiness setting is > when you have different cgroups use different storage devices that do > not have comparable speeds. > > So I'm not sure I understand the relationship to an app-group model. Sorry for lacking the inforamtion. I should have written more clear. In fact, what we need is *per-memcg-swap-device*. What I want is to avoid kill background application although memory is overflow because cold launcing of app takes a very long time compared to resume(ie, just switching). I also want to keep a mount of free pages in the memory so that new application startup cannot be stuck by reclaim activities. To get free memory, I want to reclaim less important app rather than killing. In this time, we can support two swap devices. A one is zram, other is slow storage but much bigger than zram size. Then, we can use storage swap to reclaim pages for not-important app while we can use zram swap for for important app(e.g., forground app, system services, daemon and so on). IOW, we want to support mutiple swap device with one-cgroup-per-app and the storage speed is totally different. -- 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