From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754842AbcFPOlQ (ORCPT ); Thu, 16 Jun 2016 10:41:16 -0400 Received: from gum.cmpxchg.org ([85.214.110.215]:59890 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754079AbcFPOlO (ORCPT ); Thu, 16 Jun 2016 10:41:14 -0400 Date: Thu, 16 Jun 2016 10:41:02 -0400 From: Johannes Weiner To: Minchan Kim Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Rik van Riel , Sangwoo Park Subject: Re: [PATCH v1 3/3] mm: per-process reclaim Message-ID: <20160616144102.GA17692@cmpxchg.org> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160615004027.GA17127@bbox> User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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.