Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752319AbbHSDXr (ORCPT ); Tue, 18 Aug 2015 23:23:47 -0400 Received: from mail-wi0-f180.google.com ([209.85.212.180]:37864 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751571AbbHSDXn (ORCPT ); Tue, 18 Aug 2015 23:23:43 -0400 Message-ID: <1439954620.3479.30.camel@gmail.com> Subject: Re: [PATCH 3/3] sched: Implement interface for cgroup unified hierarchy From: Mike Galbraith To: Tejun Heo Cc: Paul Turner , Peter Zijlstra , Ingo Molnar , Johannes Weiner , lizefan@huawei.com, cgroups , LKML , kernel-team , Linus Torvalds , Andrew Morton Date: Wed, 19 Aug 2015 05:23:40 +0200 In-Reply-To: <20150818203117.GC15739@mtj.duckdns.org> References: <1438641689-14655-1-git-send-email-tj@kernel.org> <1438641689-14655-4-git-send-email-tj@kernel.org> <20150804090711.GL25159@twins.programming.kicks-ass.net> <20150804151017.GD17598@mtj.duckdns.org> <20150805091036.GT25159@twins.programming.kicks-ass.net> <20150805143132.GK17598@mtj.duckdns.org> <20150818203117.GC15739@mtj.duckdns.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.11 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 851 Lines: 19 On Tue, 2015-08-18 at 13:31 -0700, Tejun Heo wrote: > So, this is a trade-off we're consciously making. If there are > common-enough use cases which require jumping across different cgroup > domains, we'll try to figure out a way to accomodate those but by > default migration is a very cold and expensive path. Hm. I know of a big data outfit to which attach/detach performance was important enough for them to have plucked an old experimental overhead reduction hack (mine) off lkml, and shipped it. It must have mattered a LOT for them (not suicidal crash test dummies) to have done that. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/