From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760428AbbLCPR2 (ORCPT ); Thu, 3 Dec 2015 10:17:28 -0500 Received: from mail-yk0-f169.google.com ([209.85.160.169]:34424 "EHLO mail-yk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756260AbbLCPR0 (ORCPT ); Thu, 3 Dec 2015 10:17:26 -0500 Date: Thu, 3 Dec 2015 10:17:24 -0500 From: Tejun Heo To: Li Zefan Cc: Johannes Weiner , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Aleksa Sarai Subject: Re: [PATCH for-4.4-fixes] cgroup_pids: don't account for the root cgroup Message-ID: <20151203151724.GF27463@mtj.duckdns.org> References: <20151130224543.GC9039@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151130224543.GC9039@mtj.duckdns.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 30, 2015 at 05:45:43PM -0500, Tejun Heo wrote: > From 7bbb8d4e913853a1346d95745ca8092f0cc8ce00 Mon Sep 17 00:00:00 2001 > From: Tejun Heo > Date: Mon, 30 Nov 2015 17:24:34 -0500 > > Because accounting resources for the root cgroup sometimes incurs > measureable overhead for workloads which don't care about cgroup and > often ends up calculating a number which is available elsewhere in a > slightly different form, cgroup is not in the business of providing > system-wide statistics. The pids controller which was introduced > recently was exposing "pids.current" at the root. This patch disable > accounting for root cgroup and removes the file from the root > directory. > > While this is a userland visible behavior change, pids has been > available only in one version and was badly broken there, so I don't > think this will be noticeable. If it turns out to be a problem, we > can reinstate it for v1 hierarchies. > > Signed-off-by: Tejun Heo > Cc: Aleksa Sarai Applying to cgroup/for-4.4-fixes. Thanks. -- tejun