From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751345AbdJ1Qto (ORCPT ); Sat, 28 Oct 2017 12:49:44 -0400 Received: from mail-qk0-f195.google.com ([209.85.220.195]:46112 "EHLO mail-qk0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751230AbdJ1Qtm (ORCPT ); Sat, 28 Oct 2017 12:49:42 -0400 X-Google-Smtp-Source: ABhQp+SLsnAUEV4euEGmbSeIvmCe5QWeF+9/tXjzHl8DbZMM4RsTki8g0UZUbE81UPUKXlZ3xrzCdQ== Date: Sat, 28 Oct 2017 09:49:37 -0700 From: Tejun Heo To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo Cc: linux-kernel@vger.kernel.org, David Carrillo-Cisneros , kernel-team@fb.com Subject: [PATCH] cgroup, perf_event: Fix perf cgroup hierarchy support Message-ID: <20171028164237.GA972780@devbig577.frc2.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 864c2357ca89 ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups") made list_update_cgroup_event() skip setting cpuctx->cgrp if no cgroup event targets %current's cgroup. This breaks perf_event's hierarchical support because events which target one of the ancestors get ignored. Fix it by using cgroup_is_descendant() test instead of equality. Signed-off-by: Tejun Heo Fixes: 864c2357ca89 ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups") Cc: stable@vger.kernel.org # v4.9+ Cc: David Carrillo-Cisneros --- kernel/events/core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 9d93db8..db2e630 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -901,9 +901,12 @@ list_update_cgroup_event(struct perf_event *event, cpuctx_entry = &cpuctx->cgrp_cpuctx_entry; /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/ if (add) { + struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx); + list_add(cpuctx_entry, this_cpu_ptr(&cgrp_cpuctx_list)); - if (perf_cgroup_from_task(current, ctx) == event->cgrp) - cpuctx->cgrp = event->cgrp; + if (cgroup_is_descendant(cgrp->css.cgroup, + event->cgrp->css.cgroup)) + cpuctx->cgrp = cgrp; } else { list_del(cpuctx_entry); cpuctx->cgrp = NULL;