From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:56530 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752651AbdKFJO7 (ORCPT ); Mon, 6 Nov 2017 04:14:59 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tejun Heo , Thomas Gleixner , Arnaldo Carvalho de Melo , David Carrillo-Cisneros , Linus Torvalds , Peter Zijlstra , kernel-team@fb.com, Ingo Molnar Subject: [PATCH 4.13 34/36] perf/cgroup: Fix perf cgroup hierarchy support Date: Mon, 6 Nov 2017 10:12:47 +0100 Message-Id: <20171106085048.562370214@linuxfoundation.org> In-Reply-To: <20171106085047.005824077@linuxfoundation.org> References: <20171106085047.005824077@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tejun Heo commit be96b316deff35e119760982c43af74e606fa143 upstream. The following commit: 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 Acked-by: Thomas Gleixner Cc: Arnaldo Carvalho de Melo Cc: David Carrillo-Cisneros Cc: Linus Torvalds Cc: Peter Zijlstra Cc: kernel-team@fb.com Fixes: 864c2357ca89 ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups") Link: http://lkml.kernel.org/r/20171028164237.GA972780@devbig577.frc2.facebook.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/events/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -901,9 +901,11 @@ list_update_cgroup_event(struct perf_eve 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;