* [PATCH] cgroup, perf_event: Fix perf cgroup hierarchy support
@ 2017-10-28 16:49 Tejun Heo
2017-10-30 10:20 ` Peter Zijlstra
2017-10-30 11:26 ` [tip:perf/urgent] perf/cgroup: " tip-bot for Tejun Heo
0 siblings, 2 replies; 3+ messages in thread
From: Tejun Heo @ 2017-10-28 16:49 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo
Cc: linux-kernel, David Carrillo-Cisneros, kernel-team
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 <tj@kernel.org>
Fixes: 864c2357ca89 ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups")
Cc: stable@vger.kernel.org # v4.9+
Cc: David Carrillo-Cisneros <davidcc@google.com>
---
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;
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] cgroup, perf_event: Fix perf cgroup hierarchy support
2017-10-28 16:49 [PATCH] cgroup, perf_event: Fix perf cgroup hierarchy support Tejun Heo
@ 2017-10-30 10:20 ` Peter Zijlstra
2017-10-30 11:26 ` [tip:perf/urgent] perf/cgroup: " tip-bot for Tejun Heo
1 sibling, 0 replies; 3+ messages in thread
From: Peter Zijlstra @ 2017-10-30 10:20 UTC (permalink / raw)
To: Tejun Heo
Cc: Ingo Molnar, Arnaldo Carvalho de Melo, linux-kernel,
David Carrillo-Cisneros, kernel-team, eranian
On Sat, Oct 28, 2017 at 09:49:37AM -0700, Tejun Heo wrote:
> 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.
Right similar to:
e6a5203399d1 ("perf/core: Fix cgroup time when scheduling descendants")
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Fixes: 864c2357ca89 ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups")
> Cc: stable@vger.kernel.org # v4.9+
> Cc: David Carrillo-Cisneros <davidcc@google.com>
I think David left Google (I've had this email bounce), lets add
Stephane.
Cc: Stephane Eranian <eranian@gmail.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> 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;
^ permalink raw reply [flat|nested] 3+ messages in thread
* [tip:perf/urgent] perf/cgroup: Fix perf cgroup hierarchy support
2017-10-28 16:49 [PATCH] cgroup, perf_event: Fix perf cgroup hierarchy support Tejun Heo
2017-10-30 10:20 ` Peter Zijlstra
@ 2017-10-30 11:26 ` tip-bot for Tejun Heo
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot for Tejun Heo @ 2017-10-30 11:26 UTC (permalink / raw)
To: linux-tip-commits
Cc: mingo, linux-kernel, acme, peterz, davidcc, torvalds, tglx, tj, hpa
Commit-ID: be96b316deff35e119760982c43af74e606fa143
Gitweb: https://git.kernel.org/tip/be96b316deff35e119760982c43af74e606fa143
Author: Tejun Heo <tj@kernel.org>
AuthorDate: Sat, 28 Oct 2017 09:49:37 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 30 Oct 2017 11:58:51 +0100
perf/cgroup: Fix perf cgroup hierarchy support
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 <tj@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel-team@fb.com
Cc: stable@vger.kernel.org # v4.9+
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 <mingo@kernel.org>
---
kernel/events/core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 9d93db8..10cdb9c 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -901,9 +901,11 @@ 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;
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2017-10-28 16:49 [PATCH] cgroup, perf_event: Fix perf cgroup hierarchy support Tejun Heo
2017-10-30 10:20 ` Peter Zijlstra
2017-10-30 11:26 ` [tip:perf/urgent] perf/cgroup: " tip-bot for Tejun Heo
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