aboutsummaryrefslogtreecommitdiff
path: root/kernel/events
diff options
context:
space:
mode:
authorTejun Heo <tj@kernel.org>2013-04-08 19:00:38 -0700
committerTejun Heo <tj@kernel.org>2013-04-10 11:07:16 -0700
commitef824fa129b7579f56b92d466ecda2e378879806 (patch)
tree4a0e244bae94fffd4cc37d5ddaa73edad3fa2882 /kernel/events
parent78574cf981cd3d9ae9f6adbd466a772310ec24ff (diff)
downloadvexpress-lsk-ef824fa129b7579f56b92d466ecda2e378879806.tar.gz
perf: make perf_event cgroup hierarchical
perf_event is one of a couple remaining cgroup controllers with broken hierarchy support. Converting it to support hierarchy is almost trivial. The only thing necessary is to consider a task belonging to a descendant cgroup as a match. IOW, if the cgroup of the currently executing task (@cpuctx->cgrp) equals or is a descendant of the event's cgroup (@event->cgrp), then the event should be enabled. Implement hierarchy support and remove .broken_hierarchy tag along with the incorrect comment on what needs to be done for hierarchy support. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Stephane Eranian <eranian@google.com> Cc: Namhyung Kim <namhyung.kim@lge.com>
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c24
1 files changed, 16 insertions, 8 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index b0cd86501c3..310ec19d968 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -251,7 +251,22 @@ perf_cgroup_match(struct perf_event *event)
struct perf_event_context *ctx = event->ctx;
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
- return !event->cgrp || event->cgrp == cpuctx->cgrp;
+ /* @event doesn't care about cgroup */
+ if (!event->cgrp)
+ return true;
+
+ /* wants specific cgroup scope but @cpuctx isn't associated with any */
+ if (!cpuctx->cgrp)
+ return false;
+
+ /*
+ * Cgroup scoping is recursive. An event enabled for a cgroup is
+ * also enabled for all its descendant cgroups. If @cpuctx's
+ * cgroup is a descendant of @event's (the test covers identity
+ * case), it's a match.
+ */
+ return cgroup_is_descendant(cpuctx->cgrp->css.cgroup,
+ event->cgrp->css.cgroup);
}
static inline bool perf_tryget_cgroup(struct perf_event *event)
@@ -7509,12 +7524,5 @@ struct cgroup_subsys perf_subsys = {
.css_free = perf_cgroup_css_free,
.exit = perf_cgroup_exit,
.attach = perf_cgroup_attach,
-
- /*
- * perf_event cgroup doesn't handle nesting correctly.
- * ctx->nr_cgroups adjustments should be propagated through the
- * cgroup hierarchy. Fix it and remove the following.
- */
- .broken_hierarchy = true,
};
#endif /* CONFIG_CGROUP_PERF */