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| author | Tejun Heo <tj@kernel.org> | 2013-04-08 19:00:38 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2013-04-10 11:07:16 -0700 |
| commit | ef824fa129b7579f56b92d466ecda2e378879806 (patch) | |
| tree | 4a0e244bae94fffd4cc37d5ddaa73edad3fa2882 | |
| parent | 78574cf981cd3d9ae9f6adbd466a772310ec24ff (diff) | |
| download | linux-ef824fa129b7579f56b92d466ecda2e378879806.tar.gz linux-ef824fa129b7579f56b92d466ecda2e378879806.tar.bz2 linux-ef824fa129b7579f56b92d466ecda2e378879806.zip | |
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>
| -rw-r--r-- | kernel/events/core.c | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index b0cd86501c30..310ec19d968a 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 */ |