[tip: perf/core] perf/cgroup: Reorder perf_cgroup_connect()

[tip-bot2 for Peter Zijlstra]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     98add2af89bbfe8241e189b490fd91e5751c7900
Gitweb:        https://git.kernel.org/tip/98add2af89bbfe8241e189b490fd91e5751c7900
Author:        Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate:    Thu, 13 Feb 2020 23:51:28 -08:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Fri, 06 Mar 2020 11:56:58 +01:00

perf/cgroup: Reorder perf_cgroup_connect()

Move perf_cgroup_connect() after perf_event_alloc(), such that we can
find/use the PMU's cpu context.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200214075133.181299-2-irogers@xxxxxxxxxx
---
 kernel/events/core.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index b7eaaba..dceeeb1 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10774,12 +10774,6 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
 	if (!has_branch_stack(event))
 		event->attr.branch_sample_type = 0;
 
-	if (cgroup_fd != -1) {
-		err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
-		if (err)
-			goto err_ns;
-	}
-
 	pmu = perf_init_event(event);
 	if (IS_ERR(pmu)) {
 		err = PTR_ERR(pmu);
@@ -10801,6 +10795,12 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
 		goto err_pmu;
 	}
 
+	if (cgroup_fd != -1) {
+		err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
+		if (err)
+			goto err_pmu;
+	}
+
 	err = exclusive_event_init(event);
 	if (err)
 		goto err_pmu;
@@ -10861,12 +10861,12 @@ err_per_task:
 	exclusive_event_destroy(event);
 
 err_pmu:
+	if (is_cgroup_event(event))
+		perf_detach_cgroup(event);
 	if (event->destroy)
 		event->destroy(event);
 	module_put(pmu->module);
 err_ns:
-	if (is_cgroup_event(event))
-		perf_detach_cgroup(event);
 	if (event->ns)
 		put_pid_ns(event->ns);
 	if (event->hw.target)