Commit 79dff51e authored by Matt Fleming's avatar Matt Fleming Committed by Ingo Molnar
Browse files

perf: Move cgroup init before PMU ->event_init() 



The Intel QoS PMU needs to know whether an event is part of a cgroup
during ->event_init(), because tasks in the same cgroup share a
monitoring ID.

Move the cgroup initialisation before calling into the PMU driver.

Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kanaka Juvva <kanaka.d.juvva@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Link: http://lkml.kernel.org/r/1422038748-21397-4-git-send-email-matt@codeblueprint.co.uk


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent eacd3ecc

kernel/events/core.c

+16 −12
Original line number Diff line number Diff line
@@ -7116,7 +7116,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, 
		 struct perf_event *group_leader,

		 struct perf_event *parent_event,

		 perf_overflow_handler_t overflow_handler,

		 void *context)

		 void *context, int cgroup_fd)

{

	struct pmu *pmu;

	struct perf_event *event;
@@ -7212,6 +7212,12 @@ 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 (!pmu)

		goto err_ns;
@@ -7235,6 +7241,8 @@ err_pmu: 
		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);

	kfree(event);
@@ -7453,6 +7461,7 @@ SYSCALL_DEFINE5(perf_event_open, 
	int move_group = 0;

	int err;

	int f_flags = O_RDWR;

	int cgroup_fd = -1;



	/* for future expandability... */

	if (flags & ~PERF_FLAG_ALL)
@@ -7518,21 +7527,16 @@ SYSCALL_DEFINE5(perf_event_open, 


	get_online_cpus();



	if (flags & PERF_FLAG_PID_CGROUP)

		cgroup_fd = pid;



	event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,

				 NULL, NULL);

				 NULL, NULL, cgroup_fd);

	if (IS_ERR(event)) {

		err = PTR_ERR(event);

		goto err_cpus;

	}



	if (flags & PERF_FLAG_PID_CGROUP) {

		err = perf_cgroup_connect(pid, event, &attr, group_leader);

		if (err) {

			__free_event(event);

			goto err_cpus;

		}

	}



	if (is_sampling_event(event)) {

		if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {

			err = -ENOTSUPP;
@@ -7769,7 +7773,7 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, 
	 */



	event = perf_event_alloc(attr, cpu, task, NULL, NULL,

				 overflow_handler, context);

				 overflow_handler, context, -1);

	if (IS_ERR(event)) {

		err = PTR_ERR(event);

		goto err;
@@ -8130,7 +8134,7 @@ inherit_event(struct perf_event *parent_event, 
					   parent_event->cpu,

					   child,

					   group_leader, parent_event,

				           NULL, NULL);

					   NULL, NULL, -1);

	if (IS_ERR(child_event))

		return child_event;

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