perf/core: Add PERF_RECORD_CGROUP event

To support cgroup tracking, add CGROUP event to save a link between
cgroup path and id number.  This is needed since cgroups can go away
when userspace tries to read the cgroup info (from the id) later.

The attr.cgroup bit was also added to enable cgroup tracking from
userspace.

This event will be generated when a new cgroup becomes active.
Userspace might need to synthesize those events for existing cgroups.

Committer testing:

From the resulting kernel, using /sys/kernel/btf/vmlinux:

  $ pahole perf_event_attr | grep -w cgroup -B5 -A1
  	__u64                      write_backward:1;     /*    40:27  8 */
  	__u64                      namespaces:1;         /*    40:28  8 */
  	__u64                      ksymbol:1;            /*    40:29  8 */
  	__u64                      bpf_event:1;          /*    40:30  8 */
  	__u64                      aux_output:1;         /*    40:31  8 */
  	__u64                      cgroup:1;             /*    40:32  8 */
  	__u64                      __reserved_1:31;      /*    40:33  8 */
  $

Reported-by: kbuild test robot <[email protected]>
Signed-off-by: Namhyung Kim <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Tejun Heo <[email protected]>
[staticize perf_event_cgroup function]
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Zefan Li <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions