perf: Add cgroup support

This kernel patch adds the ability to filter monitoring based on
container groups (cgroups). This is for use in per-cpu mode only.

The cgroup to monitor is passed as a file descriptor in the pid
argument to the syscall. The file descriptor must be opened to
the cgroup name in the cgroup filesystem. For instance, if the
cgroup name is foo and cgroupfs is mounted in /cgroup, then the
file descriptor is opened to /cgroup/foo. Cgroup mode is
activated by passing PERF_FLAG_PID_CGROUP in the flags argument
to the syscall.

For instance to measure in cgroup foo on CPU1 assuming
cgroupfs is mounted under /cgroup:

struct perf_event_attr attr;
int cgroup_fd, fd;

cgroup_fd = open("/cgroup/foo", O_RDONLY);
fd = perf_event_open(&attr, cgroup_fd, 1, -1, PERF_FLAG_PID_CGROUP);
close(cgroup_fd);

Signed-off-by: Stephane Eranian <eranian@google.com>
[ added perf_cgroup_{exit,attach} ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4d590250.114ddf0a.689e.4482@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 10 insertions, 0 deletions

diff --git a/init/Kconfig b/init/Kconfig
index be788c0957d4..20d6bd919b8d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -683,6 +683,16 @@ config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
           select this option (if, for some reason, they need to disable it
           then noswapaccount does the trick).
 
+config CGROUP_PERF
+        bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
+        depends on PERF_EVENTS && CGROUPS
+        help
+          This option extends the per-cpu mode to restrict monitoring to
+          threads which belong to the cgroup specificied and run on the
+          designated cpu.
+
+          Say N if unsure.
+
 menuconfig CGROUP_SCHED
         bool "Group CPU scheduler"
         depends on EXPERIMENTAL