diff options
Diffstat (limited to 'include/linux/perf_event.h')
| -rw-r--r-- | include/linux/perf_event.h | 42 |
1 files changed, 40 insertions, 2 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 52dc7cfab0e0..ec9d96025683 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -635,8 +635,46 @@ struct perf_addr_filter_range { unsigned long size; }; -/** - * enum perf_event_state - the states of an event: +/* + * The normal states are: + * + * ACTIVE --. + * ^ | + * | | + * sched_{in,out}() | + * | | + * v | + * ,---> INACTIVE --+ <-. + * | | | + * | {dis,en}able() + * sched_in() | | + * | OFF <--' --+ + * | | + * `---> ERROR ------' + * + * That is: + * + * sched_in: INACTIVE -> {ACTIVE,ERROR} + * sched_out: ACTIVE -> INACTIVE + * disable: {ACTIVE,INACTIVE} -> OFF + * enable: {OFF,ERROR} -> INACTIVE + * + * Where {OFF,ERROR} are disabled states. + * + * Then we have the {EXIT,REVOKED,DEAD} states which are various shades of + * defunct events: + * + * - EXIT means task that the even was assigned to died, but child events + * still live, and further children can still be created. But the event + * itself will never be active again. It can only transition to + * {REVOKED,DEAD}; + * + * - REVOKED means the PMU the event was associated with is gone; all + * functionality is stopped but the event is still alive. Can only + * transition to DEAD; + * + * - DEAD event really is DYING tearing down state and freeing bits. + * */ enum perf_event_state { PERF_EVENT_STATE_DEAD = -5, |