The special file descriptor is opened via the perf_event_open()
system call:
- int sys_perf_event_open(struct perf_event_hw_event *hw_event_uptr,
+ int sys_perf_event_open(struct perf_event_attr *hw_event_uptr,
pid_t pid, int cpu, int group_fd,
unsigned long flags);
Multiple counters can be kept open at a time, and the counters
can be poll()ed.
-When creating a new counter fd, 'perf_event_hw_event' is:
+When creating a new counter fd, 'perf_event_attr' is:
-struct perf_event_hw_event {
+struct perf_event_attr {
/*
* The MSB of the config word signifies if the rest contains cpu
* specific (raw) counter configuration data, if unset, the next
fcntl() managing signals.
Normally a notification is generated for every page filled, however one can
-additionally set perf_event_hw_event.wakeup_events to generate one every
+additionally set perf_event_attr.wakeup_events to generate one every
so many counter overflow events.
Future work will include a splice() interface to the ring-buffer.