Messages in this thread | | | Date | Fri, 6 Feb 2009 15:34:14 +1100 | From | Paul Mackerras <> | Subject | Re: [PATCH] perf_counter: Prevent oopses from per-cpu software counters |
| |
Ingo Molnar writes:
> So how about fixing these sw counts to properly work as percpu counters too?
OK, so for page faults it looks like I want to look at
get_cpu_var(vm_event_states).event[PGFAULT]
to get the per-cpu page fault count, as long as CONFIG_VM_EVENT_COUNTERS is set.
It looks like the scheduler doesn't keep per-cpu counts of context switches or task migrations, or if it does I couldn't find them. We could do stuff in perf_counter_task_sched_in/out to implement per-cpu context switch and migration counters by adding up the delta values for each task that gets scheduled onto the cpu. Or we could add explicit per-cpu counters for these things in the scheduler.
What do you think?
Paul.
| |