Re: perf for analyzing userspace contention

[David Ahern <dsahern@xxxxxxxxx>]

On 10/14/2011 12:36 AM, Roland Dreier wrote:
> Anyway, suppose I have a multithreaded userspace app that uses a bunch of
> pthread_mutexes, and I want to figure out which locks are hot and/or heavily
> contended.  What's the best way to do that?  Is perf the right, or is there
> something better?  (This seems like such an obvious thing to want that there
> must be some good way to get this data, I hope)

You can capture futex entry and exit with:

perf trace -e syscalls:sys_enter_futex -e syscalls:sys_exit_futex

add -g to get the callchains. From there perf-script will dump the events.

David
--
To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html