Re: [PATCH/RFC 12/16] perf tools: Reduce lock contention when processing events

From: Jiri Olsa
Date: Mon Dec 14 2015 - 03:43:20 EST

On Thu, Dec 10, 2015 at 04:53:31PM +0900, Namhyung Kim wrote:
> When multi-thread is enabled, the machine->threads_lock is contented
> as all worker threads try to grab the writer lock using the
> machine__findnew_thread(). Usually, the thread they're looking for is
> in the tree so they only need the reader lock though.
> Thus try machine__find_thread() first, and then fallback to the
> 'findnew' API. This will improve the performance.

found one other place, but I guess you chose those
based on profiling the contention?

parent lookup in machine__process_fork_event

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at