----- On Jul 13, 2015, at 7:17 AM, Ben Maurer bmaurer@xxxxxx wrote: > At Facebook we already use getcpu in folly, our base C++ library, to provide > high performance concurrency algorithms. Folly includes an abstraction called > AccessSpreader which helps engineers write abstractions which shard themselves > across different cores to prevent cache contention > (https://github.com/facebook/folly/blob/master/folly/detail/CacheLocality.cpp). > We have used this primative to create faster reader writer locks > (https://github.com/facebook/folly/blob/master/folly/SharedMutex.h), as well as > in an abstraction that powers workqueues > (https://github.com/facebook/folly/blob/master/folly/IndexedMemPool.h). This > would be a great perf improvement for these types of abstractions and probably > encourage us to use the idea more widely. > > One quick comment on the approach -- it'd be really great if we had a method > that didn't require users to register each thread. This can often lead to > requiring an additional branch in critical code to check if the appropriate > caches have been initialized. Also, one of the most interesting potential > applications of the restartable sequences concept is in malloc. having a brief > period at the beginning of the life of a thread where malloc didn't work would > be pretty tricky to program around. If we invoke this per-thread registration directly in the glibc NPTL implementation, in start_thread, do you think it would fit your requirements ? Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
