On Fri, 24 Oct 2014, Peter Zijlstra wrote: > The hold time isn't relevant, in fact breaking up the mmap_sem such that > we require multiple acquisitions will just increase the cacheline > bouncing.
Well this wont be happening anymore once you RCUify the stuff. If you go to sleep then its best to release mmap_sem and then the bouncing wont matter. Dropping mmap_sem there will also expose you to races you will see later too when you RCUify the code paths. That way those can be deal with beforehand. > Also I think it makes more sense to continue an entire fault operation, > including blocking, if at all possible. Every retry will just waste more > time. Ok then dont retry. Just drop mmap_sem before going to sleep. When you come back evaluate the situation and if we can proceed do so otherwise retry. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
