On Wed, 7 Jan 2009, Chris Mason wrote: > > So far I haven't found any btrfs benchmarks where this is slower than > mutexes without any spinning. But, it isn't quite as fast as the btrfs > spin. Quite frankly, from our history with ext3 and other filesystems, using a mutex in the filesystem is generally the wrong thing to do anyway. Are you sure you can't just use a spinlock, and just release it over IO? The "have to do IO or extend the btree" case is usually pretty damn clear. Because it really sounds like you're lock-limited, and you should just try to clean it up. A pure "just spinlock" in the hotpath is always going to be better. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
