Messages in this thread | | | Date | Wed, 7 Jan 2009 09:50:57 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: [PATCH -v4][RFC]: mutex: implement adaptive spinning |
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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
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