Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [patch 00/52] vfs scalability patches updated | Date | Thu, 01 Jul 2010 19:36:45 +0200 |
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Dave Chinner <david@fromorbit.com> writes: > > I'm not denying it that we need to do work here - I'm questioning > the "change everything at once" approach this patch set takes. > You've started from the assumption that everything the dcache_lock > and inode_lock protect are a problem and goes from there.
Global code locks in a core subsystem are definitely a problem.
In many ways they're as bad a a BKL. There will be always workloads where they hurt. They are bad coding style. They just have to go.
I don't understand how anyone can even defend them.
Especially bad are code locks that protect lots of different things. Those are not only bad for scalability, but also bad for maintainability, because few people can really understand them even. With smaller well defined locks that's usually easier.
-Andi
-- ak@linux.intel.com -- Speaking for myself only.
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