Messages in this thread | | | Date | Sat, 16 Oct 2010 18:57:03 +1100 | From | Nick Piggin <> | Subject | Re: [PATCH 11/18] fs: Introduce per-bucket inode hash locks |
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On Fri, Oct 08, 2010 at 02:54:09PM -0400, Christoph Hellwig wrote: > > +struct inode_hash_bucket { > > + struct hlist_bl_head head; > > +}; > > + > > +static inline void spin_lock_bucket(struct inode_hash_bucket *b) > > +{ > > + bit_spin_lock(0, (unsigned long *)b); > > +} > > + > > +static inline void spin_unlock_bucket(struct inode_hash_bucket *b) > > +{ > > + __bit_spin_unlock(0, (unsigned long *)b); > > +} > > I've looked at the dcache version of this again, and I really hate > duplicating these helpers in the dcache code aswell. IMHO they > should simple operate directly on the hlist_bl_head, as that's > what it was designed for. I also don't really see any point in > wrapping the hlist_bl_head as inode_hash_bucket. If the bucket naming > is important we could rename the hlist_bl stuff to bl_hash, and the > hlist_bl_head could become bl_hash_bucket.
It was done because someone, like -rt, might want more than one bit of memory to implement a lock. They would have to make a few other changes, granted, but this helps reduce a lot of churn.
I didn't see the point of a layer of dumb wrappers for hlist_bl_head locking. Just reproducing bit spin and wait locks in wrappers when we already have good functions for them.
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