Messages in this thread | | | Date | Fri, 9 Jan 2009 19:40:48 +0100 | From | Joerg Roedel <> | Subject | Re: [PATCH 03/16] dma-debug: add hash functions for dma_debug_entries |
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On Fri, Jan 09, 2009 at 09:23:39PM +0300, Evgeniy Polyakov wrote: > On Fri, Jan 09, 2009 at 07:14:46PM +0100, Joerg Roedel (joro@8bytes.org) wrote: > > > > +static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry, > > > > + unsigned long *flags) > > > > +{ > > > > + int idx = hash_fn(entry); > > > > + unsigned long __flags; > > > > + > > > > + spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags); > > > > + *flags = __flags; > > > > + return &dma_entry_hash[idx]; > > > > +} > > > > + > > > > +/* > > > > + * Give up exclusive access to the hash bucket > > > > + */ > > > > +static void put_hash_bucket(struct hash_bucket *bucket, > > > > + unsigned long *flags) > > > > +{ > > > > + unsigned long __flags = *flags; > > > > + > > > > + spin_unlock_irqrestore(&bucket->lock, __flags); > > > > +} > > > > > > Why do you need such ugly helpers? > > > > Because everything else I thought about here was even more ugly. But > > maybe you have a better idea? I tried to lock directly in the debug_ > > functions. But this is ugly and unnecessary code duplication. > > I believe that having direct locking in the debug_ functions is not a > duplication, anyone will have a direct vision on the locking and hash > array dereference, and this will be just one additional line compared to > the get_* call and the same number of lines for the put :)
Even more additional lines because of the additional variables needed in every function. Anyway, I try it and if it does not look good I will keep that change ;)
Joerg
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