Re: [PATCHES] update i386 spinlock for hyperthreading

Jan Wieck wrote:
> Manfred Spraul wrote:
> > Bruce Momjian wrote:
> >
> >>>Anyone see an attack path here?
> >>>
> >>>
> >>
> >>Should we have one lock per hash bucket rather than one for the entire
> >>hash?
> >>
> >>
> > That's the simple part. The problem is the aging strategy: we need a
> > strategy that doesn't rely on a global list that's updated after every
> > lookup. If I understand the ARC code correctly, there is a
> > STRAT_MRU_INSERT(cdb, STRAT_LIST_T2) that happen in every lookup.
>
> Moving the Cache Directory Block (cdb) on a hit to the MRU position of
> the appropriate queue "is the bookkeeping" of this strategy. The whole
> algorithm is based on it, and I don't see yet how to avoid that without
> opening a huge can of worms that look like deadlocks. But I'll think
> about it for a while.

If we can't eliminate the global lock, and we reduce its duration?

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