Re: [PATCHES] update i386 spinlock for hyperthreading

Tom Lane wrote:
> Jan Wieck <JanWieck@Yahoo.com> writes:
> >> That's irrelevant to the problem, though.  Unless the ARC code uses data
> >> structures that are more amenable to localized locking than the old
> >> global buffer freelist.  (Jan?)
> 
> > the strategy itself does no locking at all. Like the old LRU code it 
> > simply assumes that the buffer manager holds the lock during calls.
> 
> Okay, I suspected as much but wasn't sure.
> 
> Manfred's numbers definitely say that we need to find a way to break
> down the BufMgrLock into multiple finer-grain locks.  We already have
> all those per-buffer LWLocks, but I don't see how to apply those to
> the problem of managing the global lookup and replacement datastructures.
> 
> Anyone see an attack path here?

Should we have one lock per hash bucket rather than one for the entire
hash?

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
Pennsylvania19073