Re: Further reduction of bufmgr lock contention

Is this a TODO?

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Tom Lane wrote:
> Josh Berkus  writes:
> > BTW, we're going to be testing this patch on Sun Niagara servers.   What's 
> > the outstanding bug with it?   I don't quite follow.
> 
> It's not acceptable as-is because of the risk of running out of shared
> memory for hashtable entries.  In the existing code, there's a clear
> upper bound on the number of entries in the block-number-to-buffer hash
> table, ie, shared_buffers + 1 (the +1 because we acquire the new entry
> before releasing the old when reassigning a buffer).  With multiple
> hashtables serving subsets of the buffers, the different tables might
> at different times need different numbers of entries, and that makes it
> a lot harder to be sure you won't run out of memory.  I don't say it's
> insoluble, but the current patch wasn't even claimed to be safe by its
> author...
> 
> 			regards, tom lane
> 
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