Re: Scaling shared buffer eviction

On 2014-09-25 10:22:47 -0400, Robert Haas wrote:
> On Thu, Sep 25, 2014 at 10:14 AM, Andres Freund <andres@2ndquadrant.com> wrote:
> > That leads me to wonder: Have you measured different, lower, number of
> > buffer mapping locks? 128 locks is, if we'd as we should align them
> > properly, 8KB of memory. Common L1 cache sizes are around 32k...
> 
> Amit has some results upthread showing 64 being good, but not as good
> as 128.  I haven't verified that myself, but have no reason to doubt
> it.

How about you push the spinlock change and I crosscheck the partition
number on a multi socket x86 machine? Seems worthwile to make sure that
it doesn't cause problems on x86. I seriously doubt it'll, but ...

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
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