Re: Review: compact fsync request queue on overflow

Chris Browne wrote:
> It was a little troublesome inducing it. I did so by cutting
> shared memory to minimum (128kB)...
> With higher shared memory, I couldn't readily induce compaction,
> which is probably a concurrency matter of not having enough volume
> of concurrent work going on.
>

Quite. It's taken me 12 days of machine time running pgbench to find
the spots where this problem occurs on a system with a reasonably sized
shared_buffers (I'm testing against 256MB). It's one of those things
it's hard to reproduce with test data.

Thanks for the thorough code review. I've got a clear test plan I'm
progressing through this week to beat on the performance measurement
aspects of the patch.

--
Greg Smith 2ndQuadrant US greg(at)2ndQuadrant(dot)com Baltimore, MD
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