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@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support  www.2ndQuadrant.us
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