Re: futex results with dbt-3 - Mailing list pgsql-performance

From Gaetano Mendola
Subject Re: futex results with dbt-3
Date
Msg-id 417A37BB.9050305@bigfoot.com
Whole thread Raw
In response to Re: futex results with dbt-3  (Josh Berkus <josh@agliodbs.com>)
Responses Re: futex results with dbt-3
List pgsql-performance
Josh Berkus wrote:
 > Tom,
 >
 >
 >>The bigger problem here is that the SMP locking bottlenecks we are
 >>currently seeing are *hardware* issues (AFAICT anyway).  The only way
 >>that futexes can offer a performance win is if they have a smarter way
 >>of executing the basic atomic-test-and-set sequence than we do;
 >>and if so, we could read their code and adopt that method without having
 >>to buy into any large reorganization of our code.
 >
 >
 > Well, initial results from Gavin/Neil's patch seem to indicate that, while
 > futexes do not cure the CSStorm bug, they do lessen its effects in terms of
 > real performance loss.

I proposed weeks ago to see how the CSStorm is affected by stick each backend
in one processor ( where the process was born ) using the cpu-affinity capability
( kernel 2.6 ), is this proposal completely out of mind ?


Regards
Gaetano Mendola








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