Context Switching issue: Spinlock doesn't fix.

Folks,

I've been testing varying SPINS_PER_DELAY in a client's installation of
PostgreSQL against a copy of a production database, to test varying this
statistic as a way of fixing the issue.

It does not seem to work.

I've tested all of the following graduated levels:

100 (the original)
250
500
1000
2000
5000
10000
20000
30000
50000

None of these quantities seem to make any difference at all in the number of
context switches -- neither down nor up.   Seems to me like this is a dead
end.   Does anyone have test results that show otherwise?

--
-Josh Berkus
 Aglio Database Solutions
 San Francisco