Re: Wierd context-switching issue on Xeon patch for 7.4.1

Поиск
Список
Период
Сортировка
От Dave Cramer
Тема Re: Wierd context-switching issue on Xeon patch for 7.4.1
Дата
Msg-id 1083090452.14759.224.camel@localhost.localdomain
обсуждение исходный текст
Ответ на Re: Wierd context-switching issue on Xeon patch for 7.4.1  (Josh Berkus <josh@agliodbs.com>)
Ответы Re: Wierd context-switching issue on Xeon patch for 7.4.1  (Josh Berkus <josh@agliodbs.com>)
Список pgsql-performance
Josh,

I think you can safely increase by orders of magnitude here, instead of
by +100, my wild ass guess is that the sweet spot is the spin time
should be approximately the time it takes to consume the resource. So if
you have a really fast machine then the spin count should be higher.

Also you have to take into consideration your memory bus speed, with the
pause instruction inserted in the loop the timing is now dependent on
memory speed.

But... you need a baseline first.

Dave
On Tue, 2004-04-27 at 14:05, Josh Berkus wrote:
> Dave,
>
> > Are you testing this with Tom's code, you need to do a baseline
> > measurement with 10 and then increase it, you will still get lots of cs,
> > but it will be less.
>
> No, that was just a test of 1000 straight up.    Tom outlined a method, but I
> didn't see any code that would help me find a better level, other than just
> trying each +100 increase one at a time.   This would take days of testing
> ...
--
Dave Cramer
519 939 0336
ICQ # 14675561


В списке pgsql-performance по дате отправления:

Предыдущее
От: Josh Berkus
Дата:
Сообщение: Re: Wierd context-switching issue on Xeon patch for 7.4.1
Следующее
От: Josh Berkus
Дата:
Сообщение: Re: Wierd context-switching issue on Xeon patch for 7.4.1