Re: stuck spin lock with many concurrent users
От | Bruce Momjian |
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Тема | Re: stuck spin lock with many concurrent users |
Дата | |
Msg-id | 200107040104.f6414Oc09400@candle.pha.pa.us обсуждение исходный текст |
Ответ на | Re: stuck spin lock with many concurrent users (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: stuck spin lock with many concurrent users
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Список | pgsql-hackers |
> Yes, it sure is, but remember that the guy getting useful work done > (DeadLockCheck) is having to share the CPU with 999 other processes > that are waking up on every clock tick for just long enough to fail > to get the spinlock. I think it's those useless process wakeups that > are causing the problem. > > If you estimate that a process dispatch cycle is ~ 10 microseconds, > then waking 999 useless processes every 10 msec is just about enough > to consume 100% of the CPU doing nothing useful... so what should be > a few-millisecond check takes a long time, which makes things worse > because the 999 wannabees are spinning for that much more time. Don't we back off the sleeps or was that code removed? -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
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