Re: Poor thread performance on Linux vs. Solaris
Dan Kegel <[email protected]>
| Newsgroups | gmane.comp.lib.phil |
|---|---|
| Message-ID | <[email protected]> |
Bill Soudan wrote: > I've recently ported a heavily multithreaded application from Solaris to > Linux, but upon running performance tests, I'm encountering some serious > issues on a 4 way 2.8GHz Xeon box running RedHat 9. ... > > Both Intel's vtune tool and oprofile reveal the majority of the time is > spent in '.text.lock.futex', which after some research, I believe is code > that implements a spinlock for the 'futex' lock in kernel/futex.c. The > logical conclusion follows that the system time represents the CPUs > wasting their time spinning while waiting for the lock. > > Now my question is, how should I proceed? The same app scales fine on > Solaris, chewing up 100% user time of every CPU I can throw at it. We would of course love it if you could post a small test program that reproduced the problem. Any chance that's possible? - Dan -- Dan Kegel http://www.kegel.com http://counter.li.org/cgi-bin/runscript/display-person.cgi?user=78045