[EMAIL PROTECTED] wrote:
Quoting Kris Kennaway <[EMAIL PROTECTED]>:
[EMAIL PROTECTED] wrote:
Quoting Kris Kennaway <[EMAIL PROTECTED]>:
Michel Talon wrote:
On Mon, Jun 30, 2008 at 07:53:00PM +0200, Kris Kennaway wrote:
Yep, it could be that -- what confuses me though is that it is
claimed that performance suddenly regressed. If so then this
cannot be the underlying cause.
It may be that the load has augmented to the point that contention
imposes a rapid regression on throughput.
Yes, it could be that. I don't know off-hand whether multiple threads
are counted separately by vmstat (at a guess I'd say no), but
ps/top/etc
should show how many are active in the python process.
Just ran ktrace, and a bit of Googling seems to confirm my initial
suspicion that the results I'm seeing are abnormal. The first several
screenfulls of output look like this:
52929 python2.4 1214867016.469416 CALL kse_wakeup(0x811740c)
52929 python2.4 0.000060 RET kse_wakeup 0
52929 python2.4 0.000008 RET kse_release 0
52929 python2.4 0.000040 CALL kse_release(0x811df4c)
52929 python2.4 0.000515 CALL kse_wakeup(0x811740c)
52929 python2.4 0.000012 RET kse_wakeup 0
52929 python2.4 0.000004 RET kse_release 0
52929 python2.4 0.000012 CALL kse_release(0x811df4c)
52929 python2.4 0.000365 CALL kse_wakeup(0x811740c)
52929 python2.4 0.000012 RET kse_wakeup 0
52929 python2.4 0.000003 RET kse_release 0
52929 python2.4 0.000010 CALL kse_release(0x811df4c)
52929 python2.4 0.000413 CALL kse_wakeup(0x811740c)
52929 python2.4 0.000011 RET kse_wakeup 0
52929 python2.4 0.000004 RET kse_release 0
52929 python2.4 0.000009 CALL kse_release(0x811df4c)
52929 python2.4 0.000393 CALL kse_wakeup(0x811740c)
52929 python2.4 0.000012 RET kse_wakeup 0
52929 python2.4 0.000004 RET kse_release 0
52929 python2.4 0.000009 CALL kse_release(0x811df4c)
I may be mistaken, but it seems like that's a lot of unnecessary
activity managing the threads; the confirmation I found came from
http://arkiv.freebsd.se/?ml=freebsd-threads&a=2007-02&t=3178634.
Am I correct that this is abnormal behavior? If so, any idea what I
may need to do to fix the issue?
Looks exactly like the python thread problem Michel described.
You will get some improvement by switching to libthr and/or updating to
7.0 as I discussed, but ultimately you're hitting limits of python, not
FreeBSD.
WOW...it's *amazing* how much of a difference a single sysctl can make.
I went ahead and set kern.threads.virtual_cpu=1, as suggested in the
thread above, and the difference is ridiculous -- Zope is now faster
than I've ever seen. More importantly, my ktracing shows that all of the
kse_* garabage is now gone.
I'll probably be upgrading to 7.0 in the next month or so, given that
this is obviously a thread issue and that that release has much improved
thread code. However, for the time being, the pressing issue is fixed,
and for anyone in my position stuck on 6.2...this is night & day.
Seriously, try libthr. No matter what you do to libkse it is going to
suck. That's why we removed it.
Kris
_______________________________________________
freebsd-questions@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
