Date: Sun, 7 Dec 2003 21:59:36 -0500 From: "Christopher M. Sedore" <cmsedore@maxwell.syr.edu> To: "David Xu" <davidxu@freebsd.org> Cc: threads@freebsd.org Subject: RE: KSE system scope vs non system scope threads Message-ID: <32A8B2CB12BFC84D8D11D872C787AA9A02B1F7D9@EXCHANGE.forest.maxwell.syr.edu>
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Sorry for the long delay in responding. We upgraded to 5.2Beta before = we did this trial, and after installing on our SMP machines (that's all = we've been using for tests), we haven't been able to get them stable--we = see panics within 15 minutes of boot once our threaded process begins. = To continue testing, we rebuilt the kernel uniproc. The change back to = v1.18 of thr_spinlock improves the situation but we're still seeing some = degradation, but it is shorter and shallower now than it was. I need to = do more thorough testing before I can claim that it is related to a KSE = issue--it could be some other performance oddity. =20 (I'm not approaching any of the kernel limits. I'm peaking around 30-40 = threads.) =20 As a side-note, could anyone offer any ideas as to why I'm getting an = error EAGAIN from sendfile when not using non-blocking sockets? As far = as I could determine, the only case where I should see EAGAIN is a NB = socket. I'm seeing this happen part way through a send (200k into a = 500k send in one instance). I'm expecting to have to set up a kernel = debugger to trace it out since a scan of the kernel source doesn't show = any simple reason why this might happen. =20 -Chris ________________________________ From: David Xu [mailto:davidxu@freebsd.org] Sent: Sun 11/30/2003 6:25 PM To: Christopher M. Sedore Cc: deischen@freebsd.org; threads@freebsd.org Subject: Re: KSE system scope vs non system scope threads Christopher M. Sedore wrote: >I'm using blocking connects. Degradation is I should be moving = ~5-7MB/sec (and I do if I don't try to connect to any hosts that are = down). Once I do, I see fluctuations from ~15-20KB/sec (note: KB) to = 3-5MB/sec, somewhat associated with when the connects happen. Running = libthr, I move 6-7MB/sec consistently (until everything hangs up showing = sigwait as the status in top, anyway). System scope threads turn in = numbers from 5-6MB/sec. (Note I don't have any hang problems under KSE, = only libthr.) > >On Monday I'm going to try David Xu's suggestion of trying v1.18 of = thr_spinlock.c to see if that helps. > >=20 > I don't know if you hit a hard limit in kernel. The hard limit is sysctl kern.threads.max_threads_per_proc, default is 150, it means system only allows 150 threads to be blocked in kernel, if you hit the limits, then performance will be degraded. David Xu >-Chris >_______________________________________________ >freebsd-threads@freebsd.org mailing list >http://lists.freebsd.org/mailman/listinfo/freebsd-threads >To unsubscribe, send any mail to = "freebsd-threads-unsubscribe@freebsd.org" > >=20 >
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