On Sunday 27 May 2007, Michael Buesch wrote: > On Sunday 27 May 2007 22:36:39 Maximilian Engelhardt wrote: > > When I ran 2.6.21.1 or 2.6.22-rc3 without any debugging tools just in > > normal use I didn't notice any problems. It did work fine as I would > > expect it. I think the wget and ping tests here are as they should be. > > > > With 2.6.22-rc2-mm1 I noticed that connections seem to be slower. The > > ping test does confirm this, because here response times are very high. > > As far as I can remember the wget download rate was a bit slower than > > 2.6.21.1 or 2.6.22-rc3 till it stalled. > > I would expect it to be someting like the other two kernels. The two > > problems I see are the high ping times and the fact that the card stopped > > working. > > > > I don't know why the iperf results are so different from my personal > > experience. I guess the fact that I get so bad results with 2.6.21.1 and > > 2.6.22-rc3 is that iperf does something that causes the system to be > > extremely slow and thus degrading performance. This could be a bug > > somewhere in the b44 driver of 2.6.21.1 and 2.6.22-RC3 that has > > unintended been fixed by the ssb switch, but that's only a roughly guess. > > Ok. I guess (Yes I do :D) that there is an IRQ storm or something like > that, because you say that your system is becoming very slow and > unresponsive. It sounds like an IRQ is not ACKed correctly and so keeps > triggering and stalling the system. I'll take a look at a few diffs... > Do you see significant differences in the "hi" and/or "si" times in top? > Do you see a significant difference in the /proc/interrupts count. For > example that the kernel that works worse generates 10 times the IRQ count > for the same amount of data. ok, here are the results: Using 2.6.22-rc3 I get lot's of hi during TX and lots of hi and si during RX. Using 2.6.22-rc3-mm1 hi and si are significantly lower. It's difficult to give absolute numbers, because top refreshes very slow, but with 2.6.22-rc3 hi is about 30% during TX and RX and si is 0% during TX and 50% during RX. With Using 2.6.22-rc3-mm1 hi is 0% during TX and 0.3% during RX and si is 10% during TX and 0% during RX. When I do the same test on both kernels I get about 10 times (yes, it's really about ten times like in your example) more interrupts with 2.6.22-rc3 than with 2.6.22-rc3-mm1. An additional thing I noticed it that it's not the BCM4401 card that stops working but my e100 card. If I take the e100 card down and up again the connection is working again, so the BCM4401 doesn't have a "stops working" bug for me. Maxi
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