Messages in this thread | | | Date | Sun, 28 Sep 2008 12:58:34 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [Bug #11516] severe performance degradation on x86_64 going from 2.6.26-rc9 -> 2.6.27-rc5 |
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On Sun, 28 Sep 2008, Jason Vas Dias wrote: > The problem is not "slow booting" - indeed, as noted in the bug, boot time up to the point > where user space should start is very similar to the non-problematic 2.6.26 kernels. > > The USB problem is that @ 10 messages per second are emitted to the log: > Sep 28 00:41:51 localhost kernel: [ 11.985257] hub 3-0:1.0: state 7 ports 2 chg 0000 evt 0002 > Sep 28 00:41:51 localhost kernel: [ 12.789240] hub 1-0:1.0: state 7 ports 2 chg 0000 evt 0004 > Sep 28 00:41:51 localhost kernel: [ 12.937169] hub 4-0:1.0: state 7 ports 2 chg 0000 evt 0000 > Sep 28 00:41:51 localhost kernel: [ 12.937188] hub 3-0:1.0: state 7 ports 2 chg 0000 evt 0002 > Sep 28 00:41:51 localhost kernel: [ 13.041167] hub 5-0:1.0: state 7 ports 2 chg 0000 evt 0000 > Sep 28 00:41:51 localhost kernel: [ 13.041186] hub 6-0:1.0: state 7 ports 10 chg 0000 evt 0000 > Sep 28 00:41:51 localhost kernel: [ 13.453734] hub 6-0:1.0: state 7 ports 10 chg 0000 evt 0020 > Sep 28 00:41:51 localhost kernel: [ 13.453748] hub 1-0:1.0: state 7 ports 2 chg 0000 evt 0004 > Sep 28 00:41:51 localhost kernel: [ 13.846512] hub 3-0:1.0: state 7 ports 2 chg 0000 evt 0002 > Sep 28 00:41:51 localhost kernel: [ 14.220994] hub 3-0:1.0: state 7 ports 2 chg 0000 evt 0002 > > Why should USB be emitting state change messages when no state has changed ?
That's a separate question.
> I think this is because the core PM-timer (clocksource is acpi-pm) is kaput , > and every driver that depends on high-resolution timers gets confused .
No, if the pmtimer would be defect your machine would not even reach user space.
I analysed the proc/acpi data of .25 and .27 and the machine is set to throttling state T7 (12%) which would explain that behaviour halfways.
Can you please verify if that state is always T7 on your machine with .27 ?
Also please add "acpi.debug_level=0x11" to the kernel command line so we can get some more information out of the ACPI code.
> Displaying text on the terminal is @ 140 times slower under 2.6.27 > kernels than under 2.6.26 kernels . Downloads over the network take > @ 1000 times longer under 2.6.27 than under 2.6.26. Disk I/O is @ > 100 times slower.
That's indeed insane.
> There are numerous log messages about "interrupt during system call" > (EINTR) from user-space processes.
Separate problem as well.
Please let us concentrate on the throttling aspect and not mix USB/EINTR stuff into it for now.
Thanks,
tglx
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