On Thu, 14 Mar 2013, Alan Stern wrote: > > > Can you try to do a git bisect for this? Is the sluggish system > > > response clear enough that you can tell reliably when it is present and > > > when it isn't? > > > > That was my first thought, but unfortunately I am afraid there will be > > point at which I will easily make a bisection mistake, as the > > responsiveness of the system varies over time, so it's not really a > > 100% objective measure. > > All right. > > There have been only three significant changes to uhci-hcd since last > summer, and two of them appear to be completely unrelated to this > issue. The three commits are > > 3171fcabb169 USB: uhci: beautify source code > 13996ca7afd5 USB: uhci: check buffer length to avoid memory > overflow > 0f815a0a700b USB: UHCI: fix IRQ race during initialization > > Reverting the first two almost certainly will not have any effect, but > you may as well try it anyway. The third commit may be relevant. I have reverted all three commits, and the "nobody cared" is still there. > If you revert all three and still see the problem then it must be > caused by changes outside of the USB stack. Differences in interrupt > routing could be a result of changes to PCI or ACPI. Have you compared > the current /proc/interrupts with versions from earlier kernels without > this problem? The diff of stripped-down (without CPU statistics) /proc/interrupts from some oldish working 3.1 and the current tree: --- /tmp/interrupts-old.txt 2013-03-14 16:30:46.938710286 +0100 +++ /tmp/interrupts-new.txt 2013-03-14 16:30:18.954571413 +0100 @@ -3,27 +3,28 @@ 8:IO-APIC-edge rtc0 9:IO-APIC-fasteoi acpi 12:IO-APIC-edge i8042 - 16:IO-APIC-fasteoi uhci_hcd:usb6 - 17:IO-APIC-fasteoi uhci_hcd:usb7 - 18:IO-APIC-fasteoi ata_generic, uhci_hcd:usb8 - 19:IO-APIC-fasteoi ehci_hcd:usb2 - 20:IO-APIC-fasteoi uhci_hcd:usb3 - 21:IO-APIC-fasteoi uhci_hcd:usb4 - 22:IO-APIC-fasteoi uhci_hcd:usb5 - 23:IO-APIC-fasteoi ehci_hcd:usb1 + 16:IO-APIC-fasteoi uhci_hcd:usb4 + 17:IO-APIC-fasteoi uhci_hcd:usb5 + 18:IO-APIC-fasteoi ata_generic, uhci_hcd:usb6 + 19:IO-APIC-fasteoi ehci_hcd:usb8 + 20:IO-APIC-fasteoi uhci_hcd:usb1 + 21:IO-APIC-fasteoi uhci_hcd:usb2 + 22:IO-APIC-fasteoi uhci_hcd:usb3 + 23:IO-APIC-fasteoi ehci_hcd:usb7, i801_smbus 40:PCI-MSI-edge PCIe PME 41:PCI-MSI-edge PCIe PME 42:PCI-MSI-edge PCIe PME 43:PCI-MSI-edge ahci 44:PCI-MSI-edge i915 45:PCI-MSI-edge eth0 - 46:PCI-MSI-edge iwlagn + 46:PCI-MSI-edge iwlwifi 47:PCI-MSI-edge snd_hda_intel NMI:Non-maskable interrupts LOC:Local timer interrupts SPU:Spurious interrupts PMI:Performance monitoring interrupts IWI:IRQ work interrupts +RTR:APIC ICR read retries RES:Rescheduling interrupts CAL:Function call interrupts TLB:TLB shootdowns IRQ16 is routed differently (usb4 vs usb6), so that might be relevant. > Is occurrence of the "nobody cared" connected with any particular > device? Somebody reported a similar problem not long ago (although IIRC > it was for OHCI rather than UHCI) which appeared to be related to > activity on the built-in webcam. Will check this. No external devices are plugged in, I think the only internal one it has is bluetooth chip. I'll try turning it off. -- Jiri Kosina SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
