On Sat, 16 Jun 2007 23:27:43 +0200 Maximilian Engelhardt <maxi@xxxxxxxxxxxxx> wrote: > Hello, > > I recently did some test and found out something interesting about the b44 > problem I wrote earlier. > > The problem is the following: > When I use my BCM4401 with the b44 driver in wireless-dev I get very high ping > times looking like this: > > 64 bytes from 172.30.10.1: icmp_seq=1 ttl=64 time=1863 ms > 64 bytes from 172.30.10.1: icmp_seq=2 ttl=64 time=855 ms > 64 bytes from 172.30.10.1: icmp_seq=3 ttl=64 time=1855 ms > 64 bytes from 172.30.10.1: icmp_seq=4 ttl=64 time=855 ms > 64 bytes from 172.30.10.1: icmp_seq=5 ttl=64 time=1854 ms > 64 bytes from 172.30.10.1: icmp_seq=6 ttl=64 time=854 ms > 64 bytes from 172.30.10.1: icmp_seq=7 ttl=64 time=1851 ms > 64 bytes from 172.30.10.1: icmp_seq=8 ttl=64 time=851 ms > 64 bytes from 172.30.10.1: icmp_seq=9 ttl=64 time=1851 ms > 64 bytes from 172.30.10.1: icmp_seq=10 ttl=64 time=851 ms > > I also found out that shortly after I boot my laptop and log into kde ping > times are not that high but start to increase very quickly: > > 64 bytes from 172.30.10.1: icmp_seq=53 ttl=64 time=2.19 ms > 64 bytes from 172.30.10.1: icmp_seq=54 ttl=64 time=2.22 ms > 64 bytes from 172.30.10.1: icmp_seq=55 ttl=64 time=2.20 ms > 64 bytes from 172.30.10.1: icmp_seq=56 ttl=64 time=2.20 ms > 64 bytes from 172.30.10.1: icmp_seq=57 ttl=64 time=18.6 ms > 64 bytes from 172.30.10.1: icmp_seq=58 ttl=64 time=1268 ms > 64 bytes from 172.30.10.1: icmp_seq=59 ttl=64 time=268 ms > 64 bytes from 172.30.10.1: icmp_seq=60 ttl=64 time=1268 ms > 64 bytes from 172.30.10.1: icmp_seq=61 ttl=64 time=268 ms > 64 bytes from 172.30.10.1: icmp_seq=62 ttl=64 time=6.08 ms > 64 bytes from 172.30.10.1: icmp_seq=63 ttl=64 time=268 ms > 64 bytes from 172.30.10.1: icmp_seq=64 ttl=64 time=1264 ms > 64 bytes from 172.30.10.1: icmp_seq=65 ttl=64 time=264 ms > > After some time digging around I found out something really interesting. When > I play some music ping times are immediately lower. If I stop playing music > they are back to the same times as they were before. > > I guess that there is a problem with interrupts so I post some information of > my system in hope it will be usefull. > > maxi@koala:~$ cat /proc/interrupts > CPU0 > 0: 126317 XT-PIC-XT timer > 1: 3600 XT-PIC-XT i8042 > 2: 0 XT-PIC-XT cascade > 7: 1 XT-PIC-XT parport0 > 8: 1 XT-PIC-XT rtc > 9: 17371 XT-PIC-XT acpi > 10: 13237 XT-PIC-XT firewire_ohci, yenta, yenta, ehci_hcd:usb1, > uhci_hcd:usb3, uhci_hcd:usb4, Intel 82801DB-ICH4, Intel 82801DB-ICH4 Modem, > eth0 > 11: 89059 XT-PIC-XT uhci_hcd:usb2, i915@pci:0000:00:02.0 > 12: 632 XT-PIC-XT i8042 > 14: 10354 XT-PIC-XT libata > 15: 7408 XT-PIC-XT libata > NMI: 0 > ERR: 0 > > > [...] > ACPI: PCI Interrupt Link [LNKD] enabled at IRQ 10 > ACPI: PCI Interrupt 0000:02:02.0[A] -> Link [LNKD] -> GSI 10 (level, low) -> > IRQ 10 > ssb: Sonics Silicon Backplane found on PCI device 0000:02:02.0 > b44.c:v2.0 > eth0: Broadcom 44xx/47xx 10/100BaseT Ethernet 00:c0:9f:29:99:a7 > [...] > > This problem did only happen with wireless-dev (checkout this evening) and > with -mm kernels I used some time ago for testing. Currently I'm running > 2.6.22-rc4 that works perfectly fine and doesn't show that problem. > > Maxi Can you build with APIC for uniprocessor. There is lots of IRQ sharing, so - one of the other device's may be not handling shared IRQ properly. Try unloading firewhire modem and yenta devices. - IRQ might be set edge triggered which doesn't work with NAPI or shared IRQ. -- Stephen Hemminger <shemminger@xxxxxxxxxxxxxxxxxxxx> - To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
