Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758151AbXFPWvX (ORCPT ); Sat, 16 Jun 2007 18:51:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757287AbXFPWvA (ORCPT ); Sat, 16 Jun 2007 18:51:00 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:46754 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753924AbXFPWu6 (ORCPT ); Sat, 16 Jun 2007 18:50:58 -0400 Date: Sat, 16 Jun 2007 15:49:46 -0700 From: Stephen Hemminger To: Maximilian Engelhardt Cc: netdev , "linux-kernel" , "linux-wireless" , Michael Buesch , Gary Zambrano , "Jeff Garzik" , "Arnaldo Carvalho de Melo" Subject: Re: b44: high ping times with wireless-dev Message-ID: <20070616154946.5fb6b013@localhost.localdomain> In-Reply-To: <200706162327.47413.maxi@daemonizer.de> References: <200706162327.47413.maxi@daemonizer.de> Organization: Linux Foundation X-Mailer: Claws Mail 2.9.2 (GTK+ 2.10.12; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4084 Lines: 98 On Sat, 16 Jun 2007 23:27:43 +0200 Maximilian Engelhardt 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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/