Return-path: Received: from wf-out-1314.google.com ([209.85.200.175]:53617 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753368AbYIRVbF (ORCPT ); Thu, 18 Sep 2008 17:31:05 -0400 Received: by wf-out-1314.google.com with SMTP id 27so118981wfd.4 for ; Thu, 18 Sep 2008 14:31:04 -0700 (PDT) Message-ID: (sfid-20080918_233110_723350_60935E5E) Date: Thu, 18 Sep 2008 14:31:04 -0700 From: "Justin Mattock" To: "Luis R. Rodriguez" Subject: Re: [ath9k-devel] ath9k: massive unexplained latency in 2.6.27 (rc5, rc6, probably others) Cc: "Steven Noonan" , "Ingo Molnar" , "ath9k-devel@lists.ath9k.org" , linux-wireless , LKML In-Reply-To: <43e72e890809181344q416b5944w3332ee5a33db048c@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <43e72e890809181134ybbec8fdxcb2a466aa17fe390@mail.gmail.com> <43e72e890809181142n7738cd99g522e6688e68d11ce@mail.gmail.com> <43e72e890809181344q416b5944w3332ee5a33db048c@mail.gmail.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, Sep 18, 2008 at 1:44 PM, Luis R. Rodriguez wrote: > On Thu, Sep 18, 2008 at 12:00 PM, Steven Noonan wrote: >> On Thu, Sep 18, 2008 at 11:42 AM, Luis R. Rodriguez >> wrote: >>> On Thu, Sep 18, 2008 at 11:34 AM, Luis R. Rodriguez >>>> irqpoll is a monster of evil and that should make your system crawl to >>>> its knees. I would advise instead we work with you fixing the the >>>> missed interrupts issue upon rmmod. >>> >>> Also, please provide the output of >>> >>> cat /proc/interrupts >> >> Note that the problem necessitating use of irqpoll in the first place >> seems to only happen under certain conditions. I am unsure what these >> conditions are. Before 'ath9k: connectivity is lost after Group >> rekeying is done', > > You mean this patch: > > [PATCH] ath9k: connectivity is lost after Group rekeying is done > http://marc.info/?l=linux-wireless&m=122163541519736&w=2 > > So let me get this straight -- you applied this new patch, and haven't > tried disabling irqpoll now? > >> I had used rmmod/modprobe as my solution to the >> issue, which triggered the IRQ issue. > > Understood, but I also have used this before with ath9k and I got > exactly the same results you did -- I just refused to use it again and > just try to fix the issues present. > > ath9k issues tons of interrupts, not sure why irqpoll option would > cause latency so bad as the interrupts *are* handled. Not sure > *exactly* how irqpoll works but its description mentions using it > forces each interrupt handler on the IRQ line to check the interrupt > is for it. You have to keep in mind that not only are ath9k interrupts > then being sent to the devices on its line but it would seem that all > other devices on each line would suffer from the interrupts of the > other guys. Why ath9k would be the *only* culprit of causing latency > when using irqpoll if the irq line it son is clean? Beats me. > >> alcarin steven # cat /proc/interrupts >> CPU0 CPU1 >> 0x0: 63227 0 IO-APIC-edge hpet >> 0x8: 1 0 IO-APIC-edge rtc0 >> 0x9: 13080 0 IO-APIC-fasteoi acpi >> 0xe: 8195 0 IO-APIC-edge ide0 >> 0xf: 0 0 IO-APIC-edge ide1 >> 0x10: 36 0 IO-APIC-fasteoi uhci_hcd:usb5 >> 0x11: 10645 0 IO-APIC-fasteoi ath > > In this case your 11n Atheros device is on a clean line. > >> 0x12: 42 0 IO-APIC-fasteoi uhci_hcd:usb4 >> 0x17: 919 0 IO-APIC-fasteoi ehci_hcd:usb1, uhci_hcd:usb2 > > But it was this interrupt line which had an interrupt not handled. > > I'm not sure why this would happen. Can't we rule out ath9k then since > its on a different interrupt line? > >> 0x13: 32885 0 IO-APIC-fasteoi uhci_hcd:usb3, >> ata_piix, ohci1394 >> 0x200100: 1 0 PCI-MSI-edge eth0 >> 0x16: 223 0 IO-APIC-fasteoi HDA Intel >> NMI: 0 0 Non-maskable interrupts >> LOC: 78087 95718 Local timer interrupts >> RES: 11576 16384 Rescheduling interrupts >> CAL: 6862 8889 Function call interrupts >> TLB: 54 41 TLB shootdowns >> TRM: 0 0 Thermal event interrupts >> THR: 0 0 Threshold APIC interrupts >> SPU: 0 0 Spurious interrupts >> ERR: 0 > > Can you try to reproduce the irq not handled again? > >>> >>> and also please do not cross post to all these lists, just use >>> linux-wireless or ath9k. >>> >> >> Sorry, but in the past I've posted to linux-wireless, ath9k-devel, and >> all the maintainers of ath9k and didn't get a single response (except >> a 'me too' from a fellow ath9k user). I didn't just want to hear >> crickets this time. > > Patches speak more than words, but yeah sorry, we should have > addressed this there. I've personally have just been busy with > tackling aggregation. > > Luis > -- > 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/ > Appologize about that, I'm wondering what is or was the main commit that might be causing all of these disable irq #'s in usb, wireless, etc.. just doing a quick search one cant help but to think maybe this is something with tick.(but could be wrong); -- Justin P. Mattock