Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:63088 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757306Ab0JLROV convert rfc822-to-8bit (ORCPT ); Tue, 12 Oct 2010 13:14:21 -0400 Received: by wyb28 with SMTP id 28so218715wyb.19 for ; Tue, 12 Oct 2010 10:14:20 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <201010121933.59209.br1@einfach.org> References: <201010121933.59209.br1@einfach.org> Date: Tue, 12 Oct 2010 12:14:19 -0500 Message-ID: Subject: Re: [ath5k-devel] How to profile this strange effect under high load? From: Qasim Javed To: Bruno Randolf Cc: linux-wireless , ath5k-devel@lists.ath5k.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: How about using trace-cmd and kernelshark with function graph tracer to see what is getting called so often? -Qasim On Tue, Oct 12, 2010 at 5:33 AM, Bruno Randolf wrote: > Hello! > > I am trying to debug a strange effect, I am seeing on soekris net48xx boards > with two ath5k interfaces: > > ?* wlan0 [phy0] configured in ad-hoc mode, A band, and it is getting a lot of > traffic routed thru it > ?* wlan1 [phy1] also configured in ad-hoc mode, G band, but not actively > sending (no IP address). > > I run iperf between two PCs attached by ethernet, UDP 25Mbps and I am sure all > traffic is routed thru wlan0 (phy0). The load on the SENDING box gets very > high: > > Mem: 27304K used, 99040K free, 0K shrd, 616K buff, 14128K cached > CPU: ? 0% usr ? 0% sys ? 0% nic ? 0% idle ? 0% io ? 5% irq ?93% sirq > Load average: 1.73 1.01 2.23 2/38 3128 > ?PID ?PPID USER ? ? STAT ? VSZ %MEM %CPU COMMAND > ?2772 ? ? 2 root ? ? RW ? ? ? 0 ? 0% ?71% [phy1] > ?2757 ? ? 2 root ? ? SW ? ? ? 0 ? 0% ?11% [phy0] > ?3128 ? 436 root ? ? R ? ? ?988 ? 1% ? 8% top > ? ?3 ? ? 2 root ? ? SW ? ? ? 0 ? 0% ? 5% [ksoftirqd/0] > ? ?5 ? ? 2 root ? ? SW ? ? ? 0 ? 0% ? 3% [events/0] > ? 56 ? ? 2 root ? ? SW ? ? ? 0 ? 0% ? 1% [bdi-default] > ?1383 ? ? 1 root ? ? S ? ? 1824 ? 1% ? 0% /usr/bin/oprofiled --session-dir=/r > > ...and the interesting thing is that [phy1] - the INACTIVE interface - > consumes much more CPU time than [phy0] which is actually transmitting. > > I have disabled ANI on wlan1, to avoid getting many MIB interrupts, but it > does not change much. > > I have dumped frames on phy1, and all it sees are a few beacon frames. > > I have tried wlan1 in managed mode - same effect. The effect is slightly less > in AP mode, though... > > I tried oprofile, but it shows mostly tx related things. > > So my question is: How can I find out, what [phy1] is so busy doing? Any ideas > how to profile this? > > Thanks in advance, > bruno > _______________________________________________ > ath5k-devel mailing list > ath5k-devel@lists.ath5k.org > https://lists.ath5k.org/mailman/listinfo/ath5k-devel >