From mboxrd@z Thu Jan 1 00:00:00 1970 From: oiioeu at aol.com Date: Tue, 25 May 2010 04:24:01 -0400 (EDT) Subject: [ath9k-devel] oprofile the ath9k for low throughput rate and 3 questions In-Reply-To: 27840568 References: 27840568 Message-ID: <8CCC9FAC386BBA0-1674-1188@Webmail-d121.sysops.aol.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org I found: I got an average throughput about 6~7Mbps because I put the AP and STA very close(side by side), today I just put them 10 meters away from each other and I got an avg. throughput rate like 50Mbps, with latest OpenWrt r21560. I don't understant why put the AP and STA side by side would come out very low throughput, anyway. I did the oprofiling again by iperf for 3 times, and the log is attached. avg. 50Mbps of the throughput is still not alright, and I have another question that why the default_idle takes 30~40% of the CPU time? which means the CPU is idle for 30%~40% while the throughput rate is not as good as it could be? what would be the problem? I'm sorry to be very late, please please answer me, thank you! -----Original Message----- From: Luis R. Rodriguez To: Dave Taht Cc: ath9k-devel Sent: Thu, Apr 29, 2010 12:49 am Subject: Re: [ath9k-devel] oprofile the ath9k for low throughput rate and 3 questions On Wed, Apr 28, 2010 at 07:17:47AM -0700, Dave Taht wrote: > On 04/19/2010 07:05 PM, oiioeu at aol.com wrote: > > I got avg. 60Mbps of the throughput rate by iperf testing and had the testing environment like below: > > > OpenWrt: r18529 (I tried the latest r20851 and the throughput rate could be even worse ) > AP && STA h/w platform: IXP425 > wireless module: AR9280( 11na, HT40 ) > wireless driver: ath9k version matched OpenWrt r18529 > topology is like: PC1 - STA - AP - PC2 ( ethernet connection between PC1 and STA, AP and PC2, and the wireless > connection between STA and the AP. iperf client on PC1 and iperf server on PC2 ) > > then I added oprofile support to this throughput rate testing and had the throughput rate decrease to avg 8Mbps, here are my questions: > 1. whether the avg. 8Mbps of the throughput after adding the oprofile support seemed to be reasonable? > 2. why there were the warning messeges at the beginning of the opreport result and does it matter or not? > 3. anyone could point me is there anything abnormal from the opreport messeges that lead to the low throughput in my case? > the oprofile log are attached > > Interesting. I've been meaning to get around to oprofiling my hardware (nanostation M5) one of these days as I'd noted that I was achieving ~70Mbit via iperf and seeing (via top) that the hardware was spending 70% of its time in the "sirq" state. (whether or not that was the wireless or wired drivers doing that, I don't know). > > oprofile tends to be high overhead unless there is special on-chip counter support. > > As for this particular oprofile, I don't know, but it looks like ath9k_ioread32 is a good candidate for optimization, even without the huge oprofile slowdown.... ath9k_ioread32() could be made simpler by becoming a callback after we check for the serialization requirement. We can use a default callback (the current one) for pre-initialization and then then we can just peg the proper callback upon ath9k_hw_attach_ops(). The callback for the case where serialization is not required would be a straight forward read. This can be done for ath9k_iowrite32() as well. Luis _______________________________________________ ath9k-devel mailing list ath9k-devel at lists.ath9k.org https://lists.ath9k.org/mailman/listinfo/ath9k-devel -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20100525/561f1f00/attachment-0001.htm -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: oprofile.AP.log Url: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20100525/561f1f00/attachment-0002.txt -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: oprofile.SU.log Url: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20100525/561f1f00/attachment-0003.txt