On Wed, Sep 08, 2010 at 11:05:48PM +0100, Chris Ball wrote: > Hi Anton, > > On Thu, Sep 09, 2010 at 01:57:50AM +0400, Anton Vorontsov wrote: > > Thanks! > > > > Would be also great if you could point out which patch causes > > most of the performance drop (if any)? > > > > Albert, if you could find time, can you also "bisect" the > > patchset? I wouldn't want to buy Nintendo WII just to debug the > > perf regression. ;-) FWIW, I tried to disable multiblock > > read/writes and test with SD cards, and still didn't notice > > any performance drops. > > > > Maybe it's SDIO IRQs that cause the performance drop for the > > WII case, as we delay them a little bit? Or it could be the > > patch that introduces threaded IRQ handler in whole causes > > it. If so, I guess we'd need to move some of the processing to > > the real IRQ context, keeping the handler lockless (if > > possible) or introducing a very fine grained locking. > > I didn't know anything about a reported performance drop, and I don't > think Andrew did either -- Albert's test results don't seem to have > made it to this list, or anywhere else that I can see. Could you > link to/repost his comments? > > (I'll be testing with libertas, so that will stress-test SDIO IRQs.) Sure thing, here are Albert's results. ----- Forwarded message from Albert Herranz <albert_herranz@xxxxxxxx> ----- Date: Mon, 02 Aug 2010 21:23:51 +0200 From: Albert Herranz <albert_herranz@xxxxxxxx> To: Anton Vorontsov <cbouatmailru@xxxxxxxxx> CC: akpm@xxxxxxxxxxxxxxxxxxxx, mm-commits@xxxxxxxxxxxxxxx, ben-linux@xxxxxxxxx, matt@xxxxxxxxxxxxxxxxx, pierre@xxxxxxxxx, w.sang@xxxxxxxxxxxxxx, mb@xxxxxxxxx Subject: Re: + sdhci-use-work-structs-instead-of-tasklets.patch added to -mm tree Hi, Some initial numbers regarding performance. The patchset seems to cause a noticeable performance drop. I've run two iperf client tests (see the two invocations of iperf -c) and two iperf server tests (see iperf -s invocation). == 2.6.33 == $ iperf -c 192.168.1.130 ------------------------------------------------------------ Client connecting to 192.168.1.130, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.1.127 port 40119 connected with 192.168.1.130 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.1 sec 1.05 MBytes 872 Kbits/sec $ iperf -c 192.168.1.130 ------------------------------------------------------------ Client connecting to 192.168.1.130, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.1.127 port 40120 connected with 192.168.1.130 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.0 sec 1.04 MBytes 870 Kbits/sec $ iperf -s ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 4] local 192.168.1.127 port 5001 connected with 192.168.1.130 port 36691 [ ID] Interval Transfer Bandwidth [ 4] 0.0-10.2 sec 3.61 MBytes 2.98 Mbits/sec [ 5] local 192.168.1.127 port 5001 connected with 192.168.1.130 port 36692 [ 5] 0.0-10.1 sec 4.94 MBytes 4.09 Mbits/sec == 2.6.33 + "sdhci: Move real work out of an atomic context" patchset == $ iperf -c 192.168.1.130 ------------------------------------------------------------ Client connecting to 192.168.1.130, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.1.127 port 39210 connected with 192.168.1.130 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.0 sec 368 KBytes 301 Kbits/sec $ iperf -c 192.168.1.130 ------------------------------------------------------------ Client connecting to 192.168.1.130, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.1.127 port 39211 connected with 192.168.1.130 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.2 sec 440 KBytes 354 Kbits/sec $ iperf -s ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 4] local 192.168.1.127 port 5001 connected with 192.168.1.130 port 57833 [ ID] Interval Transfer Bandwidth [ 4] 0.0-10.2 sec 2.37 MBytes 1.95 Mbits/sec [ 5] local 192.168.1.127 port 5001 connected with 192.168.1.130 port 57834 [ 5] 0.0-10.2 sec 2.30 MBytes 1.90 Mbits/sec The subjective feeling is too that the system is slower. Cheers, Albert ----- End forwarded message ----- -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
