I'll include this fix in the next patch that incorporates any other review comments coming my way.. Thanks for pointing it out.
-Koushik > -----Original Message----- > From: Arthur Kepner [mailto:[EMAIL PROTECTED] > Sent: Friday, July 08, 2005 8:31 AM > To: Raghavendra Koushik > Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]; > netdev@vger.kernel.org; [EMAIL PROTECTED]; > [EMAIL PROTECTED]; [EMAIL PROTECTED] > Subject: RE: [PATCH 2.6.12.1 5/12] S2io: Performance improvements > > On Thu, 7 Jul 2005, Raghavendra Koushik wrote: > > > .... > > On an Altix machine I believe the readq was necessary to flush > > the PIO writes. How long did you run the tests? I had seen > > in long duration tests that an occasional write > > (TXDL control word and the address) would be missed and the xmit > > Get's stuck. > > > > The most recent tests I did used pktgen, and they ran for a total > time of ~.5 hours (changing pkt_size every 30 seconds or so). The > pktgen tests and other tests (like nttcp) have been run > several times, > so I've exercised the card for a total of several hours without > any problems. > > > > > > > > > FWIW, I've done quite a few performance measurements with > the patch > > > I posted earlier, and it's worked well. For 1500 byte > mtus throughput > > > goes up by ~20%. Is even the mmiowb() unnecessary? > > > > > > > Was this on 2.4 kernel because I think the readq would not have a > > significant impact on 2.6 kernels due to TSO. > > (with TSO on the number of packets that actually enter the > > Xmit routine would be reduced apprx 40 times). > > ..... > > This was with a 2.6 kernel (with TSO on). PIO reads are pretty > expensive on Altix, so eliminating them really helps us. > > For big mtus (>=4KBytes) the benefit of replacing the readq() > with mmiowb() in s2io_xmit() is negligible. > > -- > Arthur > - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
