TCP stream performance regression due to c377411f2494a931ff7facdbb3a6839b1266bcf6
in [Kernel]
|
Prev: TCP stream performance regression due to c377411f2494a931ff7facdbb3a6839b1266bcf6
Next: Sound goes too fast due to commit 7b3a177b0
From: Alex,Shi on 18 Jun 2010 04:30 In our netperf testing, TCP_STREAM56 shows about 20% or more performance regression on WSM/NHM and tigerton machines. The testing boot up both netserver and client on localhost. The testing command like this: ../snapshot_script_net TC_STREAM56 127.0.0.1 We found the following commit causes this issue. c377411f2494a931ff7facdbb3a6839b1266bcf6 Revert this commit will recover this regression on all machine. Regards! Alex -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Eric Dumazet on 24 Jun 2010 13:20
Le vendredi 18 juin 2010 à 16:26 +0800, Zhang, Yanmin a écrit : > More info about the testing: > It's a loopback testing. We start one client netperf process to communicate with netserver process in a stream TCP testing. To reduce the cpu cache effect, we bind the 2 processes on 2 different physical cpus. > #taskset -c 0 ./netserver > #taskset -c 15 ./netperf -t TCP_STREAM -l 60 -H 127.0.0.1 -i 50,3 -I 99,5 -- -s 57344 -S 57344 -m 4096 > Thanks guys We corrected a proven vulnerability in network stack. If you want better netperf results, just increase size of your sockets buffers. 57344 is _very_ low for localhost communication, given lo MTU is 16436. As we also increased skb->truesize lately, you might also increase buffer size regardless of this (net: sk_add_backlog() take rmem_alloc into account) commit. In my case, I saw following improvement : Under huge stress from a multiqueue/RPS enabled NIC, a single flow udp receiver can now process ~200.000 pps (instead of ~100 pps before the patch) on a 8 core machine. Thats a 200.000 % increase, in a situation no tuning was possible ;) > >>-----Original Message----- > >>From: Shi, Alex > >>Sent: 2010年6月18日 15:17 > >>To: eric.dumazet(a)gmail.com; davem(a)davemloft.net > >>Cc: Chen, Tim C; Zhang, Yanmin; linux-kernel(a)vger.kernel.org > >>Subject: TCP stream performance regression due to > >>c377411f2494a931ff7facdbb3a6839b1266bcf6 > >> > >>In our netperf testing, TCP_STREAM56 shows about 20% or more performance > >>regression on WSM/NHM and tigerton machines. The testing boot up both > >>netserver and client on localhost. The testing command like this: > >>./snapshot_script_net TC_STREAM56 127.0.0.1 > >> > >>We found the following commit causes this issue. > >>c377411f2494a931ff7facdbb3a6839b1266bcf6 > >>Revert this commit will recover this regression on all machine. > >> > >>Regards! > >>Alex > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |