Fengguang Wu <fengguang...@intel.com> writes: > On Tue, Oct 22, 2013 at 09:38:10PM -0700, Eric W. Biederman wrote: >> David Miller <da...@davemloft.net> writes: >> >> > From: fengguang...@intel.com >> > Date: Tue, 22 Oct 2013 22:41:29 +0100 >> > >> >> We noticed big netperf throughput regressions >> >> >> >> a4fe34bf902b8f709c63 2e685cad57906e19add7 >> >> ------------------------ ------------------------ >> >> 707.40 -40.7% 419.60 >> >> lkp-nex04/micro/netperf/120s-200%-TCP_STREAM >> >> 2775.60 -23.7% 2116.40 >> >> lkp-sb03/micro/netperf/120s-200%-TCP_STREAM >> >> 3483.00 -27.2% 2536.00 TOTAL >> >> netperf.Throughput_Mbps >> >> >> >> and bisected it to >> >> >> >> commit 2e685cad57906e19add7189b5ff49dfb6aaa21d3 >> >> Author: Eric W. Biederman <ebied...@xmission.com> >> >> Date: Sat Oct 19 16:26:19 2013 -0700 >> >> >> >> tcp_memcontrol: Kill struct tcp_memcontrol >> > >> > Eric please look into this, I'd rather have a fix to apply than revert your >> > work. >> >> Will do I expect some ordering changed, and that changed the cache line >> behavior. >> >> If I can't find anything we can revert this one particular patch without >> affecting anything else, but it would be nice to keep the data structure >> smaller. >> >> Fengguag what would I need to do to reproduce this? > > Eric, attached is the kernel config. > > We used these commands in the test: > > netserver > netperf -t TCP_STREAM -c -C -l 120 # repeat 64 times and get > average > > btw, we've got more complete change set (attached) and also noticed > performance increase in the TCP_SENDFILE case: > > a4fe34bf902b8f709c63 2e685cad57906e19add7 > ------------------------ ------------------------ > 707.40 -40.7% 419.60 > lkp-nex04/micro/netperf/120s-200%-TCP_STREAM > 2572.20 -17.7% 2116.20 > lkp-sb03/micro/netperf/120s-200%-TCP_MAERTS > 2775.60 -23.7% 2116.40 > lkp-sb03/micro/netperf/120s-200%-TCP_STREAM > 1006.60 -54.4% 459.40 > lkp-sbx04/micro/netperf/120s-200%-TCP_STREAM > 3278.60 -25.2% 2453.80 > lkp-t410/micro/netperf/120s-200%-TCP_MAERTS > 1902.80 +21.7% 2315.00 > lkp-t410/micro/netperf/120s-200%-TCP_SENDFILE > 3345.40 -26.7% 2451.00 > lkp-t410/micro/netperf/120s-200%-TCP_STREAM > 15588.60 -20.9% 12331.40 TOTAL > netperf.Throughput_Mbps
I have a second question. Do you mount the cgroup filesystem? Do you set memory.kmem.tcp.limit_in_bytes? If you aren't setting any memory cgroup limits or creating any groups this change should not have had any effect whatsoever. And you haven't mentioned it so I don't expect you are enabling the memory cgroup limits explicitly. If you have enabled the memory cgroups can you please describe your configuration as that may play a significant role. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
