On Wed, Oct 23, 2013 at 02:43:14AM -0700, Eric W. Biederman wrote: > 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
Sorry it's not about repeating, but running 64 netperf in parallel. The number 64 is 2 times the number of logical CPUs. > > 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? No I didn't mount cgroup at all. > 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/
