On Wed, Aug 17, 2016 at 02:14:05PM +0800, Aaron Lu wrote: > On Wed, Aug 17, 2016 at 01:41:04PM +0800, Xin Long wrote: > > > The perf-profile data for the two commits are attached(for the case of > > > prsctp_enable=1, the perf-profile data doesn't get collected for the 0 > > > case for some reason, I'm checking the problem now). > > > > > > The CPU gets much more idle time in the bisected commit a6c2f79287: > > > > > > 68.89% 0.70% [kernel.kallsyms] [k] entry_SYSCALL_64_fastpath > > > 49.32% 0.12% [kernel.kallsyms] [k] sys_sendmsg > > > 49.17% 0.12% [kernel.kallsyms] [k] __sys_sendmsg > > > 48.58% 0.22% [kernel.kallsyms] [k] ___sys_sendmsg > > > 46.69% 0.06% [kernel.kallsyms] [k] sock_sendmsg > > > 46.31% 0.16% [kernel.kallsyms] [k] inet_sendmsg > > > 45.90% 0.98% [kernel.kallsyms] [k] sctp_sendmsg > > > 29.66% 0.45% [kernel.kallsyms] [k] sctp_do_sm > > > 29.54% 0.23% [kernel.kallsyms] [k] cpu_startup_entry > > > 28.81% 0.68% [kernel.kallsyms] [k] sctp_cmd_interpreter.isra.24 > > > 26.20% 0.00% [kernel.kallsyms] [k] start_secondary > > > 23.04% 0.09% [kernel.kallsyms] [k] sctp_inq_push > > > 23.03% 0.08% [kernel.kallsyms] [k] call_cpuidle > > > 22.94% 0.00% [kernel.kallsyms] [k] cpuidle_enter > > > 22.60% 0.18% [kernel.kallsyms] [k] cpuidle_enter_state > > > 21.99% 21.99% [kernel.kallsyms] [k] intel_idle > > > ... ... > > > > > > While its immediate parent commit 826d253d57 is mostly busy working: > > > > > > 98.53% 0.83% [kernel.kallsyms] [k] entry_SYSCALL_64_fastpath > > > 78.13% 0.12% [kernel.kallsyms] [k] sys_sendmsg > > > 78.03% 0.16% [kernel.kallsyms] [k] __sys_sendmsg > > > 77.08% 0.28% [kernel.kallsyms] [k] ___sys_sendmsg > > > 74.44% 0.08% [kernel.kallsyms] [k] sock_sendmsg > > > 73.82% 0.13% [kernel.kallsyms] [k] inet_sendmsg > > > 73.34% 1.44% [kernel.kallsyms] [k] sctp_sendmsg > > > 47.52% 0.75% [kernel.kallsyms] [k] sctp_do_sm > > > 46.19% 0.90% [kernel.kallsyms] [k] sctp_cmd_interpreter.isra.24 > > > 37.17% 1.43% [kernel.kallsyms] [k] sctp_outq_flush > > > 36.93% 0.08% [kernel.kallsyms] [k] sctp_outq_uncork > > > 34.24% 0.15% [kernel.kallsyms] [k] sctp_inq_push > > > ... ... > > > No idle related function above 1%. > > > > > > Will the bisected commit make the idle possible? > > No, not at all. :) > > > > pls help to debug as I said in the last reply. > > OK, will see how to do that. > > In the meantime, I just tried to reproduce on my own desktop: > Sandybridge i7-2600 CPU @ 3.40GHz and it reproduced: > $ cat 4.7.0-rc6-01198-ga6c2f792873a/0/netperf.json > { > "netperf.Throughput_Mbps": [ > 752.9450000000002 > ] > } > $ cat 4.7.0-rc6-01197-g826d253d57b1/0/netperf.json > { > "netperf.Throughput_Mbps": [ > 1068.5556249999997 > ] > } On top of commit 826d253d57b1 ("sctp: add SCTP_PR_ASSOC_STATUS on sctp sockopt") I applied the below commit: >From 98dd2532b14e29dcc2ab40a7348755531afa79e4 Mon Sep 17 00:00:00 2001 From: Aaron Lu Date: Wed, 17 Aug 2016 14:20:00 +0800 Subject: [PATCH] sctp: test --- include/net/sctp/structs.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index d8e464aacb20..932f2780d3a4 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -602,6 +602,9 @@ struct sctp_chunk { /* This needs to be recoverable for SCTP_SEND_FAILED events. */ struct sctp_sndrcvinfo sinfo; + unsigned long prsctp_param; + int sent_count; + /* Which association does this belong to? */ struct sctp_association *asoc; -- 2.5.5 Then the performance dropped to the same as the bisected commit a6c2f792873a: $ cat 4.7.0-rc6-01198-g98dd2532b14e/0/netperf.json { "netperf.Throughput_Mbps": [ 754.494375 ] } I think this agrees with the perf data in that the newly added function doesn't show up in the perf-profile but still, the performance drops. So the only possible reason is the newly added fields to the sctp_chunk structure. Is this expected? Thanks, Aaron