Messages in this thread | | | Date | Wed, 17 Aug 2016 14:14:05 +0800 | From | Aaron Lu <> | Subject | Re: [LKP] [lkp] [sctp] a6c2f79287: netperf.Throughput_Mbps -37.2% regression |
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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 ] }
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