Re: [lkp-developer] [sched/core] 6b94780e45: unixbench.score -4.5% regression
From: Ye Xiaolong
Date: Tue Jan 03 2017 - 02:13:31 EST
On 01/02, Vincent Guittot wrote:
>Hi Xiaolong,
>
>Le Monday 19 Dec 2016 à 08:14:53 (+0800), kernel test robot a écrit :
>>
>> Greeting,
>>
>> FYI, we noticed a -4.5% regression of unixbench.score due to commit:
>
>I have been able to restore performance on my platform with the patch below.
>Could you test it ?
>
>---
> kernel/sched/core.c | 1
> 1 file changed, 1 insertion(+)
>
>diff --git a/kernel/sched/core.c b/kernel/sched/core.c
>index 393759b..6e7d45c 100644
>--- a/kernel/sched/core.c
>+++ b/kernel/sched/core.c
>@@ -2578,6 +2578,7 @@ void wake_up_new_task(struct task_struct *p)
> __set_task_cpu(p, select_task_rq(p, task_cpu(p), SD_BALANCE_FORK, 0));
> #endif
> rq = __task_rq_lock(p, &rf);
>+ update_rq_clock(rq);
> post_init_entity_util_avg(&p->se);
>
> activate_task(rq, p, 0);
>--
>2.7.4
>
>Vincent
Hi, Vincent,
I applied your fix patch on top of 6b94780 ("sched/core: Use load_avg for selecting idlest group"),
and here is the comparison. (60df283834fd4def3c11ad2de3 is the fix commit id).
Seems the performance hasn't been restored back.
=========================================================================================
compiler/cpufreq_governor/kconfig/nr_task/rootfs/runtime/tbox_group/test/testcase:
gcc-6/performance/x86_64-rhel-7.2/100%/debian-x86_64-2016-08-31.cgz/300s/lkp-wsm-ep1/shell1/unixbench
commit:
f519a3f1c6b7a990e5aed37a8f853c6ecfdee945
6b94780e45c17b83e3e75f8aaca5a328db583c74
60df283834fd4def3c11ad2de3e6fc9e81b7dff1
f519a3f1c6b7a990 6b94780e45c17b83e3e75f8aac 60df283834fd4def3c11ad2de3
---------------- -------------------------- --------------------------
%stddev %change %stddev %change %stddev
\ | \ | \
25565 ± 0% -4.5% 24414 ± 0% -4.5% 24421 ± 0% unixbench.score
13223805 ± 2% -19.6% 10628072 ± 0% -21.3% 10412818 ± 1% unixbench.time.involuntary_context_switches
9.232e+08 ± 0% -4.3% 8.831e+08 ± 0% -4.3% 8.838e+08 ± 0% unixbench.time.minor_page_faults
1807 ± 0% -5.4% 1709 ± 0% -5.6% 1705 ± 0% unixbench.time.percent_of_cpu_this_job_got
5656 ± 0% -6.8% 5271 ± 0% -7.3% 5243 ± 0% unixbench.time.system_time
5743 ± 0% -4.0% 5514 ± 0% -3.9% 5516 ± 0% unixbench.time.user_time
29557557 ± 0% -2.6% 28781098 ± 0% -2.2% 28919280 ± 0% unixbench.time.voluntary_context_switches
741766 ± 2% -62.4% 279054 ± 1% -61.8% 283034 ± 1% interrupts.CAL:Function_call_interrupts
2912823 ± 0% -9.7% 2630010 ± 0% -8.7% 2660077 ± 0% softirqs.RCU
13223805 ± 2% -19.6% 10628072 ± 0% -21.3% 10412818 ± 1% time.involuntary_context_switches
126250 ± 0% -12.2% 110890 ± 0% -11.5% 111739 ± 0% vmstat.system.cs
31060 ± 1% -9.2% 28214 ± 0% -9.6% 28078 ± 0% vmstat.system.in
454.50 ±150% +164.7% 1203 ±166% +792.3% 4055 ± 18% numa-numastat.node0.numa_foreign
454.50 ±150% +164.7% 1203 ±166% +792.3% 4055 ± 18% numa-numastat.node0.numa_miss
4297 ± 15% -18.1% 3520 ± 57% -84.5% 666.40 ±113% numa-numastat.node1.numa_foreign
4297 ± 15% -18.1% 3520 ± 57% -84.5% 666.40 ±113% numa-numastat.node1.numa_miss
78.58 ± 0% -5.6% 74.20 ± 0% -6.0% 73.90 ± 0% turbostat.%Busy
2507 ± 0% -5.6% 2366 ± 0% -6.0% 2356 ± 0% turbostat.Avg_MHz
3.01 ± 2% +100.4% 6.03 ± 2% +100.1% 6.02 ± 0% turbostat.CPU%c3
2.35 ± 1% +6.8% 2.51 ± 4% +12.1% 2.64 ± 1% turbostat.CPU%c6
1.25 ± 5% -17.1% 1.04 ± 22% -32.3% 0.85 ± 5% perf-profile.children.cycles-pp.__irqentry_text_start
Thanks,
Xiaolong
>
>>
>>
>> commit: 6b94780e45c17b83e3e75f8aaca5a328db583c74 ("sched/core: Use load_avg for selecting idlest group")
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
>>
>> in testcase: unixbench
>> on test machine: 24 threads Nehalem-EP with 24G memory
>> with following parameters:
>>
>> runtime: 300s
>> nr_task: 100%
>> test: shell1
>> cpufreq_governor: performance
>>
>> test-description: UnixBench is the original BYTE UNIX benchmark suite aims to test performance of Unix-like system.
>> test-url: https://github.com/kdlucas/byte-unixbench
>>
>> In addition to that, the commit also has significant impact on the following tests:
>>
>> +------------------+-----------------------------------------------------------------------+
>> | testcase: change | unixbench: unixbench.score -2.9% regression |
>> | test machine | 8 threads Intel(R) Core(TM) i7 CPU 870 @ 2.93GHz with 6G memory |
>> | test parameters | nr_task=1 |
>> | | runtime=300s |
>> | | test=shell8 |
>> +------------------+-----------------------------------------------------------------------+
>>
>>
>> Details are as below:
>> -------------------------------------------------------------------------------------------------->
>>
>>
>> To reproduce:
>>
>> git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
>> cd lkp-tests
>> bin/lkp install job.yaml # job file is attached in this email
>> bin/lkp run job.yaml
>>
>> testcase/path_params/tbox_group/run: unixbench/300s-100%-shell1-performance/lkp-wsm-ep1
>>
>> f519a3f1c6b7a990 6b94780e45c17b83e3e75f8aac
>> ---------------- --------------------------
>> 25565 -5% 24414 unixbench.score
>> 29557557 28781098 unixbench.time.voluntary_context_switches
>> 5743 -4% 5514 unixbench.time.user_time
>> 9.232e+08 -4% 8.831e+08 unixbench.time.minor_page_faults
>> 1807 -5% 1709 unixbench.time.percent_of_cpu_this_job_got
>> 5656 -7% 5271 unixbench.time.system_time
>> 13223805 -20% 10628072 unixbench.time.involuntary_context_switches
>> 741766 -62% 279054 interrupts.CAL:Function_call_interrupts
>> 31060 -9% 28214 vmstat.system.in
>> 126250 -12% 110890 vmstat.system.cs
>> 78.58 -6% 74.20 turbostat.%Busy
>> 2507 -6% 2366 turbostat.Avg_MHz
>> 9134 ± 47% -6e+03 2973 ± 36% latency_stats.max.pipe_read.__vfs_read.vfs_read.SyS_read.entry_SYSCALL_64_fastpath
>> 380879 ± 10% 5e+05 887692 ± 49% latency_stats.sum.wait_on_page_bit_killable.__lock_page_or_retry.filemap_fault.__do_fault.handle_mm_fault.__do_page_fault.do_page_fault.page_fault
>> 31710 ± 15% -2e+04 10583 ± 14% latency_stats.sum.call_rwsem_down_write_failed.__vma_adjust.__split_vma.do_munmap.vm_munmap.elf_map.load_elf_binary.search_binary_handler.do_execveat_common.SyS_execve.do_syscall_64.return_from_SYSCALL_64
>> 51796 ± 4% -4e+04 15457 ± 10% latency_stats.sum.call_rwsem_down_write_failed.unlink_file_vma.free_pgtables.unmap_region.do_munmap.vm_munmap.elf_map.load_elf_binary.search_binary_handler.do_execveat_common.SyS_execve.do_syscall_64
>> 111998 ± 18% -7e+04 37074 ± 14% latency_stats.sum.call_rwsem_down_write_failed.__vma_adjust.__split_vma.do_munmap.mmap_region.do_mmap.vm_mmap_pgoff.SyS_mmap_pgoff.SyS_mmap.entry_SYSCALL_64_fastpath
>> 275087 ± 15% -2e+05 81973 ± 3% latency_stats.sum.call_rwsem_down_write_failed.unlink_file_vma.free_pgtables.unmap_region.do_munmap.mmap_region.do_mmap.vm_mmap_pgoff.SyS_mmap_pgoff.SyS_mmap.entry_SYSCALL_64_fastpath
>> 930993 ± 12% -6e+05 320520 ± 4% latency_stats.sum.call_rwsem_down_write_failed.vma_link.mmap_region.do_mmap.vm_mmap_pgoff.vm_mmap.elf_map.load_elf_binary.search_binary_handler.do_execveat_common.SyS_execve.do_syscall_64
>> 4755783 ± 9% -3e+06 1619348 ± 4% latency_stats.sum.call_rwsem_down_write_failed.__vma_adjust.__split_vma.split_vma.mprotect_fixup.do_mprotect_pkey.SyS_mprotect.entry_SYSCALL_64_fastpath
>> 5536067 ± 10% -4e+06 1929338 ± 3% latency_stats.sum.call_rwsem_down_write_failed.copy_process._do_fork.SyS_clone.do_syscall_64.return_from_SYSCALL_64
>> 9.032e+08 -4% 8.64e+08 perf-stat.page-faults
>> 9.032e+08 -4% 8.64e+08 perf-stat.minor-faults
>> 2.329e+09 2.269e+09 perf-stat.node-load-misses
>> 2.2e+09 -9% 2.011e+09 ± 5% perf-stat.dTLB-store-misses
>> 3.278e+10 -9% 2.987e+10 ± 6% perf-stat.dTLB-load-misses
>> 19484819 13% 21974129 perf-stat.cpu-migrations
>> 3.755e+13 -6% 3.54e+13 perf-stat.cpu-cycles
>> 3244 4% 3379 perf-stat.instructions-per-iTLB-miss
>> 4.536e+12 -4% 4.332e+12 perf-stat.branch-instructions
>> 2.303e+13 -4% 2.208e+13 perf-stat.instructions
>> 5.768e+12 -4% 5.517e+12 perf-stat.dTLB-loads
>> 3.567e+11 -4% 3.414e+11 perf-stat.cache-references
>> 2.97 2.93 perf-stat.branch-miss-rate%
>> 2.768e+10 2.699e+10 perf-stat.node-stores
>> 5.446e+10 -3% 5.275e+10 perf-stat.cache-misses
>> 0.03 -4% 0.03 perf-stat.iTLB-load-miss-rate%
>> 9.673e+09 -4% 9.294e+09 perf-stat.node-loads
>> 3.596e+12 -4% 3.442e+12 perf-stat.dTLB-stores
>> 0.61 0.62 perf-stat.ipc
>> 1.347e+11 -6% 1.27e+11 perf-stat.branch-misses
>> 7.098e+09 -8% 6.533e+09 perf-stat.iTLB-load-misses
>> 2.309e+13 -4% 2.206e+13 perf-stat.iTLB-loads
>> 79911173 -12% 70187035 perf-stat.context-switches
>>
>>
>>
>> turbostat._Busy
>>
>> 90 ++-------------------------------------*---*---------------------------+
>> | .. *...*.. |
>> 80 *+..*..*...*..*...*..*...*..*...O...* O O O O O...O..O...O O O
>> 70 O+ O O O O O O O O |
>> | |
>> 60 ++ |
>> 50 ++ |
>> | |
>> 40 ++ |
>> 30 ++ |
>> | |
>> 20 ++ |
>> 10 ++ |
>> | |
>> 0 ++----------------------------------O----------------------------------+
>>
>>
>>
>>
>>
>> unixbench.time.percent_of_cpu_this_job_got
>>
>> 2500 ++-------------------------------------------------------------------+
>> | |
>> | .*... |
>> 2000 ++ .*. *..*... |
>> *..*...*..*...*..*...*..*...*..O...*. O O O O O..O...O..O O O
>> O O O O O O O O O |
>> 1500 ++ |
>> | |
>> 1000 ++ |
>> | |
>> | |
>> 500 ++ |
>> | |
>> | |
>> 0 ++---------------------------------O---------------------------------+
>>
>>
>> vmstat.system.in
>>
>> 40000 ++------------------------------------------------------------------+
>> | .*...*.. |
>> 35000 ++ .*...*. |
>> 30000 *+.*...*..*...*..*..*...*..*...*..*. *..*...*..* |
>> O O O O O O O O O O O O O O O O O O O O
>> 25000 ++ |
>> | |
>> 20000 ++ |
>> | |
>> 15000 ++ |
>> 10000 ++ |
>> | |
>> 5000 ++ |
>> | |
>> 0 ++--------------------------------O---------------------------------+
>>
>> [*] bisect-good sample
>> [O] bisect-bad sample
>>
>>
>> Disclaimer:
>> Results have been estimated based on internal Intel analysis and are provided
>> for informational purposes only. Any difference in system hardware or software
>> design or configuration may affect actual performance.
>>
>>
>> Thanks,
>> Xiaolong
>