On Tue, Aug 18, 2020 at 9:32 PM Muni Sekhar <munisekharrms@gmail.com> wrote:
Hi all,
I’ve two identical Linux systems with only kernel differences. While doing kernel profiling with perf, I got the below mentioned metrics for Scheduler benchmarks.
1st system (older kernel version compared to the other system) benchmark result:
$ perf bench sched messaging -g 64 # Running 'sched/messaging' benchmark: # 20 sender and receiver processes per group # 64 groups == 2560 processes run
Total time: 2.936 [sec]
2nd system benchmark result:
$ perf bench sched messaging -g 64 # Running 'sched/messaging' benchmark: # 20 sender and receiver processes per group # 64 groups == 2560 processes run
Total time: 10.074 [sec]
So as per scheduler benchmark results, clearly a huge difference between two systems. Can anyone suggest to me how to dive deeper to know the root cause for it. Also are there any tunable kernel parameters related to this one?
-- Thanks, Sekhar
_______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Aside from very far different kernel version, I think you need to use perf record and visualized it with heat map too (check Brendan Gregg blog) On the lower level side, check cache miss on L1/L2/L3 rate on both configuration. That might reveal something -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaig...> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaig...> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>