Re: [tip:timers/core] [timers] 7ee9887703: netperf.Throughput_Mbps -1.2% regression

[Frederic Weisbecker]

Le Fri, Mar 01, 2024 at 04:09:24PM +0800, kernel test robot a écrit :
> 
> 
> Hello,
> 
> kernel test robot noticed a -1.2% regression of netperf.Throughput_Mbps on:
> 
> 
> commit: 7ee988770326fca440472200c3eb58935fe712f6 ("timers: Implement the hierarchical pull model")
> https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git timers/core
> 
> testcase: netperf
> test machine: 128 threads 2 sockets Intel(R) Xeon(R) Gold 6338 CPU @ 2.00GHz (Ice Lake) with 256G memory
> parameters:
> 
> 	ip: ipv4
> 	runtime: 300s
> 	nr_threads: 200%
> 	cluster: cs-localhost
> 	test: SCTP_STREAM
> 	cpufreq_governor: performance
> 
> 
> 
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-lkp/202403011511.24defbbd-oliver.sang@xxxxxxxxx
> 
> 
> Details are as below:
> -------------------------------------------------------------------------------------------------->
> 
> 
> The kernel config and materials to reproduce are available at:
> https://download.01.org/0day-ci/archive/20240301/202403011511.24defbbd-oliver.sang@xxxxxxxxx
> 
> =========================================================================================
> cluster/compiler/cpufreq_governor/ip/kconfig/nr_threads/rootfs/runtime/tbox_group/test/testcase:
>   cs-localhost/gcc-12/performance/ipv4/x86_64-rhel-8.3/200%/debian-12-x86_64-20240206.cgz/300s/lkp-icl-2sp2/SCTP_STREAM/netperf
> 
> commit: 
>   57e95a5c41 ("timers: Introduce function to check timer base is_idle flag")
>   7ee9887703 ("timers: Implement the hierarchical pull model")

Is this something that is observed also with the commits that follow in this
branch?

Ie: would it be possible to compare instead:

    57e95a5c4117 (timers: Introduce function to check timer base is_idle flag)
VS
    b2cf7507e186 (timers: Always queue timers on the local CPU)

Because the improvements introduced by 7ee9887703 are mostly relevant after
b2cf7507e186.

Thanks.