Hi, Mel,

On Wed, 2022-04-20 at 14:24 +0800, ying.huang@intel.com wrote:
> Hi, Mel,
> 
> On Mon, 2022-04-18 at 22:18 +0800, kernel test robot wrote:
> > (please be noted we reported "[sched/fair]  2cfb7a1b03:  fsmark.files_per_sec
> > -26.2% regression" at
> > https://lore.kernel.org/all/20220303153108.GC14527@xsang-OptiPlex-9020/
> > when this is still on branch:
> > commit: 2cfb7a1b031b0e816af7a6ee0c6ab83b0acdf05a ("sched/fair: Improve consistency of allowed NUMA balance calculations")
> > https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git sched/core
> > 
> > now we noticed the similar performance changes as well as some others are
> > still existing on mainline, so report this again for information)
> > 
> > 
> > Greeting,
> > 
> > FYI, we noticed a -19.8% regression of stress-ng.fstat.ops_per_sec due to commit:
> > 
> > 
> > commit: 2cfb7a1b031b0e816af7a6ee0c6ab83b0acdf05a ("sched/fair: Improve consistency of allowed NUMA balance calculations")
> > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> > 
> > in testcase: stress-ng
> > on test machine: 96 threads 2 sockets Ice Lake with 256G memory
> > with following parameters:
> > 
> > 	nr_threads: 10%
> > 	disk: 1HDD
> > 	testtime: 60s
> > 	fs: f2fs
> > 	class: filesystem
> > 	test: fstat
> > 	cpufreq_governor: performance
> > 	ucode: 0xb000280
> > 
> > 
> > In addition to that, the commit also has significant impact on the following tests:
> > 
> > +------------------+-------------------------------------------------------------------------------------+
> > > testcase: change | phoronix-test-suite: phoronix-test-suite.neatbench.CPU.fps 12.5% improvement        |
> > > test machine     | 96 threads 2 sockets Intel(R) Xeon(R) Gold 6252 CPU @ 2.10GHz with 512G memory      |
> > > test parameters  | cpufreq_governor=performance                                                        |
> > >                  | option_a=CPU                                                                        |
> > >                  | test=neatbench-1.0.4                                                                |
> > >                  | ucode=0x500320a                                                                     |
> > +------------------+-------------------------------------------------------------------------------------+
> > > testcase: change | phoronix-test-suite: phoronix-test-suite.neatbench.All.fps 15.2% improvement        |
> > > test machine     | 96 threads 2 sockets Intel(R) Xeon(R) Gold 6252 CPU @ 2.10GHz with 512G memory      |
> > > test parameters  | cpufreq_governor=performance                                                        |
> > >                  | option_a=All (CPU + GPU)                                                            |
> > >                  | test=neatbench-1.0.4                                                                |
> > >                  | ucode=0x500320a                                                                     |
> > +------------------+-------------------------------------------------------------------------------------+
> > > testcase: change | fsmark: fsmark.files_per_sec -9.9% regression                                       |
> > > test machine     | 192 threads 4 sockets Intel(R) Xeon(R) Platinum 9242 CPU @ 2.30GHz with 192G memory |
> > > test parameters  | cpufreq_governor=performance                                                        |
> > >                  | disk=1BRD_48G                                                                       |
> > >                  | filesize=4M                                                                         |
> > >                  | fs=f2fs                                                                             |
> > >                  | iterations=1x                                                                       |
> > >                  | nr_threads=64t                                                                      |
> > >                  | sync_method=fsyncBeforeClose                                                        |
> > >                  | test_size=24G                                                                       |
> > >                  | ucode=0x500320a                                                                     |
> > +------------------+-------------------------------------------------------------------------------------+
> > > testcase: change | fsmark: fsmark.files_per_sec -26.2% regression                                      |
> > > test machine     | 192 threads 4 sockets Intel(R) Xeon(R) Platinum 9242 CPU @ 2.30GHz with 192G memory |
> > > test parameters  | cpufreq_governor=performance                                                        |
> > >                  | disk=1BRD_48G                                                                       |
> > >                  | filesize=4M                                                                         |
> > >                  | fs=ext4                                                                             |
> > >                  | iterations=1x                                                                       |
> > >                  | nr_threads=64t                                                                      |
> > >                  | sync_method=NoSync                                                                  |
> > >                  | test_size=24G                                                                       |
> > >                  | ucode=0x500320a                                                                     |
> > +------------------+-------------------------------------------------------------------------------------+
> > > testcase: change | stress-ng: stress-ng.fstat.ops_per_sec -20.1% regression                            |
> > > test machine     | 96 threads 2 sockets Ice Lake with 256G memory                                      |
> > > test parameters  | class=filesystem                                                                    |
> > >                  | cpufreq_governor=performance                                                        |
> > >                  | disk=1HDD                                                                           |
> > >                  | fs=xfs                                                                              |
> > >                  | nr_threads=10%                                                                      |
> > >                  | test=fstat                                                                          |
> > >                  | testtime=60s                                                                        |
> > >                  | ucode=0xb000280                                                                     |
> > +------------------+-------------------------------------------------------------------------------------+
> > > testcase: change | fsmark: fsmark.files_per_sec -16.3% regression                                      |
> > > test machine     | 192 threads 4 sockets Intel(R) Xeon(R) Platinum 9242 CPU @ 2.30GHz with 192G memory |
> > > test parameters  | cpufreq_governor=performance                                                        |
> > >                  | disk=1BRD_48G                                                                       |
> > >                  | filesize=4M                                                                         |
> > >                  | fs=ext4                                                                             |
> > >                  | iterations=1x                                                                       |
> > >                  | nr_threads=64t                                                                      |
> > >                  | sync_method=fsyncBeforeClose                                                        |
> > >                  | test_size=24G                                                                       |
> > >                  | ucode=0x500320a                                                                     |
> > +------------------+-------------------------------------------------------------------------------------+
> > > testcase: change | stress-ng: stress-ng.fstat.ops_per_sec -20.2% regression                            |
> > > test machine     | 96 threads 2 sockets Ice Lake with 256G memory                                      |
> > > test parameters  | class=filesystem                                                                    |
> > >                  | cpufreq_governor=performance                                                        |
> > >                  | disk=1HDD                                                                           |
> > >                  | fs=xfs                                                                              |
> > >                  | nr_threads=10%                                                                      |
> > >                  | test=fstat                                                                          |
> > >                  | testtime=60s                                                                        |
> > >                  | ucode=0xb000280                                                                     |
> > +------------------+-------------------------------------------------------------------------------------+
> > 
> 
> When I worked on the following regression report,
> 
> https://lore.kernel.org/lkml/87tuc7fp9k.fsf@yhuang6-desk2.ccr.corp.intel.com/
> 
> I found stress-ng throughput will regress if the tasks are distrubuted
> more evenly among NUMA nodes.  So for this regression, I re-tested with
> mpstat per node statistics.  The results are as follows,
> 
> 	mpstat.node.0.user%	mpstat.node.1.user%	mpstat.node.0.sys%	mpstat.node.1.sys%
> 889c5d60fb	       3.04		       2.65		      30.0		      25.8
> 2cfb7a1b03	       2.39		       2.28		      31.2		      28.9
> 
> It can be found that the task are balanced better with the commit
> 2cfb7a1b03.  So I think the regression isn't a real problem.

I think stress-ng isn't a good workload to evaluate the effect of this
patch.  Can you teach me which workloads are appropriate?

Best Regards,
Huang, Ying