Re: [PATCH] rhashtable: use per-init-site lockdep classes for bucket locks

[kernel test robot <yi1.lai@intel.com>]

Hello,

kernel test robot noticed a 12.5% regression of stress-ng.shm-sysv.ops_per_sec on:


commit: 62d8460a4e7a3ee028e5134d86169001490e7a60 ("[PATCH] rhashtable: use per-init-site lockdep classes for bucket locks")
url: https://github.com/intel-lab-lkp/linux/commits/quanyeyang-via-B4-Relay/rhashtable-use-per-init-site-lockdep-classes-for-bucket-locks/20260815-014140
patch link: https://lore.kernel.org/all/20260801-fix-rhashtable-bucket-lockdep-v1-1-15a0f8ae094c@gmail.com/
patch subject: [PATCH] rhashtable: use per-init-site lockdep classes for bucket locks

testcase: stress-ng
config: x86_64-rhel-9.4
compiler: gcc-14
test machine: 224 threads 2 sockets Intel(R) Xeon(R) Platinum 8480CTDX (Sapphire Rapids) with 256G memory
parameters:

	nr_threads: 100%
	testtime: 60s
	test: shm-sysv
	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 <yi1.lai@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202608280842.861e5949-lkp@intel.com


Details are as below:
-------------------------------------------------------------------------------------------------->


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260828/202608280842.861e5949-lkp@intel.com

=========================================================================================
compiler/cpufreq_governor/kconfig/nr_threads/rootfs/tbox_group/test/testcase/testtime:
  gcc-14/performance/x86_64-rhel-9.4/100%/debian-13-x86_64-20250902.cgz/lkp-spr-r02/shm-sysv/stress-ng/60s

commit: 
  0131b508c0 ("Merge tag 'ntfs-for-7.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/ntfs")
  62d8460a4e ("[PATCH] rhashtable: use per-init-site lockdep classes for bucket locks")

0131b508c0e2489e 62d8460a4e7a3ee028e5134d861
---------------- --------------------------- 
    192413           +44.1%     277255        stress-ng.shm-sysv.nanosecs_per_shmat_call
    349549           +24.2%     433996        stress-ng.shm-sysv.nanosecs_per_shmdt_call
    174600           +51.9%     265191        stress-ng.shm-sysv.nanosecs_per_shmget_call
    793610           -12.5%     694260        stress-ng.shm-sysv.ops
     13236           -12.5%      11578        stress-ng.shm-sysv.ops_per_sec
     65737           -10.0%      59167 ±  4%  stress-ng.time.involuntary_context_switches
  53645785           -12.0%   47213499 ±  2%  stress-ng.time.minor_page_faults
      4660           +24.6%       5806        stress-ng.time.percent_of_cpu_this_job_got
      2585           +27.8%       3305        stress-ng.time.system_time
    214.61           -14.7%     183.11        stress-ng.time.user_time
  10735595            -7.0%    9986470        stress-ng.time.voluntary_context_switches
 

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.


-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki