[linus:master] [x86/stackprotector] f3856cd343: will-it-scale.per_thread_ops 1.9% regression

[kernel test robot]

Hello,

kernel test robot noticed a 1.9% regression of will-it-scale.per_thread_ops on:


commit: f3856cd343b6371530c9af3c97354cdc003f3203 ("x86/stackprotector: Move __stack_chk_guard to percpu hot section")
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master


testcase: will-it-scale
config: x86_64-rhel-9.4
compiler: gcc-12
test machine: 384 threads 2 sockets Intel(R) Xeon(R) 6972P (Granite Rapids) with 128G memory
parameters:

	nr_task: 100%
	mode: thread
	test: futex4
	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/202504081055.4c396e03-lkp@xxxxxxxxx


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


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20250408/202504081055.4c396e03-lkp@xxxxxxxxx

=========================================================================================
compiler/cpufreq_governor/kconfig/mode/nr_task/rootfs/tbox_group/test/testcase:
  gcc-12/performance/x86_64-rhel-9.4/thread/100%/debian-12-x86_64-20240206.cgz/lkp-gnr-2ap2/futex4/will-it-scale

commit: 
  a1e4cc0155 ("x86/percpu: Move current_task to percpu hot section")
  f3856cd343 ("x86/stackprotector: Move __stack_chk_guard to percpu hot section")

a1e4cc0155ad577a f3856cd343b6371530c9af3c973 
---------------- --------------------------- 
         %stddev     %change         %stddev
             \          |                \  
      0.84            +2.1%       0.86        perf-stat.overall.cpi
      1.19            -2.0%       1.17        perf-stat.overall.ipc
 4.785e+14            -1.9%  4.692e+14        perf-stat.total.instructions
 2.484e+09            -1.9%  2.435e+09        will-it-scale.384.threads
   6467627            -1.9%    6342224        will-it-scale.per_thread_ops
 2.484e+09            -1.9%  2.435e+09        will-it-scale.workload
     40.20            -1.3       38.94        perf-profile.calltrace.cycles-pp.futex_wait.do_futex.__x64_sys_futex.do_syscall_64.entry_SYSCALL_64_after_hwframe
     35.54            -1.3       34.29        perf-profile.calltrace.cycles-pp.__futex_wait.futex_wait.do_futex.__x64_sys_futex.do_syscall_64
     29.67            -1.2       28.44        perf-profile.calltrace.cycles-pp.futex_wait_setup.__futex_wait.futex_wait.do_futex.__x64_sys_futex
     42.56            -1.1       41.49        perf-profile.calltrace.cycles-pp.do_futex.__x64_sys_futex.do_syscall_64.entry_SYSCALL_64_after_hwframe.syscall
     46.26            -1.0       45.31        perf-profile.calltrace.cycles-pp.__x64_sys_futex.do_syscall_64.entry_SYSCALL_64_after_hwframe.syscall
     31.33            -0.8       30.52        perf-profile.calltrace.cycles-pp.entry_SYSCALL_64.syscall
     65.81            -0.7       65.08        perf-profile.calltrace.cycles-pp.entry_SYSCALL_64_after_hwframe.syscall
     62.78            -0.7       62.12        perf-profile.calltrace.cycles-pp.do_syscall_64.entry_SYSCALL_64_after_hwframe.syscall
      4.94            -0.3        4.67        perf-profile.calltrace.cycles-pp.futex_q_unlock.futex_wait_setup.__futex_wait.futex_wait.do_futex
      2.62            -0.2        2.42        perf-profile.calltrace.cycles-pp.get_futex_key.futex_wait_setup.__futex_wait.futex_wait.do_futex
      3.62            -0.1        3.49        perf-profile.calltrace.cycles-pp.futex_hash.futex_q_lock.futex_wait_setup.__futex_wait.futex_wait
      1.69            -0.1        1.56        perf-profile.calltrace.cycles-pp.testcase
      1.06            -0.0        1.04        perf-profile.calltrace.cycles-pp.syscall_exit_to_user_mode_prepare.syscall_exit_to_user_mode.do_syscall_64.entry_SYSCALL_64_after_hwframe.syscall
      1.91            +0.1        1.99        perf-profile.calltrace.cycles-pp.syscall_return_via_sysret.syscall
      2.21            +0.1        2.34        perf-profile.calltrace.cycles-pp.x64_sys_call.do_syscall_64.entry_SYSCALL_64_after_hwframe.syscall
     90.29            +0.2       90.49        perf-profile.calltrace.cycles-pp.syscall
      1.13            +2.6        3.68        perf-profile.calltrace.cycles-pp.entry_SYSCALL_64_safe_stack.syscall
     30.76            -1.3       29.47        perf-profile.children.cycles-pp.futex_wait_setup
     36.03            -1.3       34.77        perf-profile.children.cycles-pp.__futex_wait
     40.41            -1.3       39.16        perf-profile.children.cycles-pp.futex_wait
     43.41            -1.0       42.37        perf-profile.children.cycles-pp.do_futex
     46.83            -0.9       45.91        perf-profile.children.cycles-pp.__x64_sys_futex
     66.21            -0.7       65.55        perf-profile.children.cycles-pp.entry_SYSCALL_64_after_hwframe
     63.79            -0.7       63.13        perf-profile.children.cycles-pp.do_syscall_64
      7.52            -0.3        7.20        perf-profile.children.cycles-pp.entry_SYSRETQ_unsafe_stack
      5.16            -0.3        4.90        perf-profile.children.cycles-pp.futex_q_unlock
      2.79            -0.2        2.58        perf-profile.children.cycles-pp.get_futex_key
      1.99            -0.1        1.84        perf-profile.children.cycles-pp.testcase
      3.78            -0.1        3.64        perf-profile.children.cycles-pp.futex_hash
      0.56            -0.0        0.51        perf-profile.children.cycles-pp.syscall@plt
      2.18            +0.1        2.25        perf-profile.children.cycles-pp.syscall_return_via_sysret
      2.49            +0.1        2.62        perf-profile.children.cycles-pp.x64_sys_call
     17.32            +0.6       17.89        perf-profile.children.cycles-pp.entry_SYSCALL_64
      1.16            +1.5        2.70        perf-profile.children.cycles-pp.entry_SYSCALL_64_safe_stack
     13.43            -0.7       12.74        perf-profile.self.cycles-pp.futex_wait_setup
     17.52            -0.4       17.13        perf-profile.self.cycles-pp.syscall
      7.25            -0.3        6.94        perf-profile.self.cycles-pp.entry_SYSRETQ_unsafe_stack
      4.87 ±  2%      -0.3        4.62        perf-profile.self.cycles-pp.futex_q_unlock
      2.51            -0.2        2.32        perf-profile.self.cycles-pp.get_futex_key
      3.55            -0.1        3.42        perf-profile.self.cycles-pp.futex_hash
      1.76            -0.1        1.64        perf-profile.self.cycles-pp.testcase
      0.25            -0.0        0.23        perf-profile.self.cycles-pp.syscall@plt
      2.61            +0.0        2.66        perf-profile.self.cycles-pp.entry_SYSCALL_64_after_hwframe
      2.18            +0.1        2.25        perf-profile.self.cycles-pp.syscall_return_via_sysret
      3.42            +0.1        3.53        perf-profile.self.cycles-pp.__x64_sys_futex
      2.81            +0.1        2.93        perf-profile.self.cycles-pp._raw_spin_lock
      2.20            +0.1        2.33        perf-profile.self.cycles-pp.x64_sys_call
      4.62            +0.2        4.77        perf-profile.self.cycles-pp.do_syscall_64
      3.27            +0.2        3.49        perf-profile.self.cycles-pp.do_futex
      1.14            +0.5        1.68        perf-profile.self.cycles-pp.entry_SYSCALL_64_safe_stack
      3.30            +0.9        4.24        perf-profile.self.cycles-pp.entry_SYSCALL_64




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