Messages in this thread | | | Date | Wed, 11 Oct 2023 23:42:26 +0800 | From | Feng Tang <> | Subject | Re: [PATCH v9 2/3] x86/mce: Add per-bank CMCI storm mitigation |
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On Wed, Oct 11, 2023 at 11:16:46PM +0800, Luck, Tony wrote: > > kernel test robot noticed a -8.8% regression of stress-ng.clock.ops_per_sec on: > > > > > > commit: 26bff7b04b829cccc6a97726d6398391a62e34ef ("[PATCH v9 2/3] x86/mce: Add per-bank CMCI storm mitigation") > > url: https://github.com/intel-lab-lkp/linux/commits/Tony-Luck/x86-mce-Remove-old-CMCI-storm-mitigation-code/20231005-024047 > > patch link: https://lore.kernel.org/all/20231004183623.17067-3-tony.luck@intel.com/ > > patch subject: [PATCH v9 2/3] x86/mce: Add per-bank CMCI storm mitigation > > > > testcase: stress-ng > > test machine: 64 threads 2 sockets Intel(R) Xeon(R) Gold 6346 CPU @ 3.10GHz (Ice Lake) with 256G memory > > parameters: > > > > nr_threads: 10% > > disk: 1HDD > > testtime: 60s > > fs: ext4 > > class: os > > test: clock > > 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@intel.com> > > | Closes: https://lore.kernel.org/oe-lkp/202310111637.dee70328-oliver.sang@intel.com > > Is the test injecting massive numbers of corrected memory errors? The code in this patch > is only executed when handling CMCI interrupts, or polling machine check banks (at most > once per second). > > I'm guessing this report is just because alignment of some hot path code changed.
IIRC, CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B was enabled in 0Day's kernel config for quite a while, to force each funtion's start address aligned on 64 bytes. Don't know if this has been changed recently.
Also I noticed the patch introduce a new per-cpu variable 'storm_desc", if the function address is 64B aligned, then per-cpu data alignment may be related.
Thanks, Feng
> > -Tony
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