Messages in this thread | | | Date | Sat, 28 Mar 2020 15:19:28 -0700 | From | Kees Cook <> | Subject | Re: [x86/entry] 8c5045f89b: will-it-scale.per_process_ops -12.9% regression |
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On Fri, Mar 27, 2020 at 03:40:02PM +0800, kernel test robot wrote: > Greeting, > > FYI, we noticed a -12.9% regression of will-it-scale.per_process_ops due to commit: > > > commit: 8c5045f89b181a4412b698cafc9dc257192a3a65 ("x86/entry: Enable random_kstack_offset support") > https://git.kernel.org/cgit/linux/kernel/git/kees/linux.git kspp/stack/offset/agnostic/v1 > > in testcase: will-it-scale > on test machine: 288 threads Intel(R) Xeon Phi(TM) CPU 7295 @ 1.50GHz with 80G memory > with following parameters: > > nr_task: 100% > mode: process > test: lseek1 > cpufreq_governor: performance > ucode: 0x11 > > test-description: Will It Scale takes a testcase and runs it from 1 through to n parallel copies to see if the testcase will scale. It builds both a process and threads based test in order to see any differences between the two. > test-url: https://github.com/antonblanchard/will-it-scale
Whoa. I'll take a closer look. I fail to understand how this could be happening. In this CONFIG the changes are a NOP. And that would be true for both process and thread. O_o
-- Kees Cook
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