Messages in this thread | | | Date | Tue, 6 Feb 2024 03:04:32 -0800 | From | Kees Cook <> | Subject | Re: [PATCH] selftests/seccomp: Pin benchmark to single CPU |
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On Tue, Feb 06, 2024 at 10:16:19AM +0000, Mark Brown wrote: > On Tue, Feb 06, 2024 at 01:56:47AM -0800, Kees Cook wrote: > > > + /* Set from highest CPU down. */ > > + for (cpu = ncores - 1; cpu >= 0; cpu--) { > > + CPU_ZERO_S(setsz, setp); > > + CPU_SET_S(cpu, setsz, setp); > > Is there some particular reason to go from the highest CPU number down? > Not that it super matters but the default would be to iterate from 0 and > there's a comment but it just says the what not the why.
I was arbitrarily picking a direction and all the examples I could find started at 0, so this would be more (?) out of the way. :P
Without a cpu cgroup, I can't _exclude_ the pinned CPU from other processes, so I was pretending the last CPU will be less likely to be used.
-- Kees Cook
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