Messages in this thread | | | Date | Mon, 27 Apr 2015 21:45:12 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue |
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On Mon, Apr 27, 2015 at 09:21:34PM +0200, Denys Vlasenko wrote: > On 04/27/2015 09:11 PM, Borislav Petkov wrote: > > A: 709.528485252 seconds time elapsed ( +- 0.02% ) > > B: 708.976557288 seconds time elapsed ( +- 0.04% ) > > C: 709.312844791 seconds time elapsed ( +- 0.02% ) > > D: 709.400050112 seconds time elapsed ( +- 0.01% ) > > E: 708.914562508 seconds time elapsed ( +- 0.06% ) > > F: 709.602255085 seconds time elapsed ( +- 0.02% ) > > That's about 0.2% variance. Very small.
Right, I'm doubtful this is the right workload for this. And actually if even any workload would show any serious difference. Perhaps it all doesn't really matter and we shouldn't do anything at all.
> Sounds obvious, but. Did you try running a test several times?
All runs so far are done with perf state ... --repeat 10 so, 10 kernel builds and results are averaged.
> Maybe you are measuring random noise.
Yeah. Last exercise tomorrow. Let's see what those numbers would look like.
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply. --
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