Messages in this thread | | | From | Daniel Vacek <> | Date | Mon, 5 Nov 2018 16:41:56 +0100 | Subject | Re: [PATCH] tsc: make calibration refinement more robust |
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On Sat, Nov 3, 2018 at 11:04 AM, Thomas Gleixner <tglx@linutronix.de> wrote: > Daniel, > > On Fri, 2 Nov 2018, Daniel Vacek wrote: >> On Thu, Nov 1, 2018 at 4:34 PM, Thomas Gleixner <tglx@linutronix.de> wrote: >> >> -#define MAX_RETRIES 5 >> >> -#define SMI_TRESHOLD 50000 >> >> +#define MAX_RETRIES 5 >> >> +#define TSC_THRESHOLD (tsc_khz >> 5) >> > >> > This breaks pit_hpet_ptimer_calibrate_cpu() because at that point tsc_hkz is 0. >> >> That did not show up with my testing, sorry. I guess >> pit_calibrate_tsc() never failed for me. Hmm, actually it looks like >> quick_pit_calibrate() does the job for me so >> pit_hpet_ptimer_calibrate_cpu() is likely not even called. > > Right. It's only called when quick calibration fails. Testing does not > replace code inspection :)
Agreed. I was not 100% sure about this early init and order of execution as it's dynamically changed with x86_platform.calibrate_cpu and x86_platform.calibrate_tsc. Thanks again for the review, Thomas.
> Can you please avoid hiding the logic in a macro? Just use a local > variable: > > u64 thresh = tsc_khz ? tsc_khz >> 5 : TSC_DEFAULT_THRESHOLD; > > and use that in the comparison.
Sweet, I'll do that :)
--nX
> Thanks, > > tglx
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