Messages in this thread | | | From | Len Brown <> | Date | Mon, 27 Nov 2023 20:39:57 -0500 | Subject | Re: [PATCH] tools/power turbostat: Fix Bzy_MHz calculation equation |
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Peng Liu, Thanks for the close read of the documentation, and the patch. I've applied it, though I re-wrote the commit message (below) to make it clear it is a documentation fix, as the code was already correct.
thanks, -Len
ps. I would have replied to your original e-mail, but there was a period where gmail dropped mail due to space limitations. No worries, as Doug said, everything is in patchwork.
tools/power turbostat: Fix Bzy_MHz documentation typo
The code calculates Bzy_MHz by multiplying TSC_delta * APERF_delta/MPERF_delta The man page erroneously showed that TSC_delta was divided.
On Thu, Nov 2, 2023 at 11:31 AM Doug Smythies <dsmythies@telus.net> wrote: > > Hi Peng and Wyes, > > Just for your information about your recent "ping"s about your turbostat patches: > > Please be aware that there is rarely any reply. There tends to be about 2 turbostat updates released per year. Your patches are in patchworks [1], as are some others, including an old one of mine from 2023.04.03 > Eventually there will be an update, and hopefully it will include all our patches. > > [1] https://patchwork.kernel.org/project/linux-pm/list/?series=&submitter=&state=&q=&archive=&delegate=107 > > ... Doug > > On 2023.10.29 08:12 Peng Liu wrote: > > > Ping > > > > On 2023/10/7 13:46, Peng Liu wrote: > >> From: Peng Liu <liupeng17@lenovo.com> > >> > >> To calculate Bzy_MHz, TSC_delta should multiply APERF_delta instead > >> of dividing it. > >> > >> Signed-off-by: Peng Liu <liupeng17@lenovo.com> > >> --- > >> tools/power/x86/turbostat/turbostat.8 | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/tools/power/x86/turbostat/turbostat.8 b/tools/power/x86/turbostat/turbostat.8 > >> index 8f08c3fd498d..1ba6340d3b3d 100644 > >> --- a/tools/power/x86/turbostat/turbostat.8 > >> +++ b/tools/power/x86/turbostat/turbostat.8 > >> @@ -370,7 +370,7 @@ below the processor's base frequency. > >> > >> Busy% = MPERF_delta/TSC_delta > >> > >> -Bzy_MHz = TSC_delta/APERF_delta/MPERF_delta/measurement_interval > >> +Bzy_MHz = TSC_delta*APERF_delta/MPERF_delta/measurement_interval > >> > >> Note that these calculations depend on TSC_delta, so they > >> are not reliable during intervals when TSC_MHz is not running at the base frequency. >
-- Len Brown, Intel
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