Yeah, I like this patch, and I have applied it. thanks! -Len
On Fri, Jun 7, 2019 at 12:28 PM Ghannam, Yazen <[email protected]> wrote: > > > -----Original Message----- > > From: Ghannam, Yazen <[email protected]> > > Sent: Tuesday, April 23, 2019 12:53 PM > > To: Ghannam, Yazen <[email protected]>; [email protected]; > > [email protected] > > Cc: [email protected]; Len Brown <[email protected]> > > Subject: RE: [PATCH] tools/power turbostat: Make interval calculation per > > thread to reduce jitter > > > > > -----Original Message----- > > > From: [email protected] > > > <[email protected]> On Behalf Of Ghannam, Yazen > > > Sent: Monday, March 25, 2019 12:33 PM > > > To: [email protected] > > > Cc: Ghannam, Yazen <[email protected]>; [email protected]; > > > [email protected] > > > Subject: [PATCH] tools/power turbostat: Make interval calculation per > > > thread to reduce jitter > > > > > > From: Yazen Ghannam <[email protected]> > > > > > > Turbostat currently normalizes TSC and other values by dividing by an > > > interval. This interval is the delta between the start of one global > > > (all counters on all CPUs) sampling and the start of another. However, > > > this introduces a lot of jitter into the data. > > > > > > In order to reduce jitter, the interval calculation should be based on > > > timestamps taken per thread and close to the start of the thread's > > > sampling. > > > > > > Define a per thread time value to hold the delta between samples taken > > > on the thread. > > > > > > Use the timestamp taken at the beginning of sampling to calculate the > > > delta. > > > > > > Move the thread's beginning timestamp to after the CPU migration to > > > avoid jitter due to the migration. > > > > > > Use the global time delta for the average time delta. > > > > > > Signed-off-by: Yazen Ghannam <[email protected]> > > > --- > > > > Hi Len, > > > > Any comments on this patch? > > > > Hi Len, > > Just wanted to check in. Do you have any comments on this patch? > > Thanks, > Yazen -- Len Brown, Intel Open Source Technology Center
