> -----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? Thanks, Yazen
