Re: TSC timekeeping and cpu states

2017-08-15 Thread Ian Smith
On Mon, 14 Aug 2017 09:48:07 -0700, Kevin Oberman wrote: > On Mon, Aug 14, 2017 at 8:38 AM, Ian Smith wrote: [..] > > > > As far as possible TSC impact, I think older processors had TSC > > > > issues when not all cores ran with the same clock speed. That said, > > >

Re: TSC timekeeping and cpu states

2017-08-14 Thread Kevin Oberman
On Mon, Aug 14, 2017 at 8:38 AM, Ian Smith wrote: > On Mon, 14 Aug 2017 17:16:22 +1000, Aristedes Maniatis wrote: > > > On 14/8/17 3:08PM, Kevin Oberman wrote: > > > Again, the documentation lags reality. The default was changed for > > > 11.0. It is still conservative.

Re: TSC timekeeping and cpu states

2017-08-14 Thread Alexander Motin
On 14.08.2017 18:38, Ian Smith wrote: > On Mon, 14 Aug 2017 17:16:22 +1000, Aristedes Maniatis wrote: > > On 14/8/17 3:08PM, Kevin Oberman wrote: > > > Again, the documentation lags reality. The default was changed for > > > 11.0. It is still conservative. In ALMOST all cases, Cmax will yield

Re: TSC timekeeping and cpu states

2017-08-14 Thread Ian Smith
On Mon, 14 Aug 2017 17:16:22 +1000, Aristedes Maniatis wrote: > On 14/8/17 3:08PM, Kevin Oberman wrote: > > Again, the documentation lags reality. The default was changed for > > 11.0. It is still conservative. In ALMOST all cases, Cmax will yield > > the bast results. However, on large

Re: TSC timekeeping and cpu states

2017-08-14 Thread Aristedes Maniatis
On 14/8/17 3:08PM, Kevin Oberman wrote: > Again, the documentation lags reality. The default was changed for 11.0. It > is still conservative. In ALMOST all cases, Cmax will yield the bast results. > However, on large systems with many cores, Cmax will trigger very poor > results, so the

Re: TSC timekeeping and cpu states

2017-08-13 Thread Kevin Oberman
On Sun, Aug 13, 2017 at 8:25 PM, Aristedes Maniatis wrote: > I note that in FreeBSD 11, we now have this: > > # grep performance_cx_lowest /etc/defaults/rc.conf > performance_cx_lowest="C2" # Online CPU idle state > > However this wiki page suggests that C1 is the

TSC timekeeping and cpu states

2017-08-13 Thread Aristedes Maniatis
I note that in FreeBSD 11, we now have this: # grep performance_cx_lowest /etc/defaults/rc.conf performance_cx_lowest="C2" # Online CPU idle state However this wiki page suggests that C1 is the default https://wiki.freebsd.org/TuningPowerConsumption Are these inconsistent? I