Re: svn commit: r222866 - head/sys/x86/x86

2011-06-21 Thread Jung-uk Kim
On Tuesday 21 June 2011 11:56 am, John Baldwin wrote: > On Tuesday, June 21, 2011 11:48:55 am Jung-uk Kim wrote: > > On Tuesday 21 June 2011 09:10 am, John Baldwin wrote: > > > On Monday, June 20, 2011 7:41:00 pm Jung-uk Kim wrote: > > > > My questions to you: > > > > > > > > a) Why do we care TSC

Re: svn commit: r222866 - head/sys/x86/x86

2011-06-21 Thread John Baldwin
On Tuesday, June 21, 2011 11:48:55 am Jung-uk Kim wrote: > On Tuesday 21 June 2011 09:10 am, John Baldwin wrote: > > On Monday, June 20, 2011 7:41:00 pm Jung-uk Kim wrote: > > > My questions to you: > > > > > > a) Why do we care TSC timecounter when it is not invariant where > > > we *know* it is u

Re: svn commit: r222866 - head/sys/x86/x86

2011-06-21 Thread Jung-uk Kim
On Tuesday 21 June 2011 09:10 am, John Baldwin wrote: > On Monday, June 20, 2011 7:41:00 pm Jung-uk Kim wrote: > > My questions to you: > > > > a) Why do we care TSC timecounter when it is not invariant where > > we *know* it is unusable and set to negative quality? > > What if the user knows they

Re: svn commit: r222866 - head/sys/x86/x86

2011-06-21 Thread John Baldwin
On Monday, June 20, 2011 7:41:00 pm Jung-uk Kim wrote: > My questions to you: > > a) Why do we care TSC timecounter when it is not invariant where we > *know* it is unusable and set to negative quality? What if the user knows they will not enable CPU throttling so for them the TSC is safe? In

Re: svn commit: r222866 - head/sys/x86/x86

2011-06-20 Thread Jung-uk Kim
On Saturday 18 June 2011 08:05 am, Bruce Evans wrote: > Long ago, On Wed, 8 Jun 2011, Jung-uk Kim wrote: > > On Wednesday 08 June 2011 04:55 pm, Bruce Evans wrote: > >> On Wed, 8 Jun 2011, Jung-uk Kim wrote: > >>> Log: > >>> Introduce low-resolution TSC timecounter "TSC-low". It > >>> replaces th

Re: svn commit: r222866 - head/sys/x86/x86

2011-06-20 Thread Bruce Evans
On Mon, 20 Jun 2011, Peter Jeremy wrote: On 2011-Jun-18 22:05:06 +1000, Bruce Evans wrote: My clock measurement program (mostly an old program by Wollman) shows the following histogram of times for a non-invariant TSC timecounter on a 2GHz UP system: % min 273, max 265102, mean 273.998217, st

Re: svn commit: r222866 - head/sys/x86/x86

2011-06-20 Thread Peter Jeremy
On 2011-Jun-18 22:05:06 +1000, Bruce Evans wrote: >My clock measurement program (mostly an old program by Wollman) shows >the following histogram of times for a non-invariant TSC timecounter >on a 2GHz UP system: > >% min 273, max 265102, mean 273.998217, std 79.069534 >% 1th: 273 (1727219 observa

Re: svn commit: r222866 - head/sys/x86/x86

2011-06-18 Thread Bruce Evans
Long ago, On Wed, 8 Jun 2011, Jung-uk Kim wrote: On Wednesday 08 June 2011 04:55 pm, Bruce Evans wrote: On Wed, 8 Jun 2011, Jung-uk Kim wrote: Log: Introduce low-resolution TSC timecounter "TSC-low". It replaces the normal TSC timecounter if TSC frequency is higher than ~4.29 MHz (or 2^32-1

Re: svn commit: r222866 - head/sys/x86/x86

2011-06-08 Thread Jung-uk Kim
On Wednesday 08 June 2011 04:55 pm, Bruce Evans wrote: > On Wed, 8 Jun 2011, Jung-uk Kim wrote: > > Log: > > Introduce low-resolution TSC timecounter "TSC-low". It replaces > > the normal TSC timecounter if TSC frequency is higher than ~4.29 > > MHz (or 2^32-1 Hz) or > > Off by a factor of 1024.

Re: svn commit: r222866 - head/sys/x86/x86

2011-06-08 Thread Bruce Evans
On Wed, 8 Jun 2011, Jung-uk Kim wrote: Log: Introduce low-resolution TSC timecounter "TSC-low". It replaces the normal TSC timecounter if TSC frequency is higher than ~4.29 MHz (or 2^32-1 Hz) or Off by a factor of 1024. multiple CPUs are present. The "TSC-low" frequency is always lower

svn commit: r222866 - head/sys/x86/x86

2011-06-08 Thread Jung-uk Kim
Author: jkim Date: Wed Jun 8 19:38:31 2011 New Revision: 222866 URL: http://svn.freebsd.org/changeset/base/222866 Log: Introduce low-resolution TSC timecounter "TSC-low". It replaces the normal TSC timecounter if TSC frequency is higher than ~4.29 MHz (or 2^32-1 Hz) or multiple CPUs are pr