[lkml]   [2007]   [Oct]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] raise tsc clocksource rating
On Mon, 2007-10-29 at 20:10 -0300, Glauber de Oliveira Costa wrote:
> From: Glauber de Oliveira Costa <glauber@t60.localdomain>
> tsc is very good time source (when it does not have drifts, does not
> change it's frequency, i.e. when it works), so it should have its rating
> raised to a value greater than, or equal 400.
> Since it's being a tendency among paravirt clocksources to use values
> around 400, we should declare tsc as even better: So we use 500.

Why is the TSC better than a paravirt clocksource? In our case this is
definitely inaccurate. Paravirt clocksources should be preferred to
TSC, and both must be made available in hardware for platforms which do
not support paravirt.

Also, please cc all the paravirt developers on things related to
paravirt, especially things with such broad effect. I think 400 is a
good value for a perfect native clocksource. >400 should be reserved
for super-real (i.e. paravirt) sources that should always be chosen over
a hardware realistic implementation in a virtual environment.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-10-29 23:43    [W:0.117 / U:0.032 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site