Re: Meeting minutes 20060727

["Jose R. Santos" <jrs at us dot ibm dot com>]

Frank Ch. Eigler wrote:
> Hi -
>
> On Thu, Aug 03, 2006 at 03:49:42PM -0500, Jose R. Santos wrote:
>
> > [...]  My point is that printing raw cycles will have less of an
> > impact than the calculations needed for gettimeofday.  [...]
>
> Nothing is keeping you from tracing the value of get_cycles() instead
> of a higher level figure.
>
> - FChE
>   
Actually, in the email that was directed at Masami-san I stated two 
scenarios that prevent us just using get_cycles().  One is processors 
that support frequency scaling and the second one is virtulized 
environments like Xen or Power5 micro partitions.  This was something 
that Masami-san and myself were discussing at OLS, as one of his main 
concerns with LKET the performance impact of do_gettimeofday() as a 
timestamp mechanism.  The things that I wrote on my email to Masami-san 
were a continuation of those discussion we had at OLS in an effort to 
standardize the tracing mechanism.

-JRS