[vsipl++] [patch] fix for profiling long processes

Jules Bergmann jules at codesourcery.com
Thu Oct 25 19:28:37 UTC 2007


Don McCoy wrote:
> When profiling over a long period of time, the raw timestamps observed
> in the profiler output have the potential to be truncated, leading to
> inaccurate results.
> 
> The error is only in how the profiler output is managed, not in the
> profile timer itself, which handles rollovers in the time source
> correctly.  The profiler output function was affected because it uses
> the 'ticks()' profile timer function to obtain the raw timestamps to
> place in the log, which were being truncated to 32-bits.
> 
> Ok to apply?

Don,

Hurray!  This seems a plausible explanation for the weird roll up (sum 
less than the parts) of time values.

One quick suggestion: can you create a 'tick_type' typedef that is 
unsigned long long.  That will help us remember not to use a 32-bit type 
again.

Otherwise this looks good, please apply.


				thanks,
				-- Jules

-- 
Jules Bergmann
CodeSourcery
jules at codesourcery.com
(650) 331-3385 x705



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