Subject: Re: Using splsched()
To: Eduardo E. Horvath <email@example.com>
From: Jonathan Stone <jonathan@DSG.Stanford.EDU>
Date: 11/13/1997 16:14:33
>Has there been any consideration of sampling some sort of high resolution
>timer at trap/context switch time instead of using a high resolution timer
>interrupt for statistics gathering? It could elimitate the splstatclock()
>problems at the same time as improving overall timing accuracy.
1) Not all systems have such a timer. (sparcs do, but...)
2) that might work for process accouting and maybe user PC-sampling
(tho there are applications that synch to the sheduling clock, where
where you really want a different clock, if possible).
But I don't understand how you would get *kernel* profiling
data via this technique. Without that, how would we tune kernels?
(some ports do tune the MD kernel code).