Performance monitoring?

[pll at lanminds.com]

In a message dated: Fri, 20 Dec 2002 13:47:44 EST
Derek Martin said:


>It sounded to me he was trying to get an idea of how often requests
>weren't being serviced because the disks were already busy.

Well, yeah.

>So, I dunno...  Paul, what /are/ you talking about?

I want to measue the amount of time a disk is busy doing "stuff" from 
an OS perspective.  I don't really care about it at the DMA level, 
but, if the OS/kernel makes a request, which gets sent to the DMA 
controller, and is forced into a context switch while waiting for the 
DMA controller to come back with the answer, then technically, that 
time spent doing "other stuff" while waiting, would constitute as 
"disk busy time".

Does that help?
-- 

Seeya,
Paul
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