Re: Windows CE 4.2 scheduling

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

From: Steve Maillet \(eMVP\) (nospam1_at_EntelechyConsulting.com)
Date: 08/04/04 

Date: Wed, 4 Aug 2004 09:13:16 -0400

Probably not. Depending on the CPU. On say an XScale you won't be able to
bring the SDRAM out of self refresh except via a reset. remember that when
the SDRAM is in self refresh you can't access the RAM for the code to
restore it to normal operation.

Assuming you have a solution to that it makes no difference whatsoever what
the thread quantum is as OEMIdle won't occur more often it will occur with
the same general frequency. OEMIdle is called when the scheduler has nothing
to schedule as every thread is blocked waiting on something (typically I/O
of some sort) on desktop systems there is an IDLE process that sits and
spins in a loop at the lowest possible priority so there is always something
to schedule. Unfortunately that eats up battery life in battery powered
devices so Windows CE uses the Idle capabilities of the CPU (if available)
to put the system into a low power state that can quickly restore to normal
operation upon an interrupt. 

-- 
Steve Maillet (eMVP)
smaillet at EmbeddedFusion dot com

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