Re: [NT] Quantum of interrupted process

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

From: Bill McKenzie (bill.mckenzie_at_nospam.conexant.com)
Date: 05/18/04 

Date: Tue, 18 May 2004 09:31:43 -0500

Processes aren't scheduled, the thread is the scheduled entity in Windows
operating systems. Also, I believe a thread is not handed a time slice
until it is dispatched to run, so your scenario below where P2 is skipped
would never happen. However, you also have no view into the order in which
threads are scheduled so it shouldn't really matter either way unless you
are worried about starvation. I believe any interruption time that a thread
incurres will count against it's time slice. 

-- 
Bill McKenzie
Software Engineer - Prism 802.11 Wireless Solutions
Conexant Systems, Inc.
"G. Turgij" <t0urguy@hotmail.com> wrote in message
news:c868tj$2kc$01$2@news.t-online.com...
> Hi there!
>
> Let's say we have three processes: P1, P2 and P3
> They are scheduled to run in this order: P1 -> P2 -> P3
> Execution is running in P1 and its quantum (Q1) is almost
> over.
>
> Now P1 is interrupted and control is passed to a KMD while IRQL
> changes to DISPATCH_LEVEL (or let's say a spinlock is active)...
>
> Now my question:
> Will Q1 be frozen and continued from the point when the interrupt
> occured, even if the kernel-mode code takes very long to execute?
>
> In other words: If Q1 and even Q2 would theoretically have passed
> during the kernel operation, will the scheduler switch to P3 with Q3
> set to what's left for P3  - OR - does it return to P1 with the original
> (frozen) Q1?
>
>
> Thanks in advance!
>
> > Gregor Turgij <
>
>

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