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From: madprops@gmx.net
To: linux-mips@linux-mips.org
Subject: Timer interrupts
Date: Fri, 16 Dec 2005 16:34:36 +0100 (MET)	[thread overview]
Message-ID: <2987.1134747276@www10.gmx.net> (raw)

Hi,

i'm using CP0_Count/CP0_Compare to get timer interrupts. They should be
turned off while being in kernel mode (performing syscalls / handling
tlb-misses etc) and enabled in user mode. 

Whenever a timer interrupt happens in kernel mode, the exception should be
delayed until it is switched back to the user. Up to now I set
CP0_Status(IE) to zero when entering the kernel. Does this allow pending
interrupts or are incoming interrupts totally ignored then ??

The problem that might arise (in the second case) is that CP0_Count reaches
and passes CP0_Compare while interrupts are turned off. Back in user mode,
the running user process would get an unacceptable excessive time slice.

Thanks,

Thomas





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             reply	other threads:[~2005-12-16 15:34 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-12-16 15:34 madprops [this message]
2005-12-16 16:55 ` Timer interrupts Dominic Sweetman

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