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Eduardo Horvath <eeh@netbsd.org>
08/18/2003 11:55 PM
 
        To:     Kamal R Prasad/India/IBM@IBMIN
        cc:     der Mouse <mouse@Rodents.Montreal.QC.CA>, 
tech-kern@netbsd.org
        Subject:        Re: Measuring memory to memory copy operations (+ 
interrupts, DMA)

 

On Mon, Aug 18, 2003 at 04:01:07PM +0530, Kamal R Prasad wrote:

>copyin()/copyout() can result in pages being retrieved from swap.  If
>this operation is done in the clock interrupt handler you can end up
>with a stopped clock for the duration of the disk I/O or worse, a hard
>hang as the storage driver waits for an interrupt that never arrives
>because it's currently masked.

yeah -this turned out to be a bigger problem than I imagined.
how does one pin dynamically allocated memory in libc (so that it could be 
used by an interrupt handler)?

thanks
-kamal