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From: Robert Watson <rwatson@FreeBSD.org>
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To: Barney Cordoba <barney_cordoba@yahoo.com>
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Cc: jeff@FreeBSD.org, freebsd-current@freebsd.org,
	Ivan Voras <ivoras@freebsd.org>
Subject: Re: Binding timer interrupt to a cpu core
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On Wed, 21 Jan 2009, Barney Cordoba wrote:

>> Interrupts can be bound to CPUs but only by using APIs within the kernel 
>> (there's no userland utility for it).
>
> I'm asking HOW, to do it within the kernel.
>
> When I said timer, I meant software interrupts created with timeout()

This is supported in FreeBSD 8.x, but not yet 7.x and earlier.  Whoever added 
this support failed to update the timeout(9) man page, however, so the source 
is the reference -- take a look at callout.h, but gist is that you can call 
callout_reset_on(), callout_reset_curcpu(), callout_schedule_on(), and 
callout_schedule_curcpu() to specify the next CPU that the callout should run 
on.

(Jeff Roberson CC'd to remind him that he wants to update timeout.9, or find 
someone to help him do that, so that it includes the new interfaces).

Robert N M Watson
Computer Laboratory
University of Cambridge