Re: [PATCH] genirq: Set initial default irq affinity to just CPU0

From: Kumar Gala
Date: Mon Oct 27 2008 - 09:44:28 EST



On Oct 26, 2008, at 1:33 AM, Benjamin Herrenschmidt wrote:

On Sat, 2008-10-25 at 21:04 -0700, David Miller wrote:
But back to my original wonder, since I've always tipped off of this
generic IRQ layer cpu mask, when was it ever defaulting to zero
and causing the behvaior your powerpc guys actually want? :-)

Well, I'm not sure what Kumar wants. Most powerpc SMP setups actually
want to spread interrupts to all CPUs, and those who can't tend to just
not implement set_affinity... So Kumar must have a special case of MPIC
usage here on FSL platforms.

In any case, the platform limitations should be dealt with there or the
user could break it by manipulating affinity via /proc anyway.

By yeah, I do expect default affinity to be all CPUs and in fact, I even
have an -OLD- comment in the code that says

/* let the mpic know we want intrs. default affinitya is 0xffffffff ...

While we have the comment the code appears not to really follow it. We appear to write 1 << hard_smp_processor_id().

- k
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