Re: [patch 20/47] x86: Remove useless reinitialization of irqdescriptors
From: Thomas Gleixner
Date: Sun Oct 03 2010 - 14:27:14 EST
On Sun, 3 Oct 2010, Eric W. Biederman wrote:
> Thomas Gleixner <tglx@xxxxxxxxxxxxx> writes:
>
> > The descriptors are already initialized in exaclty this way.
>
> They aren't only status is initialized exactly that way.
Err.
SPARSE_IRQ=n:
struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
[0 ... NR_IRQS-1] = {
.status = IRQ_DISABLED,
.chip = &no_irq_chip,
.handle_irq = handle_bad_irq,
.depth = 1,
.lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
}
};
So action == NULL and depth == 1
SPARSE_IRQ=y:
allocates with kzalloc which makes action == NULL and depth is set in
the init function to 1.
That's true for mainline and after the rework as well.
Thanks,
tglx
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