kernel_optimize_test/kernel/irq/migration.c
Daniel Walker 89d0cf01c0 [PATCH] invert irq/migration.c brach prediction
If you get to that point in the code it means that desc->move_irq is set,
pending_irq_cpumask[irq] and cpu_online_map should have a value.  Still
pretty good chance anding those two you'll still have a value.  So these
two branch predictors should be inverted.

Signed-off-by: Daniel Walker <dwalker@mvista.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:43:04 -07:00

63 lines
1.4 KiB
C

#include <linux/irq.h>
void set_pending_irq(unsigned int irq, cpumask_t mask)
{
irq_desc_t *desc = irq_desc + irq;
unsigned long flags;
spin_lock_irqsave(&desc->lock, flags);
desc->move_irq = 1;
pending_irq_cpumask[irq] = mask;
spin_unlock_irqrestore(&desc->lock, flags);
}
void move_native_irq(int irq)
{
cpumask_t tmp;
irq_desc_t *desc = irq_descp(irq);
if (likely(!desc->move_irq))
return;
/*
* Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
*/
if (CHECK_IRQ_PER_CPU(desc->status)) {
WARN_ON(1);
return;
}
desc->move_irq = 0;
if (unlikely(cpus_empty(pending_irq_cpumask[irq])))
return;
if (!desc->handler->set_affinity)
return;
assert_spin_locked(&desc->lock);
cpus_and(tmp, pending_irq_cpumask[irq], cpu_online_map);
/*
* If there was a valid mask to work with, please
* do the disable, re-program, enable sequence.
* This is *not* particularly important for level triggered
* but in a edge trigger case, we might be setting rte
* when an active trigger is comming in. This could
* cause some ioapics to mal-function.
* Being paranoid i guess!
*/
if (likely(!cpus_empty(tmp))) {
if (likely(!(desc->status & IRQ_DISABLED)))
desc->handler->disable(irq);
desc->handler->set_affinity(irq,tmp);
if (likely(!(desc->status & IRQ_DISABLED)))
desc->handler->enable(irq);
}
cpus_clear(pending_irq_cpumask[irq]);
}