Commit c4650ba9 authored by Dawei Li's avatar Dawei Li Committed by Andreas Larsson
Browse files

sparc/irq: Remove on-stack cpumask var 



In general it's preferable to avoid placing cpumasks on the stack, as
for large values of NR_CPUS these can consume significant amounts of
stack space and make stack overflows more likely.

- Both 2 arguments of cpumask_equal() is constant and free of change, no
  need to allocate extra cpumask variables.

- Merge cpumask_and(), cpumask_first() and cpumask_empty() into
  cpumask_first_and().

Reviewed-by: default avatarSam Ravnborg <sam@ravnborg.org>
Signed-off-by: default avatarDawei Li <dawei.li@shingroup.cn>
Reviewed-by: default avatarAndreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20240424025548.3765250-3-dawei.li@shingroup.cn


Signed-off-by: default avatarAndreas Larsson <andreas@gaisler.com>
parent 7aba3a85

arch/sparc/kernel/irq_64.c

+3 −7
Original line number Diff line number Diff line
@@ -349,17 +349,13 @@ static unsigned int sun4u_compute_tid(unsigned long imap, unsigned long cpuid) 
#ifdef CONFIG_SMP

static int irq_choose_cpu(unsigned int irq, const struct cpumask *affinity)

{

	cpumask_t mask;

	int cpuid;



	cpumask_copy(&mask, affinity);

	if (cpumask_equal(&mask, cpu_online_mask)) {

	if (cpumask_equal(affinity, cpu_online_mask)) {

		cpuid = map_to_cpu(irq);

	} else {

		cpumask_t tmp;



		cpumask_and(&tmp, cpu_online_mask, &mask);

		cpuid = cpumask_empty(&tmp) ? map_to_cpu(irq) : cpumask_first(&tmp);

		cpuid = cpumask_first_and(affinity, cpu_online_mask);

		cpuid = cpuid < nr_cpu_ids ? cpuid : map_to_cpu(irq);

	}



	return cpuid;