Messages in this thread Patch in this message | | | From | Dawei Li <> | Subject | [PATCH 2/5] sparc/irq: Remove on-stack cpumask var | Date | Thu, 18 Apr 2024 18:49:46 +0800 |
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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().
Signed-off-by: Dawei Li <dawei.li@shingroup.cn> --- arch/sparc/kernel/irq_64.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c index 5280e325d4d6..bc96f1bcd2fc 100644 --- a/arch/sparc/kernel/irq_64.c +++ b/arch/sparc/kernel/irq_64.c @@ -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 ? : map_to_cpu(irq); } return cpuid; -- 2.27.0
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