Commit 6f28c4a8 authored by Dawei Li's avatar Dawei Li Committed by Thomas Gleixner
Browse files

cpuidle: Avoid explicit cpumask allocation on stack 



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.

Use cpumask_first_and_and() and cpumask_weight_and() to avoid the need
for a temporary cpumask on the stack.

Signed-off-by: default avatarDawei Li <dawei.li@shingroup.cn>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240416085454.3547175-8-dawei.li@shingroup.cn
parent a7fb69ff

drivers/cpuidle/coupled.c

+3 −10
Original line number Diff line number Diff line
@@ -439,13 +439,8 @@ static int cpuidle_coupled_clear_pokes(int cpu) 


static bool cpuidle_coupled_any_pokes_pending(struct cpuidle_coupled *coupled)

{

	cpumask_t cpus;

	int ret;



	cpumask_and(&cpus, cpu_online_mask, &coupled->coupled_cpus);

	ret = cpumask_and(&cpus, &cpuidle_coupled_poke_pending, &cpus);



	return ret;

	return cpumask_first_and_and(cpu_online_mask, &coupled->coupled_cpus,

				     &cpuidle_coupled_poke_pending) < nr_cpu_ids;

}



/**
@@ -626,9 +621,7 @@ int cpuidle_enter_state_coupled(struct cpuidle_device *dev, 


static void cpuidle_coupled_update_online_cpus(struct cpuidle_coupled *coupled)

{

	cpumask_t cpus;

	cpumask_and(&cpus, cpu_online_mask, &coupled->coupled_cpus);

	coupled->online_count = cpumask_weight(&cpus);

	coupled->online_count = cpumask_weight_and(cpu_online_mask, &coupled->coupled_cpus);

}



/**