Mailing List Archive

The following commit has been merged into the irq/core branch of tip:

Commit-ID: 6f28c4a852fab8bd759a383149dfd30511477249
Gitweb: https://git.kernel.org/tip/6f28c4a852fab8bd759a383149dfd30511477249
Author: Dawei Li <dawei.li@shingroup.cn>
AuthorDate: Tue, 16 Apr 2024 16:54:54 +08:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Wed, 24 Apr 2024 21:23:49 +02:00

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: Dawei Li <dawei.li@shingroup.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240416085454.3547175-8-dawei.li@shingroup.cn

---
drivers/cpuidle/coupled.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c
index 9acde71..bb8761c 100644
--- a/drivers/cpuidle/coupled.c
+++ b/drivers/cpuidle/coupled.c
@@ -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 @@ out:

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);
}

/**