[PATCH 04/14] powerpc/xmon: simplify xmon_batch_next_cpu()

From: Yury Norov
Date: Sat Dec 28 2024 - 13:51:02 EST


The function opencodes for_each_cpu_wrap() macro. As a loop termination
condition it uses cpumask_empty(), which is O(N), and it makes the whole
algorithm O(N^2). Switching to for_each_cpu_wrap() simplifies the logic,
and makes the algorithm linear.

Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
---
arch/powerpc/xmon/xmon.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index f4e841a36458..d7809f15dc68 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1271,11 +1271,7 @@ static int xmon_batch_next_cpu(void)
{
unsigned long cpu;

- while (!cpumask_empty(&xmon_batch_cpus)) {
- cpu = cpumask_next_wrap(smp_processor_id(), &xmon_batch_cpus,
- xmon_batch_start_cpu, true);
- if (cpu >= nr_cpu_ids)
- break;
+ for_each_cpu_wrap(cpu, &xmon_batch_cpus, xmon_batch_start_cpu) {
if (xmon_batch_start_cpu == -1)
xmon_batch_start_cpu = cpu;
if (xmon_switch_cpu(cpu))
--
2.43.0