[PATCH 2/2] sched: make nr_iowait_cpu() return "unsigned int"

From: Alexey Dobriyan
Date: Wed Mar 11 2020 - 17:08:37 EST


Same logic: 2^32 threads stuck waiting in runqueue implies
2^32+ processes total which is absurd.

Per-runqueue ->nr_iowait member being 32-bit hints that it is
correct change!

Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---

fs/proc/stat.c | 2 +-
include/linux/sched/stat.h | 4 ++--
kernel/sched/core.c | 6 +++---
3 files changed, 6 insertions(+), 6 deletions(-)

--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -198,7 +198,7 @@ static int show_stat(struct seq_file *p, void *v)
"btime %llu\n"
"processes %lu\n"
"procs_running %u\n"
- "procs_blocked %lu\n",
+ "procs_blocked %u\n",
nr_context_switches(),
(unsigned long long)boottime.tv_sec,
total_forks,
--- a/include/linux/sched/stat.h
+++ b/include/linux/sched/stat.h
@@ -18,8 +18,8 @@ DECLARE_PER_CPU(unsigned long, process_counts);
extern int nr_processes(void);
unsigned int nr_running(void);
extern bool single_task_running(void);
-extern unsigned long nr_iowait(void);
-extern unsigned long nr_iowait_cpu(int cpu);
+unsigned int nr_iowait(void);
+unsigned int nr_iowait_cpu(int cpu);

static inline int sched_info_on(void)
{
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3436,7 +3436,7 @@ unsigned long long nr_context_switches(void)
* it does become runnable.
*/

-unsigned long nr_iowait_cpu(int cpu)
+unsigned int nr_iowait_cpu(int cpu)
{
return atomic_read(&cpu_rq(cpu)->nr_iowait);
}
@@ -3471,9 +3471,9 @@ unsigned long nr_iowait_cpu(int cpu)
* Task CPU affinities can make all that even more 'interesting'.
*/

-unsigned long nr_iowait(void)
+unsigned int nr_iowait(void)
{
- unsigned long i, sum = 0;
+ unsigned int i, sum = 0;

for_each_possible_cpu(i)
sum += nr_iowait_cpu(i);