cpumask: make cpumask_size() return "unsigned int"

PATCH Applied Alexey Dobriyan 1 participant 1 message Dec 4, 2017

Subsystems (2)

Scheduler Bitmap API

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Alexey Dobriyan

author

2017-12-04 16:55 UTC #0 lore raw

PATCH 1/1 cpumask: make cpumask_size() return "unsigned int"

CPUmasks are never big enough to warrant 64-bit code.

Space savings:

add/remove: 0/0 grow/shrink: 1/4 up/down: 3/-17 (-14)
Function old new delta
sched_init_numa 1530 1533 +3
compat_sys_sched_setaffinity 160 159 -1
sys_sched_getaffinity 197 195 -2
sys_sched_setaffinity 183 176 -7
compat_sys_sched_getaffinity 179 172 -7

Signed-off-by Alexey Dobriyan <[email protected]>

---

 include/linux/cpumask.h |    2 +-
 kernel/compat.c         |    2 +-
 kernel/sched/core.c     |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

include/linux/cpumask.h +1 -1

@@ -640,7 +640,7 @@ static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
 /**
  * cpumask_size - size to allocate for a 'struct cpumask' in bytes
  */
-static inline size_t cpumask_size(void)
+static inline unsigned int cpumask_size(void)
 {
 	return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long);
 }

kernel/compat.c +1 -1

@@ -355,7 +355,7 @@ COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t,  pid, unsigned int, len,
 
 	ret = sched_getaffinity(pid, mask);
 	if (ret == 0) {
-		size_t retlen = min_t(size_t, len, cpumask_size());
+		unsigned int retlen = min(len, cpumask_size());
 
 		if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
 			ret = -EFAULT;

kernel/sched/core.c +1 -1

@@ -4799,7 +4799,7 @@ SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
 
 	ret = sched_getaffinity(pid, mask);
 	if (ret == 0) {
-		size_t retlen = min_t(size_t, len, cpumask_size());
+		unsigned int retlen = min(len, cpumask_size());
 
 		if (copy_to_user(user_mask_ptr, mask, retlen))
 			ret = -EFAULT;