dlan17/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

s390/preempt: Optimize __preempt_count_dec_and_test()

Browse Source 
Use __atomic_add_const_and_test() within __preempt_count_dec_and_test().
With this it is possible to decrease preempt_count by one and test if
need_resched is set with one instruction, if the compiler has support for
flag output operand constraints.

Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
This commit is contained in:
Heiko Carstens
2024-12-15 16:19:03 +01:00
committed by Alexander Gordeev
parent a53f5d247e
commit 5c9e37e523
1 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
arch/s390/include/asm/preempt.h
+1 -1
View File
@@ -87,7 +87,7 @@ static __always_inline void __preempt_count_sub(int val)
*/
static __always_inline bool __preempt_count_dec_and_test(void)
{
return __atomic_add(-1, &get_lowcore()->preempt_count) == 1;
return __atomic_add_const_and_test(-1, &get_lowcore()->preempt_count);
}
/*