Displaying 3 results from an estimated 3 matches for "2ad8d8d".
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2ad8db3
2017 Feb 08
0
[PATCH 2/2] locking/mutex, rwsem: Reduce vcpu_is_preempted() calling frequency
...56 iterations).
*/
if (!owner->on_cpu || need_resched() ||
- vcpu_is_preempted(task_cpu(owner))) {
+ (!(++loop & 0xff) && vcpu_is_preempted(task_cpu(owner)))) {
ret = false;
break;
}
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 2ad8d8d..7a884a6 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -351,6 +351,7 @@ static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem)
static noinline bool rwsem_spin_on_owner(struct rw_semaphore *sem)
{
struct task_struct *owner = READ_ONCE(sem->owner);...
2017 Feb 08
4
[PATCH 1/2] x86/paravirt: Don't make vcpu_is_preempted() a callee-save function
It was found when running fio sequential write test with a XFS ramdisk
on a 2-socket x86-64 system, the %CPU times as reported by perf were
as follows:
71.27% 0.28% fio [k] down_write
70.99% 0.01% fio [k] call_rwsem_down_write_failed
69.43% 1.18% fio [k] rwsem_down_write_failed
65.51% 54.57% fio [k] osq_lock
9.72% 7.99% fio [k] __raw_callee_save___kvm_vcpu_is_preempted
4.16%
2017 Feb 08
4
[PATCH 1/2] x86/paravirt: Don't make vcpu_is_preempted() a callee-save function
It was found when running fio sequential write test with a XFS ramdisk
on a 2-socket x86-64 system, the %CPU times as reported by perf were
as follows:
71.27% 0.28% fio [k] down_write
70.99% 0.01% fio [k] call_rwsem_down_write_failed
69.43% 1.18% fio [k] rwsem_down_write_failed
65.51% 54.57% fio [k] osq_lock
9.72% 7.99% fio [k] __raw_callee_save___kvm_vcpu_is_preempted
4.16%