search for: __mutex_owner

Displaying 3 results from an estimated 3 matches for "__mutex_owner".

2017 Feb 08
0
[PATCH 2/2] locking/mutex, rwsem: Reduce vcpu_is_preempted() calling frequency
.....2ece0c4 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -423,6 +423,7 @@ bool mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner, struct ww_acquire_ctx *ww_ctx, struct mutex_waiter *waiter) { bool ret = true; + int loop = 0; rcu_read_lock(); while (__mutex_owner(lock) == owner) { @@ -436,9 +437,11 @@ bool mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner, /* * Use vcpu_is_preempted to detect lock holder preemption issue. + * As vcpu_is_preempted is more costly to use, it is called at + * a reduced frequencey (once every 256 ite...
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%