On 02/15, Raghavendra K T wrote:
On 02/13/2015 09:02 PM, Oleg Nesterov wrote:
@@ -772,7 +773,8 @@ __visible void kvm_lock_spinning(struct arch_spinlock
*lock, __ticket_t want)
* check again make sure it didn't become free while
* we weren't looking.
*/
- if
On 02/13/2015 09:02 PM, Oleg Nesterov wrote:
On 02/13, Raghavendra K T wrote:
@@ -164,7 +161,7 @@ static inline int arch_spin_is_locked(arch_spinlock_t *lock)
{
struct __raw_tickets tmp = READ_ONCE(lock-tickets);
- return tmp.tail != tmp.head;
+ return tmp.tail !=
On 02/13, Oleg Nesterov wrote:
On 02/13, Raghavendra K T wrote:
@@ -772,7 +773,8 @@ __visible void kvm_lock_spinning(struct arch_spinlock
*lock, __ticket_t want)
* check again make sure it didn't become free while
* we weren't looking.
*/
- if
On 02/13, Raghavendra K T wrote:
@@ -164,7 +161,7 @@ static inline int arch_spin_is_locked(arch_spinlock_t
*lock)
{
struct __raw_tickets tmp = READ_ONCE(lock-tickets);
- return tmp.tail != tmp.head;
+ return tmp.tail != (tmp.head ~TICKET_SLOWPATH_FLAG);
}
Well, this can
Paravirt spinlock clears slowpath flag after doing unlock.
As explained by Linus currently it does:
prev = *lock;
add_smp(lock-tickets.head, TICKET_LOCK_INC);
/* add_smp() is a full mb() */
if (unlikely(lock-tickets.tail
