diff options
| author | Ingo Molnar <mingo@kernel.org> | 2015-03-05 20:52:18 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-03-05 20:52:18 +0100 |
| commit | 33ca8a53f262b4af40611bea331b8c87d133af72 (patch) | |
| tree | d6468c820a556c4915bcb5b761204a0fb19e8225 /arch/x86/kernel/kvm.c | |
| parent | db2dcb4f91d5fec5c346a82c309187ee821e2495 (diff) | |
| parent | 13a7a6ac0a11197edcd0f756a035f472b42cdf8b (diff) | |
Merge tag 'v4.0-rc2' into irq/core, to refresh the tree before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/kvm.c')
| -rw-r--r-- | arch/x86/kernel/kvm.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 94f643484300..e354cc6446ab 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -609,7 +609,7 @@ static inline void check_zero(void) u8 ret; u8 old; - old = ACCESS_ONCE(zero_stats); + old = READ_ONCE(zero_stats); if (unlikely(old)) { ret = cmpxchg(&zero_stats, old, 0); /* This ensures only one fellow resets the stat */ @@ -727,6 +727,7 @@ __visible void kvm_lock_spinning(struct arch_spinlock *lock, __ticket_t want) int cpu; u64 start; unsigned long flags; + __ticket_t head; if (in_nmi()) return; @@ -768,11 +769,15 @@ __visible void kvm_lock_spinning(struct arch_spinlock *lock, __ticket_t want) */ __ticket_enter_slowpath(lock); + /* make sure enter_slowpath, which is atomic does not cross the read */ + smp_mb__after_atomic(); + /* * check again make sure it didn't become free while * we weren't looking. */ - if (ACCESS_ONCE(lock->tickets.head) == want) { + head = READ_ONCE(lock->tickets.head); + if (__tickets_equal(head, want)) { add_stats(TAKEN_SLOW_PICKUP, 1); goto out; } @@ -803,8 +808,8 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) add_stats(RELEASED_SLOW, 1); for_each_cpu(cpu, &waiting_cpus) { const struct kvm_lock_waiting *w = &per_cpu(klock_waiting, cpu); - if (ACCESS_ONCE(w->lock) == lock && - ACCESS_ONCE(w->want) == ticket) { + if (READ_ONCE(w->lock) == lock && + READ_ONCE(w->want) == ticket) { add_stats(RELEASED_SLOW_KICKED, 1); kvm_kick_cpu(cpu); break; |