diff options
author | David S. Miller <davem@davemloft.net> | 2015-03-03 21:16:48 -0500 |
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committer | David S. Miller <davem@davemloft.net> | 2015-03-03 21:16:48 -0500 |
commit | 71a83a6db6138b9d41d8a0b6b91cb59f6dc4742c (patch) | |
tree | f74b6e4e48257ec6ce40b95645ecb8533b9cc1f8 /arch/x86/xen/spinlock.c | |
parent | b97526f3ff95f92b107f0fb52cbb8627e395429b (diff) | |
parent | a6c5170d1edea97c538c81e377e56c7b5c5b7e63 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
drivers/net/ethernet/rocker/rocker.c
The rocker commit was two overlapping changes, one to rename
the ->vport member to ->pport, and another making the bitmask
expression use '1ULL' instead of plain '1'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/x86/xen/spinlock.c')
-rw-r--r-- | arch/x86/xen/spinlock.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index 23b45eb9a89c..956374c1edbc 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -41,7 +41,7 @@ static u8 zero_stats; static inline void check_zero(void) { u8 ret; - u8 old = ACCESS_ONCE(zero_stats); + u8 old = READ_ONCE(zero_stats); if (unlikely(old)) { ret = cmpxchg(&zero_stats, old, 0); /* This ensures only one fellow resets the stat */ @@ -112,6 +112,7 @@ __visible void xen_lock_spinning(struct arch_spinlock *lock, __ticket_t want) struct xen_lock_waiting *w = this_cpu_ptr(&lock_waiting); int cpu = smp_processor_id(); u64 start; + __ticket_t head; unsigned long flags; /* If kicker interrupts not initialized yet, just spin */ @@ -159,11 +160,15 @@ __visible void xen_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; } @@ -204,8 +209,8 @@ static void xen_unlock_kick(struct arch_spinlock *lock, __ticket_t next) const struct xen_lock_waiting *w = &per_cpu(lock_waiting, cpu); /* Make sure we read lock before want */ - if (ACCESS_ONCE(w->lock) == lock && - ACCESS_ONCE(w->want) == next) { + if (READ_ONCE(w->lock) == lock && + READ_ONCE(w->want) == next) { add_stats(RELEASED_SLOW_KICKED, 1); xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR); break; |