diff options
| author | Bill Fischofer <bill.fischofer@linaro.org> | 2015-09-03 10:16:39 -0500 |
|---|---|---|
| committer | Maxim Uvarov <maxim.uvarov@linaro.org> | 2015-09-03 19:29:34 +0300 |
| commit | 5cdd039a6bcecae79d1fad0f2b4d52ad43c8e6d5 (patch) | |
| tree | 0a00fe4486ea8cd4f9f0a314e4e9e8e850cc8257 | |
| parent | 9c3fcc0e5c11cf8117672f63a346b80a66d72103 (diff) | |
linux-generic: schedule: fix race condition in ordered locks
Correct race condition that arises due to attempt to permit ordered locks
to be reusable. For now, ordered locks can only be used once per scheduled
event.
Signed-off-by: Bill Fischofer <bill.fischofer@linaro.org>
Reviewed-and-Tested-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
| -rw-r--r-- | platform/linux-generic/include/odp_queue_internal.h | 6 | ||||
| -rw-r--r-- | platform/linux-generic/odp_queue.c | 8 |
2 files changed, 6 insertions, 8 deletions
diff --git a/platform/linux-generic/include/odp_queue_internal.h b/platform/linux-generic/include/odp_queue_internal.h index 48576bc..0f30965 100644 --- a/platform/linux-generic/include/odp_queue_internal.h +++ b/platform/linux-generic/include/odp_queue_internal.h @@ -193,8 +193,12 @@ static inline void reorder_enq(queue_entry_t *queue, static inline void order_release(queue_entry_t *origin_qe, int count) { + uint64_t sync = odp_atomic_load_u64(&origin_qe->s.sync_out); + origin_qe->s.order_out += count; - odp_atomic_fetch_add_u64(&origin_qe->s.sync_out, count); + if (sync < origin_qe->s.order_out) + odp_atomic_fetch_add_u64(&origin_qe->s.sync_out, + origin_qe->s.order_out - sync); } static inline int reorder_deq(queue_entry_t *queue, diff --git a/platform/linux-generic/odp_queue.c b/platform/linux-generic/odp_queue.c index 15abd93..ac933da 100644 --- a/platform/linux-generic/odp_queue.c +++ b/platform/linux-generic/odp_queue.c @@ -999,12 +999,6 @@ void odp_schedule_order_unlock(odp_schedule_order_lock_t *lock ODP_UNUSED) if (!origin_qe) return; - /* Get a new sync order for reusability, and release the lock. Note - * that this must be done in this sequence to prevent race conditions - * where the next waiter could lock and unlock before we're able to - * get a new sync order since that would cause order inversion on - * subsequent locks we may perform in this ordered context. - */ - *sync = odp_atomic_fetch_inc_u64(&origin_qe->s.sync_in); + /* Release the ordered lock */ odp_atomic_fetch_inc_u64(&origin_qe->s.sync_out); } |