diff options
Diffstat (limited to 'include/linux/dynamic_queue_limits.h')
| -rw-r--r-- | include/linux/dynamic_queue_limits.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/include/linux/dynamic_queue_limits.h b/include/linux/dynamic_queue_limits.h index 5621547d631b..a4be70398ce1 100644 --- a/include/linux/dynamic_queue_limits.h +++ b/include/linux/dynamic_queue_limits.h @@ -73,14 +73,22 @@ static inline void dql_queued(struct dql *dql, unsigned int count) { BUG_ON(count > DQL_MAX_OBJECT); - dql->num_queued += count; dql->last_obj_cnt = count; + + /* We want to force a write first, so that cpu do not attempt + * to get cache line containing last_obj_cnt, num_queued, adj_limit + * in Shared state, but directly does a Request For Ownership + * It is only a hint, we use barrier() only. + */ + barrier(); + + dql->num_queued += count; } /* Returns how many objects can be queued, < 0 indicates over limit. */ static inline int dql_avail(const struct dql *dql) { - return dql->adj_limit - dql->num_queued; + return ACCESS_ONCE(dql->adj_limit) - ACCESS_ONCE(dql->num_queued); } /* Record number of completed objects and recalculate the limit. */ |