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authorTakashi Iwai <tiwai@suse.de>2014-10-22 12:19:57 +0200
committerTakashi Iwai <tiwai@suse.de>2014-10-22 12:19:57 +0200
commit930352862e9533fecc42c7ed20798a7c9e3aa874 (patch)
treef234d6eb69c077f898e375aef30c9550dcf069d7 /include/linux/dynamic_queue_limits.h
parentMerge branch 'topic/hda-lo-jack' into for-next (diff)
parentALSA: usb-audio: Use snd_ctl_enum_info() (diff)
Merge branch 'topic/enum-info-cleanup' into for-next
this is a series of patches to just convert the plain info callback for enum ctl elements to snd_ctl_elem_info(). Also, it includes the extension of snd_ctl_elem_info(), for catching the unexpected string cut-off and handling the zero items.
Diffstat (limited to 'include/linux/dynamic_queue_limits.h')
-rw-r--r--include/linux/dynamic_queue_limits.h12
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. */