net: dql: Separate queue function responsibilities

The dql_queued() function currently handles both queuing object counts
and populating bitmaps for reporting stalls.

This commit splits the bitmap population into a separate function,
allowing for conditional invocation in scenarios where the feature is
disabled.

This refactor maintains functionality while improving code
organization.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240411192241.2498631-3-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/linux/dynamic_queue_limits.h b/include/linux/dynamic_queue_limits.h
index ff9c65841ae8d7b435d1d7aed177f8e8be154169..9980df0b7247278a8eb4d592286259e8fe8059c8 100644 (file)
--- a/include/linux/dynamic_queue_limits.h
+++ b/include/linux/dynamic_queue_limits.h
@@ -83,28 +83,11 @@ struct dql {
 #define DQL_MAX_OBJECT (UINT_MAX / 16)
 #define DQL_MAX_LIMIT ((UINT_MAX / 2) - DQL_MAX_OBJECT)
 
-/*
- * Record number of objects queued. Assumes that caller has already checked
- * availability in the queue with dql_avail.
- */
-static inline void dql_queued(struct dql *dql, unsigned int count)
+/* Populate the bitmap to be processed later in dql_check_stall() */
+static inline void dql_queue_stall(struct dql *dql)
 {
        unsigned long map, now, now_hi, i;
 
-       if (WARN_ON_ONCE(count > DQL_MAX_OBJECT))
-               return;
-
-       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;
-
        now = jiffies;
        now_hi = now / BITS_PER_LONG;
 
@@ -134,6 +117,29 @@ static inline void dql_queued(struct dql *dql, unsigned int count)
                WRITE_ONCE(DQL_HIST_ENT(dql, now_hi), map | BIT_MASK(now));
 }
 
+/*
+ * Record number of objects queued. Assumes that caller has already checked
+ * availability in the queue with dql_avail.
+ */
+static inline void dql_queued(struct dql *dql, unsigned int count)
+{
+       if (WARN_ON_ONCE(count > DQL_MAX_OBJECT))
+               return;
+
+       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;
+
+       dql_queue_stall(dql);
+}
+
 /* Returns how many objects can be queued, < 0 indicates over limit. */
 static inline int dql_avail(const struct dql *dql)
 {