sched/mqueue: Make the pre-allocated irq messages configurable

the message can't be dynamically allocated in any irq handler
so it's important to let the user extend the number as needed

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: Ia26584c3815bac6cf24de4c88be0844ac8e8fba2

sched/Kconfig

@@ -1536,6 +1536,12 @@ config PREALLOC_MQ_MSGS
 		The number of pre-allocated message structures.  The system manages
 		a pool of preallocated message structures to minimize dynamic allocations
 
+config PREALLOC_MQ_IRQ_MSGS
+	int "Number of pre-allocated irq messages"
+	default 8
+	---help---
+		The number of pre-allocated irq message structures.
+
 config MQ_MAXMSGSIZE
 	int "Maximum message size"
 	default 32

sched/mqueue/mq_initialize.c

@@ -168,7 +168,7 @@ void nxmq_initialize(void)
    */
 
   g_msgfreeirqalloc =
-    mq_msgblockalloc(&g_msgfreeirq, NUM_INTERRUPT_MSGS,
+    mq_msgblockalloc(&g_msgfreeirq, CONFIG_PREALLOC_MQ_IRQ_MSGS,
                      MQ_ALLOC_IRQ);
 
   /* Allocate a block of message queue descriptors */

sched/mqueue/mqueue.h

@@ -53,12 +53,6 @@
 
 #define NUM_MSG_DESCRIPTORS  4
 
-/* This defines the number of messages to set aside for exclusive use by
- * interrupt handlers
- */
-
-#define NUM_INTERRUPT_MSGS   8
-
 /********************************************************************************
  * Public Type Definitions
  ********************************************************************************/