From ddbc94889509be9a9dfdb422f2da4bfd2f122834 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Thu, 11 Feb 2016 12:18:54 -0600
Subject: [PATCH] SMP: Minor SMP-related clean-up/improvements

---
 arch                     |  2 +-
 configs                  |  2 +-
 sched/Kconfig            |  9 +++++++++
 sched/init/os_smpstart.c | 21 ++-------------------
 sched/init/os_start.c    | 18 ++++++------------
 5 files changed, 19 insertions(+), 33 deletions(-)

diff --git a/arch b/arch
index 7451a16948..cf3c8382fa 160000
--- a/arch
+++ b/arch
@@ -1 +1 @@
-Subproject commit 7451a16948db82ad2a75723df73160357d816577
+Subproject commit cf3c8382fa36d28b1f153536368cfb07adfbb286
diff --git a/configs b/configs
index 81a10b64ed..600d77e8b4 160000
--- a/configs
+++ b/configs
@@ -1 +1 @@
-Subproject commit 81a10b64ed544684bb975e218e09ab5bc8aaf445
+Subproject commit 600d77e8b4631a67a6099b35a6959b6099b4a42b
diff --git a/sched/Kconfig b/sched/Kconfig
index 5a31c6727d..c30b672b1d 100644
--- a/sched/Kconfig
+++ b/sched/Kconfig
@@ -256,6 +256,15 @@ config SMP_NCPUS
 		This value identifies the number of CPUs support by the processor
 		that will be used for SMP.
 
+config SMP_IDLETHREAD_STACKSIZE
+	int "CPU IDLE stack size"
+	default 2048
+	---help---
+		Each CPU will have its own IDLE stack.  System initialization occurs
+		on CPU0 and uses CONFIG_IDLETHREAD_STACKSIZE which will probably be
+		larger than is generally needed.  This setting provides the STACK
+		size for the IDLE task on CPUS 1 through (CONFIG_SMP_NCPUS-1).
+
 endif # SMP
 
 choice
diff --git a/sched/init/os_smpstart.c b/sched/init/os_smpstart.c
index bfbc49d509..351e90324a 100644
--- a/sched/init/os_smpstart.c
+++ b/sched/init/os_smpstart.c
@@ -40,14 +40,12 @@
 #include <nuttx/config.h>
 
 #include <sys/types.h>
-#include <sched.h>
 #include <debug.h>
 
 #include <nuttx/arch.h>
 #include <nuttx/kmalloc.h>
 
-# include "sched/sched.h"
-# include "init/init.h"
+#include "init/init.h"
 
 #ifdef CONFIG_SMP
 
@@ -72,22 +70,7 @@
 
 int os_idletask(int argc, FAR char *argv[])
 {
-  FAR struct tcb_s *rtcb = this_task();
-  irqstate_t flags;
-  int cpu = this_cpu();
-
-  /* Make sure that this thread is assigned to the current CPU */
-
-  DEBUGASSERT(rtcb->cpu == cpu);
-
-  /* REVISIT: disabling interrupts is not sufficient protection */
-
-  flags        = irqsave();
-  rtcb->flags |= TCB_FLAG_CPU_ASSIGNED;
-  rtcb->cpu    = cpu;
-  irqrestore(flags);
-
-  /* Then enter the IDLE loop */
+  /* Enter the IDLE loop */
 
   sdbg("CPU%d: Beginning Idle Loop\n");
   for (; ; )
diff --git a/sched/init/os_start.c b/sched/init/os_start.c
index 95fd9526c9..c0caabc8f7 100644
--- a/sched/init/os_start.c
+++ b/sched/init/os_start.c
@@ -300,20 +300,16 @@ uint8_t g_os_initstate;  /* See enum os_initstate_e */
  * initialization task is responsible for bringing up the rest of the system.
  */
 
-static FAR struct task_tcb_s g_idletcb;
+static struct task_tcb_s g_idletcb;
 
 /* This is the name of the idle task */
 
-static FAR const char g_idlename[] = "Idle Task";
+static const char g_idlename[] = "Idle Task";
 
 /* This the IDLE idle threads argument list. */
 
 static FAR char *g_idleargv[2];
 
-/****************************************************************************
- * Private Function Prototypes
- ****************************************************************************/
-
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -336,6 +332,7 @@ static FAR char *g_idleargv[2];
 
 void os_start(void)
 {
+  FAR dq_queue_t *tasklist;
   int i;
 
   slldbg("Entry\n");
@@ -438,14 +435,11 @@ void os_start(void)
   /* Then add the idle task's TCB to the head of the ready to run list */
 
 #ifdef CONFIG_SMP
-  /* Use the list a ready-to-run tasks assigned to CPU0 */
-
-  dq_addfirst((FAR dq_entry_t *)&g_idletcb, (FAR dq_queue_t *)&g_assignedtasks[0]);
+  tasklist = TLIST_HEAD(TSTATE_TASK_RUNNING, 0);
 #else
-  /* Use the common, unassigned ready-to-run list */
-
-  dq_addfirst((FAR dq_entry_t *)&g_idletcb, (FAR dq_queue_t *)&g_readytorun);
+  tasklist = TLIST_HEAD(TSTATE_TASK_RUNNING);
 #endif
+  dq_addfirst((FAR dq_entry_t *)&g_idletcb, tasklist);
 
   /* Initialize the processor-specific portion of the TCB */