Document workqueue configuration

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2231 42af7a65-404d-4744-a932-0658087f49c3

3 files changed, 52 insertions, 2 deletions

diff --git a/nuttx/Documentation/NuttxPortingGuide.html b/nuttx/Documentation/NuttxPortingGuide.html
index dec31beea..c3093d8b7 100644
--- a/nuttx/Documentation/NuttxPortingGuide.html
+++ b/nuttx/Documentation/NuttxPortingGuide.html
@@ -12,7 +12,7 @@
       <h1><big><font color="#3c34ec">
         <i>NuttX RTOS Porting Guide</i>
       </font></big></h1>
-      <p>Last Updated: September 15, 2009</p>
+      <p>Last Updated: November 5, 2009</p>
     </td>
   </tr>
 </table>
@@ -2124,12 +2124,40 @@ extern void up_ledoff(int led);
     <code>CONFIG_SDCLONE_DISABLE</code>: Disable cloning of all socket
     desciptors by task_create() when a new task is started.
     If set, all sockets will appear to be closed in the new task.
-  </li>: 
+  </li>
   <li>
     <code>CONFIG_NXFLAT</code>: Enable support for the NXFLAT binary format.
     This format will support execution of NuttX binaries located
     in a ROMFS filesystem (see <code>examples/nxflat</code>).
   </li>
+  <li>
+    <code>CONFIG_SCHED_WORKQUEUE</code>: Create a dedicated "worker" thread to
+    handle delayed processing from interrupt handlers.  This feature
+    is required for some drivers but, if there are not complaints,
+    can be safely disabled.  The worker thread also performs
+    garbage collection -- completing any delayed memory deallocations
+    from interrupt handlers.  If the worker thread is disabled,
+    then that clean will be performed by the IDLE thread instead
+    (which runs at the lowest of priority and may not be appropriate
+    if memory reclamation is of high priority).  If CONFIG_SCHED_WORKQUEUE
+    is enabled, then the following options can also be used:
+  </li>
+  <li>
+    <code>CONFIG_SCHED_WORKPRIORITY</code>: The execution priority of the worker
+    thread.  Default: 50
+  </li>
+  <li>
+    <code>CONFIG_SCHED_WORKPERIOD</code>: How often the worker thread checks for
+    work.  Default: 50 MS.
+  </li>
+  <li>
+    <code>CONFIG_SCHED_WORKSTACKSIZE</code>: The stack size allocated for the worker
+    thread.  Default: CONFIG_IDLETHREAD_STACKSIZE.
+  </li>
+  <li>
+    <code>CONFIG_SIG_SIGWORK</code>: The signal number that will be used to wake-up
+    the worker thread.  Default: 4
+  </li>
 </ul>
 
 <p>
diff --git a/nuttx/configs/README.txt b/nuttx/configs/README.txt
index 80cd358c5..eb1a2878e 100644
--- a/nuttx/configs/README.txt
+++ b/nuttx/configs/README.txt
@@ -243,6 +243,24 @@ defconfig -- This is a configuration file similar to the Linux
 		CONFIG_NXFLAT. Enable support for the NXFLAT binary format.
 		  This format will support execution of NuttX binaries located
 		  in a ROMFS filesystem (see examples/nxflat).
+		CONFIG_SCHED_WORKQUEUE.  Create a dedicated "worker" thread to
+		  handle delayed processing from interrupt handlers.  This feature
+		  is required for some drivers but, if there are not complaints,
+		  can be safely disabled.  The worker thread also performs
+		  garbage collection -- completing any delayed memory deallocations
+		  from interrupt handlers.  If the worker thread is disabled,
+		  then that clean will be performed by the IDLE thread instead
+		  (which runs at the lowest of priority and may not be appropriate
+		  if memory reclamation is of high priority).  If CONFIG_SCHED_WORKQUEUE
+		  is enabled, then the following options can also be used:
+		CONFIG_SCHED_WORKPRIORITY - The execution priority of the worker
+		  thread.  Default: 50
+		CONFIG_SCHED_WORKPERIOD - How often the worker thread checks for
+		  work.  Default: 50 MS.
+		CONFIG_SCHED_WORKSTACKSIZE - The stack size allocated for the worker
+		  thread.  Default: CONFIG_IDLETHREAD_STACKSIZE.
+		CONFIG_SIG_SIGWORK - The signal number that will be used to wake-up
+		  the worker thread.  Default: 4
 
 	The following can be used to disable categories of APIs supported
 	by the OS.  If the compiler supports weak functions, then it
diff --git a/nuttx/sched/work_internal.h b/nuttx/sched/work_internal.h
index 93ad57271..90f9e4ba1 100755
--- a/nuttx/sched/work_internal.h
+++ b/nuttx/sched/work_internal.h
@@ -64,6 +64,10 @@
 #  define CONFIG_SCHED_WORKSTACKSIZE CONFIG_IDLETHREAD_STACKSIZE
 #endif
 
+#ifdef CONFIG_DISABLE_SIGNALS
+#  warning "Worker thread support requires signals"
+#endif
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/