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yaml --- r: 10989 b: refs/heads/master c: 57f0060 h: refs/heads/master i: 10987: deec589 v: v3
git-mirror · Oct 29, 2005 · d920d8c · d920d8c
1 parent 8840ec8
commit d920d8c
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Showing 2 changed files with 14 additions and 2 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 26852d5cdb2bac01f2a48b815194a045e8a8e300
+refs/heads/master: 57f0060b8a2bb2a70a4cce1a37d5e0158cea92a6
diff --git a/trunk/arch/mips/kernel/smp.c b/trunk/arch/mips/kernel/smp.c
@@ -121,7 +121,19 @@ struct call_data_struct *call_data;
  * or are or have executed.
  *
  * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler or from a bottom half handler.
+ * hardware interrupt handler or from a bottom half handler:
+ *
+ * CPU A                               CPU B
+ * Disable interrupts
+ *                                     smp_call_function()
+ *                                     Take call_lock
+ *                                     Send IPIs
+ *                                     Wait for all cpus to acknowledge IPI
+ *                                     CPU A has not responded, spin waiting
+ *                                     for cpu A to respond, holding call_lock
+ * smp_call_function()
+ * Spin waiting for call_lock
+ * Deadlock                            Deadlock
  */
 int smp_call_function (void (*func) (void *info), void *info, int retry,
 								int wait)