2 files changed, 18 insertions, 9 deletions

diff --git a/arch/tile/include/asm/switch_to.h b/arch/tile/include/asm/switch_to.h
index b8f888cbe6b0..422842a56a3d 100644
--- a/arch/tile/include/asm/switch_to.h
+++ b/arch/tile/include/asm/switch_to.h
@@ -53,15 +53,11 @@ extern unsigned long get_switch_to_pc(void);
  * Kernel threads can check to see if they need to migrate their
  * stack whenever they return from a context switch; for user
  * threads, we defer until they are returning to user-space.
+ * We defer homecache migration until the runqueue lock is released.
  */
-#define finish_arch_switch(prev) do {                                     \
-        if (unlikely((prev)->state == TASK_DEAD))                         \
-                __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_EXIT |       \
-                        ((prev)->pid << _SIM_CONTROL_OPERATOR_BITS));     \
-        __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_SWITCH |             \
-                (current->pid << _SIM_CONTROL_OPERATOR_BITS));            \
+#define finish_arch_post_lock_switch() do {                               \
         if (current->mm == NULL && !kstack_hash &&                        \
-            current_thread_info()->homecache_cpu != smp_processor_id())   \
+            current_thread_info()->homecache_cpu != raw_smp_processor_id()) \
                 homecache_migrate_kthread();                              \
 } while (0)
 
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index a45213781ad0..1087375cd57c 100644
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -448,11 +448,24 @@ struct task_struct *__sched _switch_to(struct task_struct *prev,
 
         /*
          * Switch kernel SP, PC, and callee-saved registers.
+         * Pass the value to use for SYSTEM_SAVE_K_0 when we reset our sp.
+         * Once we return from this function we will have changed stacks
+         * and be running with current == next.
+         */
+        __switch_to(prev, next, next_current_ksp0(next));
+
+        /* Notify the simulator of task switch and task exit. */
+        if (unlikely(prev->state == TASK_DEAD))
+                __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_EXIT |
+                             (prev->pid << _SIM_CONTROL_OPERATOR_BITS));
+        __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_SWITCH |
+                (next->pid << _SIM_CONTROL_OPERATOR_BITS));
+
+        /*
          * In the context of the new task, return the old task pointer
          * (i.e. the task that actually called __switch_to).
-         * Pass the value to use for SYSTEM_SAVE_K_0 when we reset our sp.
          */
-        return __switch_to(prev, next, next_current_ksp0(next));
+        return prev;
 }
 
 /*