sched, tile: Remove finish_arch_switch

Move the simulator bits into switch_to() and use
finish_arch_post_lock_switch() for the homecache migration bits.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/tile/include/asm/switch_to.h b/arch/tile/include/asm/switch_to.h
index b8f888c..422842a 100644 (file)
--- 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 a452137..1087375 100644 (file)
--- 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;
 }
 
 /*