Re: [tip:sched/core] sched, tile: Remove finish_arch_switch
From: Chris Metcalf
Date: Tue Aug 04 2015 - 09:46:55 EST
Ingo,
I already have the appended commit in a modified form in the linux-tile
tree ready to be pushed to 4.3. Can you drop it from your series?
Thanks!
On 8/4/2015 4:50 AM, tip-bot for Chris Metcalf wrote:
Commit-ID: fe363adb922583bacfbd5a30a4c773ccff9bb393
Gitweb: http://git.kernel.org/tip/fe363adb922583bacfbd5a30a4c773ccff9bb393
Author: Chris Metcalf <cmetcalf@xxxxxxxxxx>
AuthorDate: Wed, 29 Jul 2015 13:06:29 -0400
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 4 Aug 2015 09:38:18 +0200
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@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/tile/include/asm/switch_to.h | 10 +++-------
arch/tile/kernel/process.c | 17 +++++++++++++++--
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 b8f888c..422842a 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 a452137..1087375 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;
}
/*
--
Chris Metcalf, EZChip Semiconductor
http://www.ezchip.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/