From fe363adb922583bacfbd5a30a4c773ccff9bb393 Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Wed, 29 Jul 2015 13:06:29 -0400 Subject: [PATCH] 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 Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- 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 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; } /*