From: Chris Metcalf <[email protected]> Move the simulator bits into switch_to() and use finish_arch_post_lock_switch() for the homecache migration bits.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]> --- arch/tile/include/asm/switch_to.h | 10 +++------- arch/tile/kernel/process.c | 17 +++++++++++++++-- 2 files changed, 18 insertions(+), 9 deletions(-) --- 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(vo * 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) --- a/arch/tile/kernel/process.c +++ b/arch/tile/kernel/process.c @@ -448,11 +448,24 @@ struct task_struct *__sched _switch_to(s /* * 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; } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
