Commit 16bf5a5e authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

smp: Rename flush_smp_call_function_from_idle() 



This is invoked from the stopper thread too, which is definitely not idle.
Rename it to flush_smp_call_function_queue() and fixup the callers.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220413133024.305001096@linutronix.de
parent d664e399

kernel/sched/core.c

+1 −1
Original line number Diff line number Diff line
@@ -2411,7 +2411,7 @@ static int migration_cpu_stop(void *data) 
	 * __migrate_task() such that we will not miss enforcing cpus_ptr

	 * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test.

	 */

	flush_smp_call_function_from_idle();

	flush_smp_call_function_queue();



	raw_spin_lock(&p->pi_lock);

	rq_lock(rq, &rf);

kernel/sched/idle.c

+1 −1
Original line number Diff line number Diff line
@@ -327,7 +327,7 @@ static void do_idle(void) 
	 * RCU relies on this call to be done outside of an RCU read-side

	 * critical section.

	 */

	flush_smp_call_function_from_idle();

	flush_smp_call_function_queue();

	schedule_idle();



	if (unlikely(klp_patch_pending(current)))

kernel/sched/smp.h

+2 −2
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ extern void sched_ttwu_pending(void *arg); 
extern void send_call_function_single_ipi(int cpu);



#ifdef CONFIG_SMP

extern void flush_smp_call_function_from_idle(void);

extern void flush_smp_call_function_queue(void);

#else

static inline void flush_smp_call_function_from_idle(void) { }

static inline void flush_smp_call_function_queue(void) { }

#endif

kernel/smp.c

+20 −7
Original line number Diff line number Diff line
@@ -96,7 +96,7 @@ static DEFINE_PER_CPU_ALIGNED(struct call_function_data, cfd_data); 


static DEFINE_PER_CPU_SHARED_ALIGNED(struct llist_head, call_single_queue);



static void flush_smp_call_function_queue(bool warn_cpu_offline);

static void __flush_smp_call_function_queue(bool warn_cpu_offline);



int smpcfd_prepare_cpu(unsigned int cpu)

{
@@ -141,7 +141,7 @@ int smpcfd_dying_cpu(unsigned int cpu) 
	 * ensure that the outgoing CPU doesn't go offline with work

	 * still pending.

	 */

	flush_smp_call_function_queue(false);

	__flush_smp_call_function_queue(false);

	irq_work_run();

	return 0;

}
@@ -541,11 +541,11 @@ void generic_smp_call_function_single_interrupt(void) 
{

	cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->gotipi, CFD_SEQ_NOCPU,

		      smp_processor_id(), CFD_SEQ_GOTIPI);

	flush_smp_call_function_queue(true);

	__flush_smp_call_function_queue(true);

}



/**

 * flush_smp_call_function_queue - Flush pending smp-call-function callbacks

 * __flush_smp_call_function_queue - Flush pending smp-call-function callbacks

 *

 * @warn_cpu_offline: If set to 'true', warn if callbacks were queued on an

 *		      offline CPU. Skip this check if set to 'false'.
@@ -558,7 +558,7 @@ void generic_smp_call_function_single_interrupt(void) 
 * Loop through the call_single_queue and run all the queued callbacks.

 * Must be called with interrupts disabled.

 */

static void flush_smp_call_function_queue(bool warn_cpu_offline)

static void __flush_smp_call_function_queue(bool warn_cpu_offline)

{

	call_single_data_t *csd, *csd_next;

	struct llist_node *entry, *prev;
@@ -681,7 +681,20 @@ static void flush_smp_call_function_queue(bool warn_cpu_offline) 
		      smp_processor_id(), CFD_SEQ_HDLEND);

}



void flush_smp_call_function_from_idle(void)



/**

 * flush_smp_call_function_queue - Flush pending smp-call-function callbacks

 *				   from task context (idle, migration thread)

 *

 * When TIF_POLLING_NRFLAG is supported and a CPU is in idle and has it

 * set, then remote CPUs can avoid sending IPIs and wake the idle CPU by

 * setting TIF_NEED_RESCHED. The idle task on the woken up CPU has to

 * handle queued SMP function calls before scheduling.

 *

 * The migration thread has to ensure that an eventually pending wakeup has

 * been handled before it migrates a task.

 */

void flush_smp_call_function_queue(void)

{

	unsigned long flags;
@@ -691,7 +704,7 @@ void flush_smp_call_function_from_idle(void) 
	cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->idle, CFD_SEQ_NOCPU,

		      smp_processor_id(), CFD_SEQ_IDLE);

	local_irq_save(flags);

	flush_smp_call_function_queue(true);

	__flush_smp_call_function_queue(true);

	if (local_softirq_pending())

		do_softirq();