Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 2ee507c4 authored by Tim Chen's avatar Tim Chen Committed by Herbert Xu
Browse files

sched: Add function single_task_running to let a task check if it is the only task running on a cpu 



This function will help an async task processing batched jobs from
workqueue decide if it wants to keep processing on more chunks of batched
work that can be delayed, or to accumulate more work for more efficient
batched processing later.

If no other tasks are running on the cpu, the batching process can take
advantgae of the available cpu cycles to a make decision to continue
processing the existing accumulated work to minimize delay,
otherwise it will yield.

Signed-off-by: default avatarTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent bbb9a7dd

include/linux/sched.h

+1 −0
Original line number Diff line number Diff line
@@ -167,6 +167,7 @@ extern int nr_threads; 
DECLARE_PER_CPU(unsigned long, process_counts);

extern int nr_processes(void);

extern unsigned long nr_running(void);

extern bool single_task_running(void);

extern unsigned long nr_iowait(void);

extern unsigned long nr_iowait_cpu(int cpu);

extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);

kernel/sched/core.c

+12 −0
Original line number Diff line number Diff line
@@ -2366,6 +2366,18 @@ unsigned long nr_running(void) 
	return sum;

}



/*

 * Check if only the current task is running on the cpu.

 */

bool single_task_running(void)

{

	if (cpu_rq(smp_processor_id())->nr_running == 1)

		return true;

	else

		return false;

}

EXPORT_SYMBOL(single_task_running);



unsigned long long nr_context_switches(void)

{

	int i;