Commit 8a99b683 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

sched: Move SCHED_DEBUG sysctl to debugfs 



Stop polluting sysctl with undocumented knobs that really are debug
only, move them all to /debug/sched/ along with the existing
/debug/sched_* files that already exist.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: default avatarValentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210412102001.287610138@infradead.org
parent d86ba831

include/linux/sched/sysctl.h

+3 −5
Original line number Diff line number Diff line
@@ -26,10 +26,11 @@ int proc_dohung_task_timeout_secs(struct ctl_table *table, int write, 
enum { sysctl_hung_task_timeout_secs = 0 };

#endif



extern unsigned int sysctl_sched_child_runs_first;



extern unsigned int sysctl_sched_latency;

extern unsigned int sysctl_sched_min_granularity;

extern unsigned int sysctl_sched_wakeup_granularity;

extern unsigned int sysctl_sched_child_runs_first;



enum sched_tunable_scaling {

	SCHED_TUNABLESCALING_NONE,
@@ -37,7 +38,7 @@ enum sched_tunable_scaling { 
	SCHED_TUNABLESCALING_LINEAR,

	SCHED_TUNABLESCALING_END,

};

extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;

extern unsigned int sysctl_sched_tunable_scaling;



extern unsigned int sysctl_numa_balancing_scan_delay;

extern unsigned int sysctl_numa_balancing_scan_period_min;
@@ -47,9 +48,6 @@ extern unsigned int sysctl_numa_balancing_scan_size; 
#ifdef CONFIG_SCHED_DEBUG

extern __read_mostly unsigned int sysctl_sched_migration_cost;

extern __read_mostly unsigned int sysctl_sched_nr_migrate;



int sched_proc_update_handler(struct ctl_table *table, int write,

		void *buffer, size_t *length, loff_t *ppos);

#endif



/*

kernel/sched/core.c

+3 −1
Original line number Diff line number Diff line
@@ -5504,9 +5504,11 @@ static const struct file_operations sched_dynamic_fops = { 
	.release	= single_release,

};



extern struct dentry *debugfs_sched;



static __init int sched_init_debug_dynamic(void)

{

	debugfs_create_file("sched_preempt", 0644, NULL, NULL, &sched_dynamic_fops);

	debugfs_create_file("sched_preempt", 0644, debugfs_sched, NULL, &sched_dynamic_fops);

	return 0;

}

late_initcall(sched_init_debug_dynamic);

kernel/sched/debug.c

+70 −4
Original line number Diff line number Diff line
@@ -169,15 +169,81 @@ static const struct file_operations sched_feat_fops = { 
	.release	= single_release,

};



#ifdef CONFIG_SMP



static ssize_t sched_scaling_write(struct file *filp, const char __user *ubuf,

				   size_t cnt, loff_t *ppos)

{

	char buf[16];



	if (cnt > 15)

		cnt = 15;



	if (copy_from_user(&buf, ubuf, cnt))

		return -EFAULT;



	if (kstrtouint(buf, 10, &sysctl_sched_tunable_scaling))

		return -EINVAL;



	if (sched_update_scaling())

		return -EINVAL;



	*ppos += cnt;

	return cnt;

}



static int sched_scaling_show(struct seq_file *m, void *v)

{

	seq_printf(m, "%d\n", sysctl_sched_tunable_scaling);

	return 0;

}



static int sched_scaling_open(struct inode *inode, struct file *filp)

{

	return single_open(filp, sched_scaling_show, NULL);

}



static const struct file_operations sched_scaling_fops = {

	.open		= sched_scaling_open,

	.write		= sched_scaling_write,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= single_release,

};



#endif /* SMP */



__read_mostly bool sched_debug_enabled;



struct dentry *debugfs_sched;



static __init int sched_init_debug(void)

{

	debugfs_create_file("sched_features", 0644, NULL, NULL,

			&sched_feat_fops);

	struct dentry __maybe_unused *numa;



	debugfs_create_bool("sched_debug", 0644, NULL,

			&sched_debug_enabled);

	debugfs_sched = debugfs_create_dir("sched", NULL);



	debugfs_create_file("features", 0644, debugfs_sched, NULL, &sched_feat_fops);

	debugfs_create_bool("debug_enabled", 0644, debugfs_sched, &sched_debug_enabled);



	debugfs_create_u32("latency_ns", 0644, debugfs_sched, &sysctl_sched_latency);

	debugfs_create_u32("min_granularity_ns", 0644, debugfs_sched, &sysctl_sched_min_granularity);

	debugfs_create_u32("wakeup_granularity_ns", 0644, debugfs_sched, &sysctl_sched_wakeup_granularity);



#ifdef CONFIG_SMP

	debugfs_create_file("tunable_scaling", 0644, debugfs_sched, NULL, &sched_scaling_fops);

	debugfs_create_u32("migration_cost_ns", 0644, debugfs_sched, &sysctl_sched_migration_cost);

	debugfs_create_u32("nr_migrate", 0644, debugfs_sched, &sysctl_sched_nr_migrate);

#endif



#ifdef CONFIG_NUMA_BALANCING

	numa = debugfs_create_dir("numa_balancing", debugfs_sched);



	debugfs_create_u32("scan_delay_ms", 0644, numa, &sysctl_numa_balancing_scan_delay);

	debugfs_create_u32("scan_period_min_ms", 0644, numa, &sysctl_numa_balancing_scan_period_min);

	debugfs_create_u32("scan_period_max_ms", 0644, numa, &sysctl_numa_balancing_scan_period_max);

	debugfs_create_u32("scan_size_mb", 0644, numa, &sysctl_numa_balancing_scan_size);

#endif



	return 0;

}

kernel/sched/fair.c

+2 −7
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ static unsigned int normalized_sysctl_sched_latency = 6000000ULL; 
 *

 * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))

 */

enum sched_tunable_scaling sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_LOG;

unsigned int sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_LOG;



/*

 * Minimal preemption granularity for CPU-bound tasks:
@@ -634,15 +634,10 @@ struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) 
 * Scheduling class statistics methods:

 */



int sched_proc_update_handler(struct ctl_table *table, int write,

		void *buffer, size_t *lenp, loff_t *ppos)

int sched_update_scaling(void)

{

	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);

	unsigned int factor = get_update_sysctl_factor();



	if (ret || !write)

		return ret;



	sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency,

					sysctl_sched_min_granularity);

kernel/sched/sched.h

+2 −0
Original line number Diff line number Diff line
@@ -1568,6 +1568,8 @@ static inline void unregister_sched_domain_sysctl(void) 
}

#endif



extern int sched_update_scaling(void);



extern void flush_smp_call_function_from_idle(void);



#else /* !CONFIG_SMP: */