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

Commit f00b45c1 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched: /debug/sched_features 



provide a text based interface to the scheduler features; this saves the
'user' from setting bits using decimal arithmetic.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 06379aba

kernel/sched.c

+140 −22
Original line number Diff line number Diff line
@@ -68,6 +68,8 @@ 
#include <linux/hrtimer.h>

#include <linux/tick.h>

#include <linux/bootmem.h>

#include <linux/debugfs.h>

#include <linux/ctype.h>



#include <asm/tlb.h>

#include <asm/irq_regs.h>
@@ -732,32 +734,148 @@ static void update_rq_clock(struct rq *rq) 
/*

 * Debugging: various feature bits

 */



#define SCHED_FEAT(name, enabled)	\

	__SCHED_FEAT_##name ,



enum {

	SCHED_FEAT_NEW_FAIR_SLEEPERS	= 1,

	SCHED_FEAT_WAKEUP_PREEMPT	= 2,

	SCHED_FEAT_START_DEBIT		= 4,

	SCHED_FEAT_AFFINE_WAKEUPS	= 8,

	SCHED_FEAT_CACHE_HOT_BUDDY	= 16,

	SCHED_FEAT_SYNC_WAKEUPS		= 32,

	SCHED_FEAT_HRTICK		= 64,

	SCHED_FEAT_DOUBLE_TICK		= 128,

	SCHED_FEAT_NORMALIZED_SLEEPER	= 256,

	SCHED_FEAT_DEADLINE		= 512,

#include "sched_features.h"

};



#undef SCHED_FEAT



#define SCHED_FEAT(name, enabled)	\

	(1UL << __SCHED_FEAT_##name) * enabled |



const_debug unsigned int sysctl_sched_features =

		SCHED_FEAT_NEW_FAIR_SLEEPERS	* 1 |

		SCHED_FEAT_WAKEUP_PREEMPT	* 1 |

		SCHED_FEAT_START_DEBIT		* 1 |

		SCHED_FEAT_AFFINE_WAKEUPS	* 1 |

		SCHED_FEAT_CACHE_HOT_BUDDY	* 1 |

		SCHED_FEAT_SYNC_WAKEUPS		* 1 |

		SCHED_FEAT_HRTICK		* 1 |

		SCHED_FEAT_DOUBLE_TICK		* 0 |

		SCHED_FEAT_NORMALIZED_SLEEPER	* 1 |

		SCHED_FEAT_DEADLINE		* 1;



#define sched_feat(x) (sysctl_sched_features & SCHED_FEAT_##x)

#include "sched_features.h"

	0;



#undef SCHED_FEAT



#ifdef CONFIG_SCHED_DEBUG

#define SCHED_FEAT(name, enabled)	\

	#name ,



__read_mostly char *sched_feat_names[] = {

#include "sched_features.h"

	NULL

};



#undef SCHED_FEAT



int sched_feat_open(struct inode *inode, struct file *filp)

{

	filp->private_data = inode->i_private;

	return 0;

}



static ssize_t

sched_feat_read(struct file *filp, char __user *ubuf,

		size_t cnt, loff_t *ppos)

{

	char *buf;

	int r = 0;

	int len = 0;

	int i;



	for (i = 0; sched_feat_names[i]; i++) {

		len += strlen(sched_feat_names[i]);

		len += 4;

	}



	buf = kmalloc(len + 2, GFP_KERNEL);

	if (!buf)

		return -ENOMEM;



	for (i = 0; sched_feat_names[i]; i++) {

		if (sysctl_sched_features & (1UL << i))

			r += sprintf(buf + r, "%s ", sched_feat_names[i]);

		else

			r += sprintf(buf + r, "no_%s ", sched_feat_names[i]);

	}



	r += sprintf(buf + r, "\n");

	WARN_ON(r >= len + 2);



	r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);



	kfree(buf);



	return r;

}



static ssize_t

sched_feat_write(struct file *filp, const char __user *ubuf,

		size_t cnt, loff_t *ppos)

{

	char buf[64];

	char *cmp = buf;

	int neg = 0;

	int i;



	if (cnt > 63)

		cnt = 63;



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

		return -EFAULT;



	buf[cnt] = 0;



	if (strncmp(buf, "no_", 3) == 0) {

		neg = 1;

		cmp += 3;

	}



	for (i = 0; sched_feat_names[i]; i++) {

		int len = strlen(sched_feat_names[i]);



		if (strncmp(cmp, sched_feat_names[i], len) == 0) {

			if (neg)

				sysctl_sched_features &= ~(1UL << i);

			else

				sysctl_sched_features |= (1UL << i);

			break;

		}

	}



	if (!sched_feat_names[i])

		return -EINVAL;



	filp->f_pos += cnt;



	return cnt;

}



static struct file_operations sched_feat_fops = {

	.open	= sched_feat_open,

	.read	= sched_feat_read,

	.write	= sched_feat_write,

};



static __init int sched_init_debug(void)

{

	int i, j, len;



	for (i = 0; sched_feat_names[i]; i++) {

		len = strlen(sched_feat_names[i]);



		for (j = 0; j < len; j++) {

			sched_feat_names[i][j] =

				tolower(sched_feat_names[i][j]);

		}

	}



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

			&sched_feat_fops);



	return 0;

}

late_initcall(sched_init_debug);



#endif



#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))



/*

 * Number of tasks to iterate in a single balance run.

kernel/sched_features.h

0 → 100644
+10 −0
Original line number Diff line number Diff line 
SCHED_FEAT(NEW_FAIR_SLEEPERS, 1)

SCHED_FEAT(WAKEUP_PREEMPT, 1)

SCHED_FEAT(START_DEBIT, 1)

SCHED_FEAT(AFFINE_WAKEUPS, 1)

SCHED_FEAT(CACHE_HOT_BUDDY, 1)

SCHED_FEAT(SYNC_WAKEUPS, 1)

SCHED_FEAT(HRTICK, 1)

SCHED_FEAT(DOUBLE_TICK, 0)

SCHED_FEAT(NORMALIZED_SLEEPER, 1)

SCHED_FEAT(DEADLINE, 1)