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: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>

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: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Peter Zijlstra · Ingo Molnar
1 parent 06379aba52
Showing 2 changed files with 150 additions and 22 deletions Side-by-side Diff
kernel/sched.c
kernel/sched_features.h
@@ -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 @@
 /*
  * 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;
+#include "sched_features.h"
+	0;
  
-#define sched_feat(x) (sysctl_sched_features & SCHED_FEAT_##x)
+#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.
+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)
...	...	@@ -68,6 +68,8 @@
68	68	#include <linux/hrtimer.h>
69	69	#include <linux/tick.h>
70	70	#include <linux/bootmem.h>
	71	+#include <linux/debugfs.h>
	72	+#include <linux/ctype.h>
71	73
72	74	#include <asm/tlb.h>
73	75	#include <asm/irq_regs.h>
74	76
75	77
76	78
77	79
...	...	@@ -732,32 +734,148 @@
732	734	/*
733	735	* Debugging: various feature bits
734	736	*/
	737	+
	738	+#define SCHED_FEAT(name, enabled) \
	739	+ __SCHED_FEAT_##name ,
	740	+
735	741	enum {
736		- SCHED_FEAT_NEW_FAIR_SLEEPERS = 1,
737		- SCHED_FEAT_WAKEUP_PREEMPT = 2,
738		- SCHED_FEAT_START_DEBIT = 4,
739		- SCHED_FEAT_AFFINE_WAKEUPS = 8,
740		- SCHED_FEAT_CACHE_HOT_BUDDY = 16,
741		- SCHED_FEAT_SYNC_WAKEUPS = 32,
742		- SCHED_FEAT_HRTICK = 64,
743		- SCHED_FEAT_DOUBLE_TICK = 128,
744		- SCHED_FEAT_NORMALIZED_SLEEPER = 256,
745		- SCHED_FEAT_DEADLINE = 512,
	742	+#include "sched_features.h"
746	743	};
747	744
	745	+#undef SCHED_FEAT
	746	+
	747	+#define SCHED_FEAT(name, enabled) \
	748	+ (1UL << __SCHED_FEAT_##name) * enabled \|
	749	+
748	750	const_debug unsigned int sysctl_sched_features =
749		- SCHED_FEAT_NEW_FAIR_SLEEPERS * 1 \|
750		- SCHED_FEAT_WAKEUP_PREEMPT * 1 \|
751		- SCHED_FEAT_START_DEBIT * 1 \|
752		- SCHED_FEAT_AFFINE_WAKEUPS * 1 \|
753		- SCHED_FEAT_CACHE_HOT_BUDDY * 1 \|
754		- SCHED_FEAT_SYNC_WAKEUPS * 1 \|
755		- SCHED_FEAT_HRTICK * 1 \|
756		- SCHED_FEAT_DOUBLE_TICK * 0 \|
757		- SCHED_FEAT_NORMALIZED_SLEEPER * 1 \|
758		- SCHED_FEAT_DEADLINE * 1;
	751	+#include "sched_features.h"
	752	+ 0;
759	753
760		-#define sched_feat(x) (sysctl_sched_features & SCHED_FEAT_##x)
	754	+#undef SCHED_FEAT
	755	+
	756	+#ifdef CONFIG_SCHED_DEBUG
	757	+#define SCHED_FEAT(name, enabled) \
	758	+ #name ,
	759	+
	760	+__read_mostly char *sched_feat_names[] = {
	761	+#include "sched_features.h"
	762	+ NULL
	763	+};
	764	+
	765	+#undef SCHED_FEAT
	766	+
	767	+int sched_feat_open(struct inode inode, struct file filp)
	768	+{
	769	+ filp->private_data = inode->i_private;
	770	+ return 0;
	771	+}
	772	+
	773	+static ssize_t
	774	+sched_feat_read(struct file filp, char __user ubuf,
	775	+ size_t cnt, loff_t *ppos)
	776	+{
	777	+ char *buf;
	778	+ int r = 0;
	779	+ int len = 0;
	780	+ int i;
	781	+
	782	+ for (i = 0; sched_feat_names[i]; i++) {
	783	+ len += strlen(sched_feat_names[i]);
	784	+ len += 4;
	785	+ }
	786	+
	787	+ buf = kmalloc(len + 2, GFP_KERNEL);
	788	+ if (!buf)
	789	+ return -ENOMEM;
	790	+
	791	+ for (i = 0; sched_feat_names[i]; i++) {
	792	+ if (sysctl_sched_features & (1UL << i))
	793	+ r += sprintf(buf + r, "%s ", sched_feat_names[i]);
	794	+ else
	795	+ r += sprintf(buf + r, "no_%s ", sched_feat_names[i]);
	796	+ }
	797	+
	798	+ r += sprintf(buf + r, "\n");
	799	+ WARN_ON(r >= len + 2);
	800	+
	801	+ r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
	802	+
	803	+ kfree(buf);
	804	+
	805	+ return r;
	806	+}
	807	+
	808	+static ssize_t
	809	+sched_feat_write(struct file filp, const char __user ubuf,
	810	+ size_t cnt, loff_t *ppos)
	811	+{
	812	+ char buf[64];
	813	+ char *cmp = buf;
	814	+ int neg = 0;
	815	+ int i;
	816	+
	817	+ if (cnt > 63)
	818	+ cnt = 63;
	819	+
	820	+ if (copy_from_user(&buf, ubuf, cnt))
	821	+ return -EFAULT;
	822	+
	823	+ buf[cnt] = 0;
	824	+
	825	+ if (strncmp(buf, "no_", 3) == 0) {
	826	+ neg = 1;
	827	+ cmp += 3;
	828	+ }
	829	+
	830	+ for (i = 0; sched_feat_names[i]; i++) {
	831	+ int len = strlen(sched_feat_names[i]);
	832	+
	833	+ if (strncmp(cmp, sched_feat_names[i], len) == 0) {
	834	+ if (neg)
	835	+ sysctl_sched_features &= ~(1UL << i);
	836	+ else
	837	+ sysctl_sched_features \|= (1UL << i);
	838	+ break;
	839	+ }
	840	+ }
	841	+
	842	+ if (!sched_feat_names[i])
	843	+ return -EINVAL;
	844	+
	845	+ filp->f_pos += cnt;
	846	+
	847	+ return cnt;
	848	+}
	849	+
	850	+static struct file_operations sched_feat_fops = {
	851	+ .open = sched_feat_open,
	852	+ .read = sched_feat_read,
	853	+ .write = sched_feat_write,
	854	+};
	855	+
	856	+static __init int sched_init_debug(void)
	857	+{
	858	+ int i, j, len;
	859	+
	860	+ for (i = 0; sched_feat_names[i]; i++) {
	861	+ len = strlen(sched_feat_names[i]);
	862	+
	863	+ for (j = 0; j < len; j++) {
	864	+ sched_feat_names[i][j] =
	865	+ tolower(sched_feat_names[i][j]);
	866	+ }
	867	+ }
	868	+
	869	+ debugfs_create_file("sched_features", 0644, NULL, NULL,
	870	+ &sched_feat_fops);
	871	+
	872	+ return 0;
	873	+}
	874	+late_initcall(sched_init_debug);
	875	+
	876	+#endif
	877	+
	878	+#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
761	879
762	880	/*
763	881	* Number of tasks to iterate in a single balance run.
	1	+SCHED_FEAT(NEW_FAIR_SLEEPERS, 1)
	2	+SCHED_FEAT(WAKEUP_PREEMPT, 1)
	3	+SCHED_FEAT(START_DEBIT, 1)
	4	+SCHED_FEAT(AFFINE_WAKEUPS, 1)
	5	+SCHED_FEAT(CACHE_HOT_BUDDY, 1)
	6	+SCHED_FEAT(SYNC_WAKEUPS, 1)
	7	+SCHED_FEAT(HRTICK, 1)
	8	+SCHED_FEAT(DOUBLE_TICK, 0)
	9	+SCHED_FEAT(NORMALIZED_SLEEPER, 1)
	10	+SCHED_FEAT(DEADLINE, 1)