scx_lavd 1.1.0

A Latency-criticality Aware Virtual Deadline (LAVD) scheduler based on sched_ext, which is a Linux kernel feature which enables implementing kernel thread schedulers in BPF and dynamically loading them. https://github.com/sched-ext/scx/tree/main
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152

#include <scx/common.bpf.h>
#include <lib/sdt_task.h>

#include <lib/cpumask.h>
#include <lib/lvqueue.h>

#include "selftest.h"

/*
 * NOTE: These selftests only test for the single-threaded use case, which for
 * Lev-Chase queues is obviously the simplest one. Still, it is important to
 * exercise the API to ensure it passes verification and basic checks.
 */

int scx_selftest_lvqueue_pop_empty(lv_queue_t *lvq)
{
	u64 val;
	int ret;

	ret = lvq_pop(lvq, &val);
	if (ret != -ENOENT)
		return 1;

	return 0;
}

int scx_selftest_lvqueue_steal_empty(lv_queue_t *lvq)
{
	u64 val;
	int ret;

	ret = lvq_steal(lvq, &val);
	if (ret != -ENOENT)
		return 1;

	return 0;
}

int scx_selftest_lvqueue_steal_one(lv_queue_t *lvq)
{
	u64 val, newval;
	int ret, i;

	for (i = 0; i < 10 && can_loop; i++) {
		val = i;

		ret = lvq_push(lvq, val);
		if (ret)
			return 1;

		ret = lvq_steal(lvq, &newval);
		if (ret)
			return 2;

		if (val != newval)
			return 3;
	}

	return 0;
}

int scx_selftest_lvqueue_pop_one(lv_queue_t *lvq)
{
	u64 val, newval;
	int ret, i;

	for (i = 0; i < 10 && can_loop; i++) {
		val = i;

		ret = lvq_push(lvq, val);
		if (ret)
			return 1;

		ret = lvq_pop(lvq, &newval);
		if (ret)
			return 2;

		if (val != newval)
			return 3;
	}

	return 0;
}

int scx_selftest_lvqueue_pop_many(lv_queue_t *lvq)
{
	u64 val, newval;
	int ret, i;

	for (i = 0; i < 10 && can_loop; i++) {
		val = i;

		ret = lvq_push(lvq, val);
		if (ret != -ENOENT)
			return i + 1;
	}

	for (i = 0; i < 2000 && can_loop; i++) {
		ret = lvq_pop(lvq, &newval);
		if (ret != -ENOENT)
			return 2 * i + 2001;

		if (newval != i)
			return 2 * i + 2002;
	}

	return 0;
}


int scx_selftest_lvqueue_steal_many(lv_queue_t *lvq)
{
	u64 val, newval;
	int ret, i;

	for (i = 0; i < 2000 && can_loop; i++) {
		val = i;

		ret = lvq_push(lvq, val);
		if (ret != -ENOENT)
			return i + 1;
	}

	for (i = 0; i < 2000 && can_loop; i++) {
		ret = lvq_steal(lvq, &newval);
		if (ret != -ENOENT)
			return 2 * i + 2001;

		if (newval != 9 - i)
			return 2 * i + 2002;
	}

	return 0;
}

#define SCX_LVQUEUE_SELFTEST(suffix) SCX_SELFTEST(scx_selftest_lvqueue_ ## suffix, lvq)

__weak
int scx_selftest_lvqueue(void)
{
	lv_queue_t *lvq = lvq_create();

	if (!lvq)
		return 1;

	SCX_LVQUEUE_SELFTEST(pop_empty);
	SCX_LVQUEUE_SELFTEST(steal_empty);
	SCX_LVQUEUE_SELFTEST(pop_one);
	SCX_LVQUEUE_SELFTEST(steal_one);

	return 0;
}