hc
2023-12-11 d2ccde1c8e90d38cee87a1b0309ad2827f3fd30d
kernel/kernel/trace/preemptirq_delay_test.c
....@@ -10,18 +10,28 @@
1010 #include <linux/interrupt.h>
1111 #include <linux/irq.h>
1212 #include <linux/kernel.h>
13
+#include <linux/kobject.h>
1314 #include <linux/kthread.h>
1415 #include <linux/module.h>
1516 #include <linux/printk.h>
1617 #include <linux/string.h>
18
+#include <linux/sysfs.h>
19
+#include <linux/completion.h>
1720
1821 static ulong delay = 100;
19
-static char test_mode[10] = "irq";
22
+static char test_mode[12] = "irq";
23
+static uint burst_size = 1;
2024
21
-module_param_named(delay, delay, ulong, S_IRUGO);
22
-module_param_string(test_mode, test_mode, 10, S_IRUGO);
23
-MODULE_PARM_DESC(delay, "Period in microseconds (100 uS default)");
24
-MODULE_PARM_DESC(test_mode, "Mode of the test such as preempt or irq (default irq)");
25
+module_param_named(delay, delay, ulong, 0444);
26
+module_param_string(test_mode, test_mode, 12, 0444);
27
+module_param_named(burst_size, burst_size, uint, 0444);
28
+MODULE_PARM_DESC(delay, "Period in microseconds (100 us default)");
29
+MODULE_PARM_DESC(test_mode, "Mode of the test such as preempt, irq, or alternate (default irq)");
30
+MODULE_PARM_DESC(burst_size, "The size of a burst (default 1)");
31
+
32
+static struct completion done;
33
+
34
+#define MIN(x, y) ((x) < (y) ? (x) : (y))
2535
2636 static void busy_wait(ulong time)
2737 {
....@@ -34,37 +44,159 @@
3444 } while ((end - start) < (time * 1000));
3545 }
3646
37
-static int preemptirq_delay_run(void *data)
47
+static __always_inline void irqoff_test(void)
3848 {
3949 unsigned long flags;
50
+ local_irq_save(flags);
51
+ busy_wait(delay);
52
+ local_irq_restore(flags);
53
+}
4054
41
- if (!strcmp(test_mode, "irq")) {
42
- local_irq_save(flags);
43
- busy_wait(delay);
44
- local_irq_restore(flags);
45
- } else if (!strcmp(test_mode, "preempt")) {
46
- preempt_disable();
47
- busy_wait(delay);
48
- preempt_enable();
55
+static __always_inline void preemptoff_test(void)
56
+{
57
+ preempt_disable();
58
+ busy_wait(delay);
59
+ preempt_enable();
60
+}
61
+
62
+static void execute_preemptirqtest(int idx)
63
+{
64
+ if (!strcmp(test_mode, "irq"))
65
+ irqoff_test();
66
+ else if (!strcmp(test_mode, "preempt"))
67
+ preemptoff_test();
68
+ else if (!strcmp(test_mode, "alternate")) {
69
+ if (idx % 2 == 0)
70
+ irqoff_test();
71
+ else
72
+ preemptoff_test();
4973 }
74
+}
75
+
76
+#define DECLARE_TESTFN(POSTFIX) \
77
+ static void preemptirqtest_##POSTFIX(int idx) \
78
+ { \
79
+ execute_preemptirqtest(idx); \
80
+ } \
81
+
82
+/*
83
+ * We create 10 different functions, so that we can get 10 different
84
+ * backtraces.
85
+ */
86
+DECLARE_TESTFN(0)
87
+DECLARE_TESTFN(1)
88
+DECLARE_TESTFN(2)
89
+DECLARE_TESTFN(3)
90
+DECLARE_TESTFN(4)
91
+DECLARE_TESTFN(5)
92
+DECLARE_TESTFN(6)
93
+DECLARE_TESTFN(7)
94
+DECLARE_TESTFN(8)
95
+DECLARE_TESTFN(9)
96
+
97
+static void (*testfuncs[])(int) = {
98
+ preemptirqtest_0,
99
+ preemptirqtest_1,
100
+ preemptirqtest_2,
101
+ preemptirqtest_3,
102
+ preemptirqtest_4,
103
+ preemptirqtest_5,
104
+ preemptirqtest_6,
105
+ preemptirqtest_7,
106
+ preemptirqtest_8,
107
+ preemptirqtest_9,
108
+};
109
+
110
+#define NR_TEST_FUNCS ARRAY_SIZE(testfuncs)
111
+
112
+static int preemptirq_delay_run(void *data)
113
+{
114
+ int i;
115
+ int s = MIN(burst_size, NR_TEST_FUNCS);
116
+
117
+ for (i = 0; i < s; i++)
118
+ (testfuncs[i])(i);
119
+
120
+ complete(&done);
121
+
122
+ set_current_state(TASK_INTERRUPTIBLE);
123
+ while (!kthread_should_stop()) {
124
+ schedule();
125
+ set_current_state(TASK_INTERRUPTIBLE);
126
+ }
127
+
128
+ __set_current_state(TASK_RUNNING);
50129
51130 return 0;
52131 }
53132
54
-static int __init preemptirq_delay_init(void)
133
+static int preemptirq_run_test(void)
55134 {
135
+ struct task_struct *task;
56136 char task_name[50];
57
- struct task_struct *test_task;
137
+
138
+ init_completion(&done);
58139
59140 snprintf(task_name, sizeof(task_name), "%s_test", test_mode);
141
+ task = kthread_run(preemptirq_delay_run, NULL, task_name);
142
+ if (IS_ERR(task))
143
+ return PTR_ERR(task);
144
+ if (task) {
145
+ wait_for_completion(&done);
146
+ kthread_stop(task);
147
+ }
148
+ return 0;
149
+}
60150
61
- test_task = kthread_run(preemptirq_delay_run, NULL, task_name);
62
- return PTR_ERR_OR_ZERO(test_task);
151
+
152
+static ssize_t trigger_store(struct kobject *kobj, struct kobj_attribute *attr,
153
+ const char *buf, size_t count)
154
+{
155
+ ssize_t ret;
156
+
157
+ ret = preemptirq_run_test();
158
+ if (ret)
159
+ return ret;
160
+ return count;
161
+}
162
+
163
+static struct kobj_attribute trigger_attribute =
164
+ __ATTR(trigger, 0200, NULL, trigger_store);
165
+
166
+static struct attribute *attrs[] = {
167
+ &trigger_attribute.attr,
168
+ NULL,
169
+};
170
+
171
+static struct attribute_group attr_group = {
172
+ .attrs = attrs,
173
+};
174
+
175
+static struct kobject *preemptirq_delay_kobj;
176
+
177
+static int __init preemptirq_delay_init(void)
178
+{
179
+ int retval;
180
+
181
+ retval = preemptirq_run_test();
182
+ if (retval != 0)
183
+ return retval;
184
+
185
+ preemptirq_delay_kobj = kobject_create_and_add("preemptirq_delay_test",
186
+ kernel_kobj);
187
+ if (!preemptirq_delay_kobj)
188
+ return -ENOMEM;
189
+
190
+ retval = sysfs_create_group(preemptirq_delay_kobj, &attr_group);
191
+ if (retval)
192
+ kobject_put(preemptirq_delay_kobj);
193
+
194
+ return retval;
63195 }
64196
65197 static void __exit preemptirq_delay_exit(void)
66198 {
67
- return;
199
+ kobject_put(preemptirq_delay_kobj);
68200 }
69201
70202 module_init(preemptirq_delay_init)