aboutsummaryrefslogtreecommitdiff
path: root/kernel/rcupreempt_trace.c
blob: 11640346a50727a4b64975e9d0950d5edb5ddc81 (plain)
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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
/*
 * Read-Copy Update tracing for realtime implementation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright IBM Corporation, 2006
 *
 * Papers:  http://www.rdrop.com/users/paulmck/RCU
 *
 * For detailed explanation of Read-Copy Update mechanism see -
 * 		Documentation/RCU/ *.txt
 *
 */
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/rcupdate.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <asm/atomic.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/completion.h>
#include <linux/moduleparam.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/mutex.h>
#include <linux/rcupreempt_trace.h>
#include <linux/debugfs.h>

static struct mutex rcupreempt_trace_mutex;
static char *rcupreempt_trace_buf;
#define RCUPREEMPT_TRACE_BUF_SIZE 4096

void rcupreempt_trace_move2done(struct rcupreempt_trace *trace)
{
	trace->done_length += trace->wait_length;
	trace->done_add += trace->wait_length;
	trace->wait_length = 0;
}
void rcupreempt_trace_move2wait(struct rcupreempt_trace *trace)
{
	trace->wait_length += trace->next_length;
	trace->wait_add += trace->next_length;
	trace->next_length = 0;
}
void rcupreempt_trace_try_flip_1(struct rcupreempt_trace *trace)
{
	atomic_inc(&trace->rcu_try_flip_1);
}
void rcupreempt_trace_try_flip_e1(struct rcupreempt_trace *trace)
{
	atomic_inc(&trace->rcu_try_flip_e1);
}
void rcupreempt_trace_try_flip_i1(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_i1++;
}
void rcupreempt_trace_try_flip_ie1(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_ie1++;
}
void rcupreempt_trace_try_flip_g1(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_g1++;
}
void rcupreempt_trace_try_flip_a1(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_a1++;
}
void rcupreempt_trace_try_flip_ae1(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_ae1++;
}
void rcupreempt_trace_try_flip_a2(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_a2++;
}
void rcupreempt_trace_try_flip_z1(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_z1++;
}
void rcupreempt_trace_try_flip_ze1(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_ze1++;
}
void rcupreempt_trace_try_flip_z2(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_z2++;
}
void rcupreempt_trace_try_flip_m1(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_m1++;
}
void rcupreempt_trace_try_flip_me1(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_me1++;
}
void rcupreempt_trace_try_flip_m2(struct rcupreempt_trace *trace)
{
	trace->rcu_try_flip_m2++;
}
void rcupreempt_trace_check_callbacks(struct rcupreempt_trace *trace)
{
	trace->rcu_check_callbacks++;
}
void rcupreempt_trace_done_remove(struct rcupreempt_trace *trace)
{
	trace->done_remove += trace->done_length;
	trace->done_length = 0;
}
void rcupreempt_trace_invoke(struct rcupreempt_trace *trace)
{
	atomic_inc(&trace->done_invoked);
}
void rcupreempt_trace_next_add(struct rcupreempt_trace *trace)
{
	trace->next_add++;
	trace->next_length++;
}

static void rcupreempt_trace_sum(struct rcupreempt_trace *sp)
{
	struct rcupreempt_trace *cp;
	int cpu;

	memset(sp, 0, sizeof(*sp));
	for_each_possible_cpu(cpu) {
		cp = rcupreempt_trace_cpu(cpu);
		sp->next_length += cp->next_length;
		sp->next_add += cp->next_add;
		sp->wait_length += cp->wait_length;
		sp->wait_add += cp->wait_add;
		sp->done_length += cp->done_length;
		sp->done_add += cp->done_add;
		sp->done_remove += cp->done_remove;
		atomic_add(atomic_read(&cp->done_invoked), &sp->done_invoked);
		sp->rcu_check_callbacks += cp->rcu_check_callbacks;
		atomic_add(atomic_read(&cp->rcu_try_flip_1),
			   &sp->rcu_try_flip_1);
		atomic_add(atomic_read(&cp->rcu_try_flip_e1),
			   &sp->rcu_try_flip_e1);
		sp->rcu_try_flip_i1 += cp->rcu_try_flip_i1;
		sp->rcu_try_flip_ie1 += cp->rcu_try_flip_ie1;
		sp->rcu_try_flip_g1 += cp->rcu_try_flip_g1;
		sp->rcu_try_flip_a1 += cp->rcu_try_flip_a1;
		sp->rcu_try_flip_ae1 += cp->rcu_try_flip_ae1;
		sp->rcu_try_flip_a2 += cp->rcu_try_flip_a2;
		sp->rcu_try_flip_z1 += cp->rcu_try_flip_z1;
		sp->rcu_try_flip_ze1 += cp->rcu_try_flip_ze1;
		sp->rcu_try_flip_z2 += cp->rcu_try_flip_z2;
		sp->rcu_try_flip_m1 += cp->rcu_try_flip_m1;
		sp->rcu_try_flip_me1 += cp->rcu_try_flip_me1;
		sp->rcu_try_flip_m2 += cp->rcu_try_flip_m2;
	}
}

static ssize_t rcustats_read(struct file *filp, char __user *buffer,
				size_t count, loff_t *ppos)
{
	struct rcupreempt_trace trace;
	ssize_t bcount;
	int cnt = 0;

	rcupreempt_trace_sum(&trace);
	mutex_lock(&rcupreempt_trace_mutex);
	snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt,
		 "ggp=%ld rcc=%ld\n",
		 rcu_batches_completed(),
		 trace.rcu_check_callbacks);
	snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt,
		 "na=%ld nl=%ld wa=%ld wl=%ld da=%ld dl=%ld dr=%ld di=%d\n"
		 "1=%d e1=%d i1=%ld ie1=%ld g1=%ld a1=%ld ae1=%ld a2=%ld\n"
		 "z1=%ld ze1=%ld z2=%ld m1=%ld me1=%ld m2=%ld\n",

		 trace.next_add, trace.next_length,
		 trace.wait_add, trace.wait_length,
		 trace.done_add, trace.done_length,
		 trace.done_remove, atomic_read(&trace.done_invoked),
		 atomic_read(&trace.rcu_try_flip_1),
		 atomic_read(&trace.rcu_try_flip_e1),
		 trace.rcu_try_flip_i1, trace.rcu_try_flip_ie1,
		 trace.rcu_try_flip_g1,
		 trace.rcu_try_flip_a1, trace.rcu_try_flip_ae1,
			 trace.rcu_try_flip_a2,
		 trace.rcu_try_flip_z1, trace.rcu_try_flip_ze1,
			 trace.rcu_try_flip_z2,
		 trace.rcu_try_flip_m1, trace.rcu_try_flip_me1,
			trace.rcu_try_flip_m2);
	bcount = simple_read_from_buffer(buffer, count, ppos,
			rcupreempt_trace_buf, strlen(rcupreempt_trace_buf));
	mutex_unlock(&rcupreempt_trace_mutex);
	return bcount;
}

static ssize_t rcugp_read(struct file *filp, char __user *buffer,
				size_t count, loff_t *ppos)
{
	long oldgp = rcu_batches_completed();
	ssize_t bcount;

	mutex_lock(&rcupreempt_trace_mutex);
	synchronize_rcu();
	snprintf(rcupreempt_trace_buf, RCUPREEMPT_TRACE_BUF_SIZE,
		"oldggp=%ld  newggp=%ld\n", oldgp, rcu_batches_completed());
	bcount = simple_read_from_buffer(buffer, count, ppos,
			rcupreempt_trace_buf, strlen(rcupreempt_trace_buf));
	mutex_unlock(&rcupreempt_trace_mutex);
	return bcount;
}

static ssize_t rcuctrs_read(struct file *filp, char __user *buffer,
				size_t count, loff_t *ppos)
{
	int cnt = 0;
	int cpu;
	int f = rcu_batches_completed() & 0x1;
	ssize_t bcount;

	mutex_lock(&rcupreempt_trace_mutex);

	cnt += snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE,
				"CPU last cur F M\n");
	for_each_possible_cpu(cpu) {
		long *flipctr = rcupreempt_flipctr(cpu);
		cnt += snprintf(&rcupreempt_trace_buf[cnt],
				RCUPREEMPT_TRACE_BUF_SIZE - cnt,
					"%3d%c %4ld %3ld %d %d\n",
			       cpu,
			       cpu_is_offline(cpu) ? '!' : ' ',
			       flipctr[!f],
			       flipctr[f],
			       rcupreempt_flip_flag(cpu),
			       rcupreempt_mb_flag(cpu));
	}
	cnt += snprintf(&rcupreempt_trace_buf[cnt],
			RCUPREEMPT_TRACE_BUF_SIZE - cnt,
			"ggp = %ld, state = %s\n",
			rcu_batches_completed(),
			rcupreempt_try_flip_state_name());
	cnt += snprintf(&rcupreempt_trace_buf[cnt],
			RCUPREEMPT_TRACE_BUF_SIZE - cnt,
			"\n");
	bcount = simple_read_from_buffer(buffer, count, ppos,
			rcupreempt_trace_buf, strlen(rcupreempt_trace_buf));
	mutex_unlock(&rcupreempt_trace_mutex);
	return bcount;
}

static struct file_operations rcustats_fops = {
	.owner = THIS_MODULE,
	.read = rcustats_read,
};

static struct file_operations rcugp_fops = {
	.owner = THIS_MODULE,
	.read = rcugp_read,
};

static struct file_operations rcuctrs_fops = {
	.owner = THIS_MODULE,
	.read = rcuctrs_read,
};

static struct dentry *rcudir, *statdir, *ctrsdir, *gpdir;
static int rcupreempt_debugfs_init(void)
{
	rcudir = debugfs_create_dir("rcu", NULL);
	if (!rcudir)
		goto out;
	statdir = debugfs_create_file("rcustats", 0444, rcudir,
						NULL, &rcustats_fops);
	if (!statdir)
		goto free_out;

	gpdir = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
	if (!gpdir)
		goto free_out;

	ctrsdir = debugfs_create_file("rcuctrs", 0444, rcudir,
						NULL, &rcuctrs_fops);
	if (!ctrsdir)
		goto free_out;
	return 0;
free_out:
	if (statdir)
		debugfs_remove(statdir);
	if (gpdir)
		debugfs_remove(gpdir);
	debugfs_remove(rcudir);
out:
	return 1;
}

static int __init rcupreempt_trace_init(void)
{
	int ret;

	mutex_init(&rcupreempt_trace_mutex);
	rcupreempt_trace_buf = kmalloc(RCUPREEMPT_TRACE_BUF_SIZE, GFP_KERNEL);
	if (!rcupreempt_trace_buf)
		return 1;
	ret = rcupreempt_debugfs_init();
	if (ret)
		kfree(rcupreempt_trace_buf);
	return ret;
}

static void __exit rcupreempt_trace_cleanup(void)
{
	debugfs_remove(statdir);
	debugfs_remove(gpdir);
	debugfs_remove(ctrsdir);
	debugfs_remove(rcudir);
	kfree(rcupreempt_trace_buf);
}


module_init(rcupreempt_trace_init);
module_exit(rcupreempt_trace_cleanup);