78ad3c35b6838de4d36d1007007e189921ef4dfe
[linux-2.6.git] / kernel / rcutree_trace.c
1 /*
2  * Read-Copy Update tracing for classic implementation
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17  *
18  * Copyright IBM Corporation, 2008
19  *
20  * Papers:  http://www.rdrop.com/users/paulmck/RCU
21  *
22  * For detailed explanation of Read-Copy Update mechanism see -
23  *              Documentation/RCU
24  *
25  */
26 #include <linux/types.h>
27 #include <linux/kernel.h>
28 #include <linux/init.h>
29 #include <linux/spinlock.h>
30 #include <linux/smp.h>
31 #include <linux/rcupdate.h>
32 #include <linux/interrupt.h>
33 #include <linux/sched.h>
34 #include <asm/atomic.h>
35 #include <linux/bitops.h>
36 #include <linux/module.h>
37 #include <linux/completion.h>
38 #include <linux/moduleparam.h>
39 #include <linux/percpu.h>
40 #include <linux/notifier.h>
41 #include <linux/cpu.h>
42 #include <linux/mutex.h>
43 #include <linux/debugfs.h>
44 #include <linux/seq_file.h>
45
46 #define RCU_TREE_NONCORE
47 #include "rcutree.h"
48
49 static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
50 {
51         if (!rdp->beenonline)
52                 return;
53         seq_printf(m, "%3d%cc=%lu g=%lu pq=%d pqc=%lu qp=%d",
54                    rdp->cpu,
55                    cpu_is_offline(rdp->cpu) ? '!' : ' ',
56                    rdp->completed, rdp->gpnum,
57                    rdp->passed_quiesc, rdp->passed_quiesc_completed,
58                    rdp->qs_pending);
59 #ifdef CONFIG_NO_HZ
60         seq_printf(m, " dt=%d/%d dn=%d df=%lu",
61                    rdp->dynticks->dynticks,
62                    rdp->dynticks->dynticks_nesting,
63                    rdp->dynticks->dynticks_nmi,
64                    rdp->dynticks_fqs);
65 #endif /* #ifdef CONFIG_NO_HZ */
66         seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi);
67         seq_printf(m, " ql=%ld b=%ld", rdp->qlen, rdp->blimit);
68         seq_printf(m, " ci=%lu co=%lu ca=%lu\n",
69                    rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
70 }
71
72 #define PRINT_RCU_DATA(name, func, m) \
73         do { \
74                 int _p_r_d_i; \
75                 \
76                 for_each_possible_cpu(_p_r_d_i) \
77                         func(m, &per_cpu(name, _p_r_d_i)); \
78         } while (0)
79
80 static int show_rcudata(struct seq_file *m, void *unused)
81 {
82 #ifdef CONFIG_TREE_PREEMPT_RCU
83         seq_puts(m, "rcu_preempt:\n");
84         PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data, m);
85 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
86         seq_puts(m, "rcu_sched:\n");
87         PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data, m);
88         seq_puts(m, "rcu_bh:\n");
89         PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data, m);
90         return 0;
91 }
92
93 static int rcudata_open(struct inode *inode, struct file *file)
94 {
95         return single_open(file, show_rcudata, NULL);
96 }
97
98 static const struct file_operations rcudata_fops = {
99         .owner = THIS_MODULE,
100         .open = rcudata_open,
101         .read = seq_read,
102         .llseek = seq_lseek,
103         .release = single_release,
104 };
105
106 static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
107 {
108         if (!rdp->beenonline)
109                 return;
110         seq_printf(m, "%d,%s,%lu,%lu,%d,%lu,%d",
111                    rdp->cpu,
112                    cpu_is_offline(rdp->cpu) ? "\"N\"" : "\"Y\"",
113                    rdp->completed, rdp->gpnum,
114                    rdp->passed_quiesc, rdp->passed_quiesc_completed,
115                    rdp->qs_pending);
116 #ifdef CONFIG_NO_HZ
117         seq_printf(m, ",%d,%d,%d,%lu",
118                    rdp->dynticks->dynticks,
119                    rdp->dynticks->dynticks_nesting,
120                    rdp->dynticks->dynticks_nmi,
121                    rdp->dynticks_fqs);
122 #endif /* #ifdef CONFIG_NO_HZ */
123         seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
124         seq_printf(m, ",%ld,%ld", rdp->qlen, rdp->blimit);
125         seq_printf(m, ",%lu,%lu,%lu\n",
126                    rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
127 }
128
129 static int show_rcudata_csv(struct seq_file *m, void *unused)
130 {
131         seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\",");
132 #ifdef CONFIG_NO_HZ
133         seq_puts(m, "\"dt\",\"dt nesting\",\"dn\",\"df\",");
134 #endif /* #ifdef CONFIG_NO_HZ */
135         seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\",\"ci\",\"co\",\"ca\"\n");
136 #ifdef CONFIG_TREE_PREEMPT_RCU
137         seq_puts(m, "\"rcu_preempt:\"\n");
138         PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data_csv, m);
139 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
140         seq_puts(m, "\"rcu_sched:\"\n");
141         PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data_csv, m);
142         seq_puts(m, "\"rcu_bh:\"\n");
143         PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data_csv, m);
144         return 0;
145 }
146
147 static int rcudata_csv_open(struct inode *inode, struct file *file)
148 {
149         return single_open(file, show_rcudata_csv, NULL);
150 }
151
152 static const struct file_operations rcudata_csv_fops = {
153         .owner = THIS_MODULE,
154         .open = rcudata_csv_open,
155         .read = seq_read,
156         .llseek = seq_lseek,
157         .release = single_release,
158 };
159
160 static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
161 {
162         unsigned long gpnum;
163         int level = 0;
164         int phase;
165         struct rcu_node *rnp;
166
167         gpnum = rsp->gpnum;
168         seq_printf(m, "c=%lu g=%lu s=%d jfq=%ld j=%x "
169                       "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld\n",
170                    rsp->completed, gpnum, rsp->signaled,
171                    (long)(rsp->jiffies_force_qs - jiffies),
172                    (int)(jiffies & 0xffff),
173                    rsp->n_force_qs, rsp->n_force_qs_ngp,
174                    rsp->n_force_qs - rsp->n_force_qs_ngp,
175                    rsp->n_force_qs_lh, rsp->orphan_qlen);
176         for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
177                 if (rnp->level != level) {
178                         seq_puts(m, "\n");
179                         level = rnp->level;
180                 }
181                 phase = gpnum & 0x1;
182                 seq_printf(m, "%lx/%lx %c%c>%c%c %d:%d ^%d    ",
183                            rnp->qsmask, rnp->qsmaskinit,
184                            "T."[list_empty(&rnp->blocked_tasks[phase])],
185                            "E."[list_empty(&rnp->blocked_tasks[phase + 2])],
186                            "T."[list_empty(&rnp->blocked_tasks[!phase])],
187                            "E."[list_empty(&rnp->blocked_tasks[!phase + 2])],
188                            rnp->grplo, rnp->grphi, rnp->grpnum);
189         }
190         seq_puts(m, "\n");
191 }
192
193 static int show_rcuhier(struct seq_file *m, void *unused)
194 {
195 #ifdef CONFIG_TREE_PREEMPT_RCU
196         seq_puts(m, "rcu_preempt:\n");
197         print_one_rcu_state(m, &rcu_preempt_state);
198 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
199         seq_puts(m, "rcu_sched:\n");
200         print_one_rcu_state(m, &rcu_sched_state);
201         seq_puts(m, "rcu_bh:\n");
202         print_one_rcu_state(m, &rcu_bh_state);
203         return 0;
204 }
205
206 static int rcuhier_open(struct inode *inode, struct file *file)
207 {
208         return single_open(file, show_rcuhier, NULL);
209 }
210
211 static const struct file_operations rcuhier_fops = {
212         .owner = THIS_MODULE,
213         .open = rcuhier_open,
214         .read = seq_read,
215         .llseek = seq_lseek,
216         .release = single_release,
217 };
218
219 static int show_rcugp(struct seq_file *m, void *unused)
220 {
221 #ifdef CONFIG_TREE_PREEMPT_RCU
222         seq_printf(m, "rcu_preempt: completed=%ld  gpnum=%lu\n",
223                    rcu_preempt_state.completed, rcu_preempt_state.gpnum);
224 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
225         seq_printf(m, "rcu_sched: completed=%ld  gpnum=%lu\n",
226                    rcu_sched_state.completed, rcu_sched_state.gpnum);
227         seq_printf(m, "rcu_bh: completed=%ld  gpnum=%lu\n",
228                    rcu_bh_state.completed, rcu_bh_state.gpnum);
229         return 0;
230 }
231
232 static int rcugp_open(struct inode *inode, struct file *file)
233 {
234         return single_open(file, show_rcugp, NULL);
235 }
236
237 static const struct file_operations rcugp_fops = {
238         .owner = THIS_MODULE,
239         .open = rcugp_open,
240         .read = seq_read,
241         .llseek = seq_lseek,
242         .release = single_release,
243 };
244
245 static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
246 {
247         seq_printf(m, "%3d%cnp=%ld "
248                    "qsp=%ld rpq=%ld cbr=%ld cng=%ld "
249                    "gpc=%ld gps=%ld nf=%ld nn=%ld\n",
250                    rdp->cpu,
251                    cpu_is_offline(rdp->cpu) ? '!' : ' ',
252                    rdp->n_rcu_pending,
253                    rdp->n_rp_qs_pending,
254                    rdp->n_rp_report_qs,
255                    rdp->n_rp_cb_ready,
256                    rdp->n_rp_cpu_needs_gp,
257                    rdp->n_rp_gp_completed,
258                    rdp->n_rp_gp_started,
259                    rdp->n_rp_need_fqs,
260                    rdp->n_rp_need_nothing);
261 }
262
263 static void print_rcu_pendings(struct seq_file *m, struct rcu_state *rsp)
264 {
265         int cpu;
266         struct rcu_data *rdp;
267
268         for_each_possible_cpu(cpu) {
269                 rdp = per_cpu_ptr(rsp->rda, cpu);
270                 if (rdp->beenonline)
271                         print_one_rcu_pending(m, rdp);
272         }
273 }
274
275 static int show_rcu_pending(struct seq_file *m, void *unused)
276 {
277 #ifdef CONFIG_TREE_PREEMPT_RCU
278         seq_puts(m, "rcu_preempt:\n");
279         print_rcu_pendings(m, &rcu_preempt_state);
280 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
281         seq_puts(m, "rcu_sched:\n");
282         print_rcu_pendings(m, &rcu_sched_state);
283         seq_puts(m, "rcu_bh:\n");
284         print_rcu_pendings(m, &rcu_bh_state);
285         return 0;
286 }
287
288 static int rcu_pending_open(struct inode *inode, struct file *file)
289 {
290         return single_open(file, show_rcu_pending, NULL);
291 }
292
293 static const struct file_operations rcu_pending_fops = {
294         .owner = THIS_MODULE,
295         .open = rcu_pending_open,
296         .read = seq_read,
297         .llseek = seq_lseek,
298         .release = single_release,
299 };
300
301 static struct dentry *rcudir;
302
303 static int __init rcutree_trace_init(void)
304 {
305         struct dentry *retval;
306
307         rcudir = debugfs_create_dir("rcu", NULL);
308         if (!rcudir)
309                 goto free_out;
310
311         retval = debugfs_create_file("rcudata", 0444, rcudir,
312                                                 NULL, &rcudata_fops);
313         if (!retval)
314                 goto free_out;
315
316         retval = debugfs_create_file("rcudata.csv", 0444, rcudir,
317                                                 NULL, &rcudata_csv_fops);
318         if (!retval)
319                 goto free_out;
320
321         retval = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
322         if (!retval)
323                 goto free_out;
324
325         retval = debugfs_create_file("rcuhier", 0444, rcudir,
326                                                 NULL, &rcuhier_fops);
327         if (!retval)
328                 goto free_out;
329
330         retval = debugfs_create_file("rcu_pending", 0444, rcudir,
331                                                 NULL, &rcu_pending_fops);
332         if (!retval)
333                 goto free_out;
334         return 0;
335 free_out:
336         debugfs_remove_recursive(rcudir);
337         return 1;
338 }
339
340 static void __exit rcutree_trace_cleanup(void)
341 {
342         debugfs_remove_recursive(rcudir);
343 }
344
345
346 module_init(rcutree_trace_init);
347 module_exit(rcutree_trace_cleanup);
348
349 MODULE_AUTHOR("Paul E. McKenney");
350 MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
351 MODULE_LICENSE("GPL");