rcu: Merge preemptable-RCU functionality into hierarchical RCU
[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=%ld g=%ld pq=%d pqc=%ld 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\n", rdp->qlen, rdp->blimit);
68 }
69
70 #define PRINT_RCU_DATA(name, func, m) \
71         do { \
72                 int _p_r_d_i; \
73                 \
74                 for_each_possible_cpu(_p_r_d_i) \
75                         func(m, &per_cpu(name, _p_r_d_i)); \
76         } while (0)
77
78 static int show_rcudata(struct seq_file *m, void *unused)
79 {
80 #ifdef CONFIG_TREE_PREEMPT_RCU
81         seq_puts(m, "rcu_preempt:\n");
82         PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data, m);
83 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
84         seq_puts(m, "rcu_sched:\n");
85         PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data, m);
86         seq_puts(m, "rcu_bh:\n");
87         PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data, m);
88         return 0;
89 }
90
91 static int rcudata_open(struct inode *inode, struct file *file)
92 {
93         return single_open(file, show_rcudata, NULL);
94 }
95
96 static struct file_operations rcudata_fops = {
97         .owner = THIS_MODULE,
98         .open = rcudata_open,
99         .read = seq_read,
100         .llseek = seq_lseek,
101         .release = single_release,
102 };
103
104 static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
105 {
106         if (!rdp->beenonline)
107                 return;
108         seq_printf(m, "%d,%s,%ld,%ld,%d,%ld,%d",
109                    rdp->cpu,
110                    cpu_is_offline(rdp->cpu) ? "\"N\"" : "\"Y\"",
111                    rdp->completed, rdp->gpnum,
112                    rdp->passed_quiesc, rdp->passed_quiesc_completed,
113                    rdp->qs_pending);
114 #ifdef CONFIG_NO_HZ
115         seq_printf(m, ",%d,%d,%d,%lu",
116                    rdp->dynticks->dynticks,
117                    rdp->dynticks->dynticks_nesting,
118                    rdp->dynticks->dynticks_nmi,
119                    rdp->dynticks_fqs);
120 #endif /* #ifdef CONFIG_NO_HZ */
121         seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
122         seq_printf(m, ",%ld,%ld\n", rdp->qlen, rdp->blimit);
123 }
124
125 static int show_rcudata_csv(struct seq_file *m, void *unused)
126 {
127         seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\",");
128 #ifdef CONFIG_NO_HZ
129         seq_puts(m, "\"dt\",\"dt nesting\",\"dn\",\"df\",");
130 #endif /* #ifdef CONFIG_NO_HZ */
131         seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\"\n");
132 #ifdef CONFIG_TREE_PREEMPT_RCU
133         seq_puts(m, "\"rcu_preempt:\"\n");
134         PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data_csv, m);
135 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
136         seq_puts(m, "\"rcu_sched:\"\n");
137         PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data_csv, m);
138         seq_puts(m, "\"rcu_bh:\"\n");
139         PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data_csv, m);
140         return 0;
141 }
142
143 static int rcudata_csv_open(struct inode *inode, struct file *file)
144 {
145         return single_open(file, show_rcudata_csv, NULL);
146 }
147
148 static struct file_operations rcudata_csv_fops = {
149         .owner = THIS_MODULE,
150         .open = rcudata_csv_open,
151         .read = seq_read,
152         .llseek = seq_lseek,
153         .release = single_release,
154 };
155
156 static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
157 {
158         int level = 0;
159         struct rcu_node *rnp;
160
161         seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x "
162                       "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
163                    rsp->completed, rsp->gpnum, rsp->signaled,
164                    (long)(rsp->jiffies_force_qs - jiffies),
165                    (int)(jiffies & 0xffff),
166                    rsp->n_force_qs, rsp->n_force_qs_ngp,
167                    rsp->n_force_qs - rsp->n_force_qs_ngp,
168                    rsp->n_force_qs_lh);
169         for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
170                 if (rnp->level != level) {
171                         seq_puts(m, "\n");
172                         level = rnp->level;
173                 }
174                 seq_printf(m, "%lx/%lx %d:%d ^%d    ",
175                            rnp->qsmask, rnp->qsmaskinit,
176                            rnp->grplo, rnp->grphi, rnp->grpnum);
177         }
178         seq_puts(m, "\n");
179 }
180
181 static int show_rcuhier(struct seq_file *m, void *unused)
182 {
183 #ifdef CONFIG_TREE_PREEMPT_RCU
184         seq_puts(m, "rcu_preempt:\n");
185         print_one_rcu_state(m, &rcu_preempt_state);
186 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
187         seq_puts(m, "rcu_sched:\n");
188         print_one_rcu_state(m, &rcu_sched_state);
189         seq_puts(m, "rcu_bh:\n");
190         print_one_rcu_state(m, &rcu_bh_state);
191         return 0;
192 }
193
194 static int rcuhier_open(struct inode *inode, struct file *file)
195 {
196         return single_open(file, show_rcuhier, NULL);
197 }
198
199 static struct file_operations rcuhier_fops = {
200         .owner = THIS_MODULE,
201         .open = rcuhier_open,
202         .read = seq_read,
203         .llseek = seq_lseek,
204         .release = single_release,
205 };
206
207 static int show_rcugp(struct seq_file *m, void *unused)
208 {
209 #ifdef CONFIG_TREE_PREEMPT_RCU
210         seq_printf(m, "rcu_preempt: completed=%ld  gpnum=%ld\n",
211                    rcu_preempt_state.completed, rcu_preempt_state.gpnum);
212 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
213         seq_printf(m, "rcu_sched: completed=%ld  gpnum=%ld\n",
214                    rcu_sched_state.completed, rcu_sched_state.gpnum);
215         seq_printf(m, "rcu_bh: completed=%ld  gpnum=%ld\n",
216                    rcu_bh_state.completed, rcu_bh_state.gpnum);
217         return 0;
218 }
219
220 static int rcugp_open(struct inode *inode, struct file *file)
221 {
222         return single_open(file, show_rcugp, NULL);
223 }
224
225 static struct file_operations rcugp_fops = {
226         .owner = THIS_MODULE,
227         .open = rcugp_open,
228         .read = seq_read,
229         .llseek = seq_lseek,
230         .release = single_release,
231 };
232
233 static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
234 {
235         seq_printf(m, "%3d%cnp=%ld "
236                    "qsp=%ld cbr=%ld cng=%ld gpc=%ld gps=%ld nf=%ld nn=%ld\n",
237                    rdp->cpu,
238                    cpu_is_offline(rdp->cpu) ? '!' : ' ',
239                    rdp->n_rcu_pending,
240                    rdp->n_rp_qs_pending,
241                    rdp->n_rp_cb_ready,
242                    rdp->n_rp_cpu_needs_gp,
243                    rdp->n_rp_gp_completed,
244                    rdp->n_rp_gp_started,
245                    rdp->n_rp_need_fqs,
246                    rdp->n_rp_need_nothing);
247 }
248
249 static void print_rcu_pendings(struct seq_file *m, struct rcu_state *rsp)
250 {
251         int cpu;
252         struct rcu_data *rdp;
253
254         for_each_possible_cpu(cpu) {
255                 rdp = rsp->rda[cpu];
256                 if (rdp->beenonline)
257                         print_one_rcu_pending(m, rdp);
258         }
259 }
260
261 static int show_rcu_pending(struct seq_file *m, void *unused)
262 {
263 #ifdef CONFIG_TREE_PREEMPT_RCU
264         seq_puts(m, "rcu_preempt:\n");
265         print_rcu_pendings(m, &rcu_preempt_state);
266 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
267         seq_puts(m, "rcu_sched:\n");
268         print_rcu_pendings(m, &rcu_sched_state);
269         seq_puts(m, "rcu_bh:\n");
270         print_rcu_pendings(m, &rcu_bh_state);
271         return 0;
272 }
273
274 static int rcu_pending_open(struct inode *inode, struct file *file)
275 {
276         return single_open(file, show_rcu_pending, NULL);
277 }
278
279 static struct file_operations rcu_pending_fops = {
280         .owner = THIS_MODULE,
281         .open = rcu_pending_open,
282         .read = seq_read,
283         .llseek = seq_lseek,
284         .release = single_release,
285 };
286
287 static struct dentry *rcudir;
288
289 static int __init rcuclassic_trace_init(void)
290 {
291         struct dentry *retval;
292
293         rcudir = debugfs_create_dir("rcu", NULL);
294         if (!rcudir)
295                 goto free_out;
296
297         retval = debugfs_create_file("rcudata", 0444, rcudir,
298                                                 NULL, &rcudata_fops);
299         if (!retval)
300                 goto free_out;
301
302         retval = debugfs_create_file("rcudata.csv", 0444, rcudir,
303                                                 NULL, &rcudata_csv_fops);
304         if (!retval)
305                 goto free_out;
306
307         retval = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
308         if (!retval)
309                 goto free_out;
310
311         retval = debugfs_create_file("rcuhier", 0444, rcudir,
312                                                 NULL, &rcuhier_fops);
313         if (!retval)
314                 goto free_out;
315
316         retval = debugfs_create_file("rcu_pending", 0444, rcudir,
317                                                 NULL, &rcu_pending_fops);
318         if (!retval)
319                 goto free_out;
320         return 0;
321 free_out:
322         debugfs_remove_recursive(rcudir);
323         return 1;
324 }
325
326 static void __exit rcuclassic_trace_cleanup(void)
327 {
328         debugfs_remove_recursive(rcudir);
329 }
330
331
332 module_init(rcuclassic_trace_init);
333 module_exit(rcuclassic_trace_cleanup);
334
335 MODULE_AUTHOR("Paul E. McKenney");
336 MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
337 MODULE_LICENSE("GPL");