dm mpath: fix NULL pointer dereference when path parameters missing
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / rcutree_trace.c
blobd45db2e35d27a1c3aea36ad6ff299fdf73cb7e74
1 /*
2 * Read-Copy Update tracing for classic implementation
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.
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.
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.
18 * Copyright IBM Corporation, 2008
20 * Papers: http://www.rdrop.com/users/paulmck/RCU
22 * For detailed explanation of Read-Copy Update mechanism see -
23 * Documentation/RCU
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>
46 #define RCU_TREE_NONCORE
47 #include "rcutree.h"
49 static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
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\n", rdp->qlen, rdp->blimit);
70 #define PRINT_RCU_DATA(name, func, m) \
71 do { \
72 int _p_r_d_i; \
74 for_each_possible_cpu(_p_r_d_i) \
75 func(m, &per_cpu(name, _p_r_d_i)); \
76 } while (0)
78 static int show_rcudata(struct seq_file *m, void *unused)
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;
91 static int rcudata_open(struct inode *inode, struct file *file)
93 return single_open(file, show_rcudata, NULL);
96 static const 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,
104 static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
106 if (!rdp->beenonline)
107 return;
108 seq_printf(m, "%d,%s,%lu,%lu,%d,%lu,%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);
125 static int show_rcudata_csv(struct seq_file *m, void *unused)
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;
143 static int rcudata_csv_open(struct inode *inode, struct file *file)
145 return single_open(file, show_rcudata_csv, NULL);
148 static const 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,
156 static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
158 unsigned long gpnum;
159 int level = 0;
160 int phase;
161 struct rcu_node *rnp;
163 gpnum = rsp->gpnum;
164 seq_printf(m, "c=%lu g=%lu s=%d jfq=%ld j=%x "
165 "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld\n",
166 rsp->completed, gpnum, rsp->signaled,
167 (long)(rsp->jiffies_force_qs - jiffies),
168 (int)(jiffies & 0xffff),
169 rsp->n_force_qs, rsp->n_force_qs_ngp,
170 rsp->n_force_qs - rsp->n_force_qs_ngp,
171 rsp->n_force_qs_lh, rsp->orphan_qlen);
172 for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
173 if (rnp->level != level) {
174 seq_puts(m, "\n");
175 level = rnp->level;
177 phase = gpnum & 0x1;
178 seq_printf(m, "%lx/%lx %c%c>%c%c %d:%d ^%d ",
179 rnp->qsmask, rnp->qsmaskinit,
180 "T."[list_empty(&rnp->blocked_tasks[phase])],
181 "E."[list_empty(&rnp->blocked_tasks[phase + 2])],
182 "T."[list_empty(&rnp->blocked_tasks[!phase])],
183 "E."[list_empty(&rnp->blocked_tasks[!phase + 2])],
184 rnp->grplo, rnp->grphi, rnp->grpnum);
186 seq_puts(m, "\n");
189 static int show_rcuhier(struct seq_file *m, void *unused)
191 #ifdef CONFIG_TREE_PREEMPT_RCU
192 seq_puts(m, "rcu_preempt:\n");
193 print_one_rcu_state(m, &rcu_preempt_state);
194 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
195 seq_puts(m, "rcu_sched:\n");
196 print_one_rcu_state(m, &rcu_sched_state);
197 seq_puts(m, "rcu_bh:\n");
198 print_one_rcu_state(m, &rcu_bh_state);
199 return 0;
202 static int rcuhier_open(struct inode *inode, struct file *file)
204 return single_open(file, show_rcuhier, NULL);
207 static const struct file_operations rcuhier_fops = {
208 .owner = THIS_MODULE,
209 .open = rcuhier_open,
210 .read = seq_read,
211 .llseek = seq_lseek,
212 .release = single_release,
215 static int show_rcugp(struct seq_file *m, void *unused)
217 #ifdef CONFIG_TREE_PREEMPT_RCU
218 seq_printf(m, "rcu_preempt: completed=%ld gpnum=%lu\n",
219 rcu_preempt_state.completed, rcu_preempt_state.gpnum);
220 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
221 seq_printf(m, "rcu_sched: completed=%ld gpnum=%lu\n",
222 rcu_sched_state.completed, rcu_sched_state.gpnum);
223 seq_printf(m, "rcu_bh: completed=%ld gpnum=%lu\n",
224 rcu_bh_state.completed, rcu_bh_state.gpnum);
225 return 0;
228 static int rcugp_open(struct inode *inode, struct file *file)
230 return single_open(file, show_rcugp, NULL);
233 static const struct file_operations rcugp_fops = {
234 .owner = THIS_MODULE,
235 .open = rcugp_open,
236 .read = seq_read,
237 .llseek = seq_lseek,
238 .release = single_release,
241 static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
243 seq_printf(m, "%3d%cnp=%ld "
244 "qsp=%ld cbr=%ld cng=%ld gpc=%ld gps=%ld nf=%ld nn=%ld\n",
245 rdp->cpu,
246 cpu_is_offline(rdp->cpu) ? '!' : ' ',
247 rdp->n_rcu_pending,
248 rdp->n_rp_qs_pending,
249 rdp->n_rp_cb_ready,
250 rdp->n_rp_cpu_needs_gp,
251 rdp->n_rp_gp_completed,
252 rdp->n_rp_gp_started,
253 rdp->n_rp_need_fqs,
254 rdp->n_rp_need_nothing);
257 static void print_rcu_pendings(struct seq_file *m, struct rcu_state *rsp)
259 int cpu;
260 struct rcu_data *rdp;
262 for_each_possible_cpu(cpu) {
263 rdp = rsp->rda[cpu];
264 if (rdp->beenonline)
265 print_one_rcu_pending(m, rdp);
269 static int show_rcu_pending(struct seq_file *m, void *unused)
271 #ifdef CONFIG_TREE_PREEMPT_RCU
272 seq_puts(m, "rcu_preempt:\n");
273 print_rcu_pendings(m, &rcu_preempt_state);
274 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
275 seq_puts(m, "rcu_sched:\n");
276 print_rcu_pendings(m, &rcu_sched_state);
277 seq_puts(m, "rcu_bh:\n");
278 print_rcu_pendings(m, &rcu_bh_state);
279 return 0;
282 static int rcu_pending_open(struct inode *inode, struct file *file)
284 return single_open(file, show_rcu_pending, NULL);
287 static const struct file_operations rcu_pending_fops = {
288 .owner = THIS_MODULE,
289 .open = rcu_pending_open,
290 .read = seq_read,
291 .llseek = seq_lseek,
292 .release = single_release,
295 static struct dentry *rcudir;
297 static int __init rcuclassic_trace_init(void)
299 struct dentry *retval;
301 rcudir = debugfs_create_dir("rcu", NULL);
302 if (!rcudir)
303 goto free_out;
305 retval = debugfs_create_file("rcudata", 0444, rcudir,
306 NULL, &rcudata_fops);
307 if (!retval)
308 goto free_out;
310 retval = debugfs_create_file("rcudata.csv", 0444, rcudir,
311 NULL, &rcudata_csv_fops);
312 if (!retval)
313 goto free_out;
315 retval = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
316 if (!retval)
317 goto free_out;
319 retval = debugfs_create_file("rcuhier", 0444, rcudir,
320 NULL, &rcuhier_fops);
321 if (!retval)
322 goto free_out;
324 retval = debugfs_create_file("rcu_pending", 0444, rcudir,
325 NULL, &rcu_pending_fops);
326 if (!retval)
327 goto free_out;
328 return 0;
329 free_out:
330 debugfs_remove_recursive(rcudir);
331 return 1;
334 static void __exit rcuclassic_trace_cleanup(void)
336 debugfs_remove_recursive(rcudir);
340 module_init(rcuclassic_trace_init);
341 module_exit(rcuclassic_trace_cleanup);
343 MODULE_AUTHOR("Paul E. McKenney");
344 MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
345 MODULE_LICENSE("GPL");