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