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 #include "rcutree.h"
  47
  48 static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
  49 {
  50         if (!rdp->beenonline)
  51                 return;
  52         seq_printf(m, "%3d%cc=%ld g=%ld pq=%d pqc=%ld qp=%d rpfq=%ld rp=%x",
  53                    rdp->cpu,
  54                    cpu_is_offline(rdp->cpu) ? '!' : ' ',
  55                    rdp->completed, rdp->gpnum,
  56                    rdp->passed_quiesc, rdp->passed_quiesc_completed,
  57                    rdp->qs_pending,
  58                    rdp->n_rcu_pending_force_qs - rdp->n_rcu_pending,
  59                    (int)(rdp->n_rcu_pending & 0xffff));
  60 #ifdef CONFIG_NO_HZ
  61         seq_printf(m, " dt=%d/%d dn=%d df=%lu",
  62                    rdp->dynticks->dynticks,
  63                    rdp->dynticks->dynticks_nesting,
  64                    rdp->dynticks->dynticks_nmi,
  65                    rdp->dynticks_fqs);
  66 #endif /* #ifdef CONFIG_NO_HZ */
  67         seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi);
  68         seq_printf(m, " ql=%ld b=%ld\n", rdp->qlen, rdp->blimit);
  69 }
  70
  71 #define PRINT_RCU_DATA(name, func, m) \
  72         do { \
  73                 int _p_r_d_i; \
  74                 \
  75                 for_each_possible_cpu(_p_r_d_i) \
  76                         func(m, &per_cpu(name, _p_r_d_i)); \
  77         } while (0)
  78
  79 static int show_rcudata(struct seq_file *m, void *unused)
  80 {
  81         seq_puts(m, "rcu:\n");
  82         PRINT_RCU_DATA(rcu_data, print_one_rcu_data, m);
  83         seq_puts(m, "rcu_bh:\n");
  84         PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data, m);
  85         return 0;
  86 }
  87
  88 static int rcudata_open(struct inode *inode, struct file *file)
  89 {
  90         return single_open(file, show_rcudata, NULL);
  91 }
  92
  93 static struct file_operations rcudata_fops = {
  94         .owner = THIS_MODULE,
  95         .open = rcudata_open,
  96         .read = seq_read,
  97         .llseek = seq_lseek,
  98         .release = single_release,
  99 };
 100
 101 static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
 102 {
 103         if (!rdp->beenonline)
 104                 return;
 105         seq_printf(m, "%d,%s,%ld,%ld,%d,%ld,%d,%ld,%ld",
 106                    rdp->cpu,
 107                    cpu_is_offline(rdp->cpu) ? "\"Y\"" : "\"N\"",
 108                    rdp->completed, rdp->gpnum,
 109                    rdp->passed_quiesc, rdp->passed_quiesc_completed,
 110                    rdp->qs_pending,
 111                    rdp->n_rcu_pending_force_qs - rdp->n_rcu_pending,
 112                    rdp->n_rcu_pending);
 113 #ifdef CONFIG_NO_HZ
 114         seq_printf(m, ",%d,%d,%d,%lu",
 115                    rdp->dynticks->dynticks,
 116                    rdp->dynticks->dynticks_nesting,
 117                    rdp->dynticks->dynticks_nmi,
 118                    rdp->dynticks_fqs);
 119 #endif /* #ifdef CONFIG_NO_HZ */
 120         seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
 121         seq_printf(m, ",%ld,%ld\n", rdp->qlen, rdp->blimit);
 122 }
 123
 124 static int show_rcudata_csv(struct seq_file *m, void *unused)
 125 {
 126         seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\",\"rpfq\",\"rp\",");
 127 #ifdef CONFIG_NO_HZ
 128         seq_puts(m, "\"dt\",\"dt nesting\",\"dn\",\"df\",");
 129 #endif /* #ifdef CONFIG_NO_HZ */
 130         seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\"\n");
 131         seq_puts(m, "\"rcu:\"\n");
 132         PRINT_RCU_DATA(rcu_data, print_one_rcu_data_csv, m);
 133         seq_puts(m, "\"rcu_bh:\"\n");
 134         PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data_csv, m);
 135         return 0;
 136 }
 137
 138 static int rcudata_csv_open(struct inode *inode, struct file *file)
 139 {
 140         return single_open(file, show_rcudata_csv, NULL);
 141 }
 142
 143 static struct file_operations rcudata_csv_fops = {
 144         .owner = THIS_MODULE,
 145         .open = rcudata_csv_open,
 146         .read = seq_read,
 147         .llseek = seq_lseek,
 148         .release = single_release,
 149 };
 150
 151 static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
 152 {
 153         int level = 0;
 154         struct rcu_node *rnp;
 155
 156         seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x "
 157                       "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
 158                    rsp->completed, rsp->gpnum, rsp->signaled,
 159                    (long)(rsp->jiffies_force_qs - jiffies),
 160                    (int)(jiffies & 0xffff),
 161                    rsp->n_force_qs, rsp->n_force_qs_ngp,
 162                    rsp->n_force_qs - rsp->n_force_qs_ngp,
 163                    rsp->n_force_qs_lh);
 164         for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
 165                 if (rnp->level != level) {
 166                         seq_puts(m, "\n");
 167                         level = rnp->level;
 168                 }
 169                 seq_printf(m, "%lx/%lx %d:%d ^%d    ",
 170                            rnp->qsmask, rnp->qsmaskinit,
 171                            rnp->grplo, rnp->grphi, rnp->grpnum);
 172         }
 173         seq_puts(m, "\n");
 174 }
 175
 176 static int show_rcuhier(struct seq_file *m, void *unused)
 177 {
 178         seq_puts(m, "rcu:\n");
 179         print_one_rcu_state(m, &rcu_state);
 180         seq_puts(m, "rcu_bh:\n");
 181         print_one_rcu_state(m, &rcu_bh_state);
 182         return 0;
 183 }
 184
 185 static int rcuhier_open(struct inode *inode, struct file *file)
 186 {
 187         return single_open(file, show_rcuhier, NULL);
 188 }
 189
 190 static struct file_operations rcuhier_fops = {
 191         .owner = THIS_MODULE,
 192         .open = rcuhier_open,
 193         .read = seq_read,
 194         .llseek = seq_lseek,
 195         .release = single_release,
 196 };
 197
 198 static int show_rcugp(struct seq_file *m, void *unused)
 199 {
 200         seq_printf(m, "rcu: completed=%ld  gpnum=%ld\n",
 201                    rcu_state.completed, rcu_state.gpnum);
 202         seq_printf(m, "rcu_bh: completed=%ld  gpnum=%ld\n",
 203                    rcu_bh_state.completed, rcu_bh_state.gpnum);
 204         return 0;
 205 }
 206
 207 static int rcugp_open(struct inode *inode, struct file *file)
 208 {
 209         return single_open(file, show_rcugp, NULL);
 210 }
 211
 212 static struct file_operations rcugp_fops = {
 213         .owner = THIS_MODULE,
 214         .open = rcugp_open,
 215         .read = seq_read,
 216         .llseek = seq_lseek,
 217         .release = single_release,
 218 };
 219
 220 static struct dentry *rcudir, *datadir, *datadir_csv, *hierdir, *gpdir;
 221 static int __init rcuclassic_trace_init(void)
 222 {
 223         rcudir = debugfs_create_dir("rcu", NULL);
 224         if (!rcudir)
 225                 goto out;
 226
 227         datadir = debugfs_create_file("rcudata", 0444, rcudir,
 228                                                 NULL, &rcudata_fops);
 229         if (!datadir)
 230                 goto free_out;
 231
 232         datadir_csv = debugfs_create_file("rcudata.csv", 0444, rcudir,
 233                                                 NULL, &rcudata_csv_fops);
 234         if (!datadir_csv)
 235                 goto free_out;
 236
 237         gpdir = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
 238         if (!gpdir)
 239                 goto free_out;
 240
 241         hierdir = debugfs_create_file("rcuhier", 0444, rcudir,
 242                                                 NULL, &rcuhier_fops);
 243         if (!hierdir)
 244                 goto free_out;
 245         return 0;
 246 free_out:
 247         if (datadir)
 248                 debugfs_remove(datadir);
 249         if (datadir_csv)
 250                 debugfs_remove(datadir_csv);
 251         if (gpdir)
 252                 debugfs_remove(gpdir);
 253         debugfs_remove(rcudir);
 254 out:
 255         return 1;
 256 }
 257
 258 static void __exit rcuclassic_trace_cleanup(void)
 259 {
 260         debugfs_remove(datadir);
 261         debugfs_remove(datadir_csv);
 262         debugfs_remove(gpdir);
 263         debugfs_remove(hierdir);
 264         debugfs_remove(rcudir);
 265 }
 266
 267
 268 module_init(rcuclassic_trace_init);
 269 module_exit(rcuclassic_trace_cleanup);
 270
 271 MODULE_AUTHOR("Paul E. McKenney");
 272 MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
 273 MODULE_LICENSE("GPL");