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