Paul E. McKenney | e260be6 | 2008-01-25 21:08:24 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Read-Copy Update tracing for realtime 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, 2006 |
| 19 | * |
| 20 | * Papers: http://www.rdrop.com/users/paulmck/RCU |
| 21 | * |
| 22 | * For detailed explanation of Read-Copy Update mechanism see - |
| 23 | * Documentation/RCU/ *.txt |
| 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> |
Paul E. McKenney | e260be6 | 2008-01-25 21:08:24 +0100 | [diff] [blame] | 41 | #include <linux/cpu.h> |
| 42 | #include <linux/mutex.h> |
| 43 | #include <linux/rcupreempt_trace.h> |
| 44 | #include <linux/debugfs.h> |
| 45 | |
| 46 | static struct mutex rcupreempt_trace_mutex; |
| 47 | static char *rcupreempt_trace_buf; |
| 48 | #define RCUPREEMPT_TRACE_BUF_SIZE 4096 |
| 49 | |
| 50 | void rcupreempt_trace_move2done(struct rcupreempt_trace *trace) |
| 51 | { |
| 52 | trace->done_length += trace->wait_length; |
| 53 | trace->done_add += trace->wait_length; |
| 54 | trace->wait_length = 0; |
| 55 | } |
| 56 | void rcupreempt_trace_move2wait(struct rcupreempt_trace *trace) |
| 57 | { |
| 58 | trace->wait_length += trace->next_length; |
| 59 | trace->wait_add += trace->next_length; |
| 60 | trace->next_length = 0; |
| 61 | } |
| 62 | void rcupreempt_trace_try_flip_1(struct rcupreempt_trace *trace) |
| 63 | { |
| 64 | atomic_inc(&trace->rcu_try_flip_1); |
| 65 | } |
| 66 | void rcupreempt_trace_try_flip_e1(struct rcupreempt_trace *trace) |
| 67 | { |
| 68 | atomic_inc(&trace->rcu_try_flip_e1); |
| 69 | } |
| 70 | void rcupreempt_trace_try_flip_i1(struct rcupreempt_trace *trace) |
| 71 | { |
| 72 | trace->rcu_try_flip_i1++; |
| 73 | } |
| 74 | void rcupreempt_trace_try_flip_ie1(struct rcupreempt_trace *trace) |
| 75 | { |
| 76 | trace->rcu_try_flip_ie1++; |
| 77 | } |
| 78 | void rcupreempt_trace_try_flip_g1(struct rcupreempt_trace *trace) |
| 79 | { |
| 80 | trace->rcu_try_flip_g1++; |
| 81 | } |
| 82 | void rcupreempt_trace_try_flip_a1(struct rcupreempt_trace *trace) |
| 83 | { |
| 84 | trace->rcu_try_flip_a1++; |
| 85 | } |
| 86 | void rcupreempt_trace_try_flip_ae1(struct rcupreempt_trace *trace) |
| 87 | { |
| 88 | trace->rcu_try_flip_ae1++; |
| 89 | } |
| 90 | void rcupreempt_trace_try_flip_a2(struct rcupreempt_trace *trace) |
| 91 | { |
| 92 | trace->rcu_try_flip_a2++; |
| 93 | } |
| 94 | void rcupreempt_trace_try_flip_z1(struct rcupreempt_trace *trace) |
| 95 | { |
| 96 | trace->rcu_try_flip_z1++; |
| 97 | } |
| 98 | void rcupreempt_trace_try_flip_ze1(struct rcupreempt_trace *trace) |
| 99 | { |
| 100 | trace->rcu_try_flip_ze1++; |
| 101 | } |
| 102 | void rcupreempt_trace_try_flip_z2(struct rcupreempt_trace *trace) |
| 103 | { |
| 104 | trace->rcu_try_flip_z2++; |
| 105 | } |
| 106 | void rcupreempt_trace_try_flip_m1(struct rcupreempt_trace *trace) |
| 107 | { |
| 108 | trace->rcu_try_flip_m1++; |
| 109 | } |
| 110 | void rcupreempt_trace_try_flip_me1(struct rcupreempt_trace *trace) |
| 111 | { |
| 112 | trace->rcu_try_flip_me1++; |
| 113 | } |
| 114 | void rcupreempt_trace_try_flip_m2(struct rcupreempt_trace *trace) |
| 115 | { |
| 116 | trace->rcu_try_flip_m2++; |
| 117 | } |
| 118 | void rcupreempt_trace_check_callbacks(struct rcupreempt_trace *trace) |
| 119 | { |
| 120 | trace->rcu_check_callbacks++; |
| 121 | } |
| 122 | void rcupreempt_trace_done_remove(struct rcupreempt_trace *trace) |
| 123 | { |
| 124 | trace->done_remove += trace->done_length; |
| 125 | trace->done_length = 0; |
| 126 | } |
| 127 | void rcupreempt_trace_invoke(struct rcupreempt_trace *trace) |
| 128 | { |
| 129 | atomic_inc(&trace->done_invoked); |
| 130 | } |
| 131 | void rcupreempt_trace_next_add(struct rcupreempt_trace *trace) |
| 132 | { |
| 133 | trace->next_add++; |
| 134 | trace->next_length++; |
| 135 | } |
| 136 | |
| 137 | static void rcupreempt_trace_sum(struct rcupreempt_trace *sp) |
| 138 | { |
| 139 | struct rcupreempt_trace *cp; |
| 140 | int cpu; |
| 141 | |
| 142 | memset(sp, 0, sizeof(*sp)); |
| 143 | for_each_possible_cpu(cpu) { |
| 144 | cp = rcupreempt_trace_cpu(cpu); |
| 145 | sp->next_length += cp->next_length; |
| 146 | sp->next_add += cp->next_add; |
| 147 | sp->wait_length += cp->wait_length; |
| 148 | sp->wait_add += cp->wait_add; |
| 149 | sp->done_length += cp->done_length; |
| 150 | sp->done_add += cp->done_add; |
| 151 | sp->done_remove += cp->done_remove; |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 152 | atomic_add(atomic_read(&cp->done_invoked), &sp->done_invoked); |
Paul E. McKenney | e260be6 | 2008-01-25 21:08:24 +0100 | [diff] [blame] | 153 | sp->rcu_check_callbacks += cp->rcu_check_callbacks; |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 154 | atomic_add(atomic_read(&cp->rcu_try_flip_1), |
| 155 | &sp->rcu_try_flip_1); |
| 156 | atomic_add(atomic_read(&cp->rcu_try_flip_e1), |
| 157 | &sp->rcu_try_flip_e1); |
Paul E. McKenney | e260be6 | 2008-01-25 21:08:24 +0100 | [diff] [blame] | 158 | sp->rcu_try_flip_i1 += cp->rcu_try_flip_i1; |
| 159 | sp->rcu_try_flip_ie1 += cp->rcu_try_flip_ie1; |
| 160 | sp->rcu_try_flip_g1 += cp->rcu_try_flip_g1; |
| 161 | sp->rcu_try_flip_a1 += cp->rcu_try_flip_a1; |
| 162 | sp->rcu_try_flip_ae1 += cp->rcu_try_flip_ae1; |
| 163 | sp->rcu_try_flip_a2 += cp->rcu_try_flip_a2; |
| 164 | sp->rcu_try_flip_z1 += cp->rcu_try_flip_z1; |
| 165 | sp->rcu_try_flip_ze1 += cp->rcu_try_flip_ze1; |
| 166 | sp->rcu_try_flip_z2 += cp->rcu_try_flip_z2; |
| 167 | sp->rcu_try_flip_m1 += cp->rcu_try_flip_m1; |
| 168 | sp->rcu_try_flip_me1 += cp->rcu_try_flip_me1; |
| 169 | sp->rcu_try_flip_m2 += cp->rcu_try_flip_m2; |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | static ssize_t rcustats_read(struct file *filp, char __user *buffer, |
| 174 | size_t count, loff_t *ppos) |
| 175 | { |
| 176 | struct rcupreempt_trace trace; |
| 177 | ssize_t bcount; |
| 178 | int cnt = 0; |
| 179 | |
| 180 | rcupreempt_trace_sum(&trace); |
| 181 | mutex_lock(&rcupreempt_trace_mutex); |
| 182 | snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, |
| 183 | "ggp=%ld rcc=%ld\n", |
| 184 | rcu_batches_completed(), |
| 185 | trace.rcu_check_callbacks); |
| 186 | snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, |
| 187 | "na=%ld nl=%ld wa=%ld wl=%ld da=%ld dl=%ld dr=%ld di=%d\n" |
| 188 | "1=%d e1=%d i1=%ld ie1=%ld g1=%ld a1=%ld ae1=%ld a2=%ld\n" |
| 189 | "z1=%ld ze1=%ld z2=%ld m1=%ld me1=%ld m2=%ld\n", |
| 190 | |
| 191 | trace.next_add, trace.next_length, |
| 192 | trace.wait_add, trace.wait_length, |
| 193 | trace.done_add, trace.done_length, |
| 194 | trace.done_remove, atomic_read(&trace.done_invoked), |
| 195 | atomic_read(&trace.rcu_try_flip_1), |
| 196 | atomic_read(&trace.rcu_try_flip_e1), |
| 197 | trace.rcu_try_flip_i1, trace.rcu_try_flip_ie1, |
| 198 | trace.rcu_try_flip_g1, |
| 199 | trace.rcu_try_flip_a1, trace.rcu_try_flip_ae1, |
| 200 | trace.rcu_try_flip_a2, |
| 201 | trace.rcu_try_flip_z1, trace.rcu_try_flip_ze1, |
| 202 | trace.rcu_try_flip_z2, |
| 203 | trace.rcu_try_flip_m1, trace.rcu_try_flip_me1, |
| 204 | trace.rcu_try_flip_m2); |
| 205 | bcount = simple_read_from_buffer(buffer, count, ppos, |
| 206 | rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); |
| 207 | mutex_unlock(&rcupreempt_trace_mutex); |
| 208 | return bcount; |
| 209 | } |
| 210 | |
| 211 | static ssize_t rcugp_read(struct file *filp, char __user *buffer, |
| 212 | size_t count, loff_t *ppos) |
| 213 | { |
| 214 | long oldgp = rcu_batches_completed(); |
| 215 | ssize_t bcount; |
| 216 | |
| 217 | mutex_lock(&rcupreempt_trace_mutex); |
| 218 | synchronize_rcu(); |
| 219 | snprintf(rcupreempt_trace_buf, RCUPREEMPT_TRACE_BUF_SIZE, |
| 220 | "oldggp=%ld newggp=%ld\n", oldgp, rcu_batches_completed()); |
| 221 | bcount = simple_read_from_buffer(buffer, count, ppos, |
| 222 | rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); |
| 223 | mutex_unlock(&rcupreempt_trace_mutex); |
| 224 | return bcount; |
| 225 | } |
| 226 | |
| 227 | static ssize_t rcuctrs_read(struct file *filp, char __user *buffer, |
| 228 | size_t count, loff_t *ppos) |
| 229 | { |
| 230 | int cnt = 0; |
| 231 | int cpu; |
| 232 | int f = rcu_batches_completed() & 0x1; |
| 233 | ssize_t bcount; |
| 234 | |
| 235 | mutex_lock(&rcupreempt_trace_mutex); |
| 236 | |
| 237 | cnt += snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE, |
| 238 | "CPU last cur F M\n"); |
| 239 | for_each_online_cpu(cpu) { |
| 240 | long *flipctr = rcupreempt_flipctr(cpu); |
| 241 | cnt += snprintf(&rcupreempt_trace_buf[cnt], |
| 242 | RCUPREEMPT_TRACE_BUF_SIZE - cnt, |
| 243 | "%3d %4ld %3ld %d %d\n", |
| 244 | cpu, |
| 245 | flipctr[!f], |
| 246 | flipctr[f], |
| 247 | rcupreempt_flip_flag(cpu), |
| 248 | rcupreempt_mb_flag(cpu)); |
| 249 | } |
| 250 | cnt += snprintf(&rcupreempt_trace_buf[cnt], |
| 251 | RCUPREEMPT_TRACE_BUF_SIZE - cnt, |
| 252 | "ggp = %ld, state = %s\n", |
| 253 | rcu_batches_completed(), |
| 254 | rcupreempt_try_flip_state_name()); |
| 255 | cnt += snprintf(&rcupreempt_trace_buf[cnt], |
| 256 | RCUPREEMPT_TRACE_BUF_SIZE - cnt, |
| 257 | "\n"); |
| 258 | bcount = simple_read_from_buffer(buffer, count, ppos, |
| 259 | rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); |
| 260 | mutex_unlock(&rcupreempt_trace_mutex); |
| 261 | return bcount; |
| 262 | } |
| 263 | |
| 264 | static struct file_operations rcustats_fops = { |
| 265 | .owner = THIS_MODULE, |
| 266 | .read = rcustats_read, |
| 267 | }; |
| 268 | |
| 269 | static struct file_operations rcugp_fops = { |
| 270 | .owner = THIS_MODULE, |
| 271 | .read = rcugp_read, |
| 272 | }; |
| 273 | |
| 274 | static struct file_operations rcuctrs_fops = { |
| 275 | .owner = THIS_MODULE, |
| 276 | .read = rcuctrs_read, |
| 277 | }; |
| 278 | |
| 279 | static struct dentry *rcudir, *statdir, *ctrsdir, *gpdir; |
| 280 | static int rcupreempt_debugfs_init(void) |
| 281 | { |
| 282 | rcudir = debugfs_create_dir("rcu", NULL); |
| 283 | if (!rcudir) |
| 284 | goto out; |
| 285 | statdir = debugfs_create_file("rcustats", 0444, rcudir, |
| 286 | NULL, &rcustats_fops); |
| 287 | if (!statdir) |
| 288 | goto free_out; |
| 289 | |
| 290 | gpdir = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops); |
| 291 | if (!gpdir) |
| 292 | goto free_out; |
| 293 | |
| 294 | ctrsdir = debugfs_create_file("rcuctrs", 0444, rcudir, |
| 295 | NULL, &rcuctrs_fops); |
| 296 | if (!ctrsdir) |
| 297 | goto free_out; |
| 298 | return 0; |
| 299 | free_out: |
| 300 | if (statdir) |
| 301 | debugfs_remove(statdir); |
| 302 | if (gpdir) |
| 303 | debugfs_remove(gpdir); |
| 304 | debugfs_remove(rcudir); |
| 305 | out: |
| 306 | return 1; |
| 307 | } |
| 308 | |
| 309 | static int __init rcupreempt_trace_init(void) |
| 310 | { |
Steven Rostedt | 5802294 | 2008-07-30 14:20:55 -0400 | [diff] [blame] | 311 | int ret; |
| 312 | |
Paul E. McKenney | e260be6 | 2008-01-25 21:08:24 +0100 | [diff] [blame] | 313 | mutex_init(&rcupreempt_trace_mutex); |
| 314 | rcupreempt_trace_buf = kmalloc(RCUPREEMPT_TRACE_BUF_SIZE, GFP_KERNEL); |
| 315 | if (!rcupreempt_trace_buf) |
| 316 | return 1; |
Steven Rostedt | 5802294 | 2008-07-30 14:20:55 -0400 | [diff] [blame] | 317 | ret = rcupreempt_debugfs_init(); |
| 318 | if (ret) |
| 319 | kfree(rcupreempt_trace_buf); |
| 320 | return ret; |
Paul E. McKenney | e260be6 | 2008-01-25 21:08:24 +0100 | [diff] [blame] | 321 | } |
| 322 | |
| 323 | static void __exit rcupreempt_trace_cleanup(void) |
| 324 | { |
| 325 | debugfs_remove(statdir); |
| 326 | debugfs_remove(gpdir); |
| 327 | debugfs_remove(ctrsdir); |
| 328 | debugfs_remove(rcudir); |
| 329 | kfree(rcupreempt_trace_buf); |
| 330 | } |
| 331 | |
| 332 | |
| 333 | module_init(rcupreempt_trace_init); |
| 334 | module_exit(rcupreempt_trace_cleanup); |