1 /* 2 * Copyright (c) 1997, 1998, 1999 Kenneth D. Merry. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/kernel.h> 33 #include <sys/systm.h> 34 #include <sys/bio.h> 35 #include <sys/sysctl.h> 36 37 #include <sys/devicestat.h> 38 39 static int devstat_num_devs; 40 static long devstat_generation; 41 static int devstat_version = DEVSTAT_VERSION; 42 static int devstat_current_devnumber; 43 44 static struct devstatlist device_statq; 45 46 /* 47 * Take a malloced and zeroed devstat structure given to us, fill it in 48 * and add it to the queue of devices. 49 */ 50 void 51 devstat_add_entry(struct devstat *ds, const char *dev_name, 52 int unit_number, u_int32_t block_size, 53 devstat_support_flags flags, 54 devstat_type_flags device_type, 55 devstat_priority priority) 56 { 57 struct devstatlist *devstat_head; 58 struct devstat *ds_tmp; 59 60 if (ds == NULL) 61 return; 62 63 if (devstat_num_devs == 0) 64 STAILQ_INIT(&device_statq); 65 66 devstat_generation++; 67 devstat_num_devs++; 68 69 devstat_head = &device_statq; 70 71 /* 72 * Priority sort. Each driver passes in its priority when it adds 73 * its devstat entry. Drivers are sorted first by priority, and 74 * then by probe order. 75 * 76 * For the first device, we just insert it, since the priority 77 * doesn't really matter yet. Subsequent devices are inserted into 78 * the list using the order outlined above. 79 */ 80 if (devstat_num_devs == 1) 81 STAILQ_INSERT_TAIL(devstat_head, ds, dev_links); 82 else { 83 STAILQ_FOREACH(ds_tmp, devstat_head, dev_links) { 84 struct devstat *ds_next; 85 86 ds_next = STAILQ_NEXT(ds_tmp, dev_links); 87 88 /* 89 * If we find a break between higher and lower 90 * priority items, and if this item fits in the 91 * break, insert it. This also applies if the 92 * "lower priority item" is the end of the list. 93 */ 94 if ((priority <= ds_tmp->priority) 95 && ((ds_next == NULL) 96 || (priority > ds_next->priority))) { 97 STAILQ_INSERT_AFTER(devstat_head, ds_tmp, ds, 98 dev_links); 99 break; 100 } else if (priority > ds_tmp->priority) { 101 /* 102 * If this is the case, we should be able 103 * to insert ourselves at the head of the 104 * list. If we can't, something is wrong. 105 */ 106 if (ds_tmp == STAILQ_FIRST(devstat_head)) { 107 STAILQ_INSERT_HEAD(devstat_head, 108 ds, dev_links); 109 break; 110 } else { 111 STAILQ_INSERT_TAIL(devstat_head, 112 ds, dev_links); 113 printf("devstat_add_entry: HELP! " 114 "sorting problem detected " 115 "for %s%d\n", dev_name, 116 unit_number); 117 break; 118 } 119 } 120 } 121 } 122 123 ds->device_number = devstat_current_devnumber++; 124 ds->unit_number = unit_number; 125 strlcpy(ds->device_name, dev_name, DEVSTAT_NAME_LEN); 126 ds->block_size = block_size; 127 ds->flags = flags; 128 ds->device_type = device_type; 129 ds->priority = priority; 130 getmicrotime(&ds->dev_creation_time); 131 } 132 133 /* 134 * Remove a devstat structure from the list of devices. 135 */ 136 void 137 devstat_remove_entry(struct devstat *ds) 138 { 139 struct devstatlist *devstat_head; 140 141 if (ds == NULL) 142 return; 143 144 devstat_generation++; 145 devstat_num_devs--; 146 147 devstat_head = &device_statq; 148 149 /* Remove this entry from the devstat queue */ 150 STAILQ_REMOVE(devstat_head, ds, devstat, dev_links); 151 } 152 153 /* 154 * Record a transaction start. 155 */ 156 void 157 devstat_start_transaction(struct devstat *ds) 158 { 159 /* sanity check */ 160 if (ds == NULL) 161 return; 162 163 /* 164 * We only want to set the start time when we are going from idle 165 * to busy. The start time is really the start of the latest busy 166 * period. 167 */ 168 if (ds->busy_count == 0) 169 getmicrouptime(&ds->start_time); 170 ds->busy_count++; 171 } 172 173 /* 174 * Record the ending of a transaction, and incrment the various counters. 175 */ 176 void 177 devstat_end_transaction(struct devstat *ds, u_int32_t bytes, 178 devstat_tag_type tag_type, devstat_trans_flags flags) 179 { 180 struct timeval busy_time; 181 182 /* sanity check */ 183 if (ds == NULL) 184 return; 185 186 getmicrouptime(&ds->last_comp_time); 187 ds->busy_count--; 188 189 /* 190 * There might be some transactions (DEVSTAT_NO_DATA) that don't 191 * transfer any data. 192 */ 193 if (flags == DEVSTAT_READ) { 194 ds->bytes_read += bytes; 195 ds->num_reads++; 196 } else if (flags == DEVSTAT_WRITE) { 197 ds->bytes_written += bytes; 198 ds->num_writes++; 199 } else if (flags == DEVSTAT_FREE) { 200 ds->bytes_freed += bytes; 201 ds->num_frees++; 202 } else 203 ds->num_other++; 204 205 /* 206 * Keep a count of the various tag types sent. 207 */ 208 if ((ds->flags & DEVSTAT_NO_ORDERED_TAGS) == 0 && 209 tag_type != DEVSTAT_TAG_NONE) 210 ds->tag_types[tag_type]++; 211 212 /* 213 * We only update the busy time when we go idle. Otherwise, this 214 * calculation would require many more clock cycles. 215 */ 216 if (ds->busy_count == 0) { 217 /* Calculate how long we were busy */ 218 busy_time = ds->last_comp_time; 219 timevalsub(&busy_time, &ds->start_time); 220 221 /* Add our busy time to the total busy time. */ 222 timevaladd(&ds->busy_time, &busy_time); 223 } else if (ds->busy_count < 0) 224 printf("devstat_end_transaction: HELP!! busy_count " 225 "for %s%d is < 0 (%d)!\n", ds->device_name, 226 ds->unit_number, ds->busy_count); 227 } 228 229 void 230 devstat_end_transaction_bio(struct devstat *ds, struct bio *bp) 231 { 232 devstat_trans_flags flg; 233 234 if (bp->bio_cmd == BIO_DELETE) 235 flg = DEVSTAT_FREE; 236 else if (bp->bio_cmd == BIO_READ) 237 flg = DEVSTAT_READ; 238 else 239 flg = DEVSTAT_WRITE; 240 241 devstat_end_transaction(ds, bp->bio_bcount - bp->bio_resid, 242 DEVSTAT_TAG_SIMPLE, flg); 243 } 244 245 /* 246 * This is the sysctl handler for the devstat package. The data pushed out 247 * on the kern.devstat.all sysctl variable consists of the current devstat 248 * generation number, and then an array of devstat structures, one for each 249 * device in the system. 250 * 251 * I'm really not too fond of this method of doing things, but there really 252 * aren't that many alternatives. We must have some method of making sure 253 * that the generation number the user gets corresponds with the data the 254 * user gets. If the user makes a separate sysctl call to get the 255 * generation, and then a sysctl call to get the device statistics, the 256 * device list could have changed in that brief period of time. By 257 * supplying the generation number along with the statistics output, we can 258 * guarantee that the generation number and the statistics match up. 259 */ 260 static int 261 sysctl_devstat(SYSCTL_HANDLER_ARGS) 262 { 263 int error, i; 264 struct devstat *nds; 265 struct devstatlist *devstat_head; 266 267 if (devstat_num_devs == 0) 268 return(EINVAL); 269 270 error = 0; 271 devstat_head = &device_statq; 272 273 /* 274 * First push out the generation number. 275 */ 276 error = SYSCTL_OUT(req, &devstat_generation, sizeof(long)); 277 278 /* 279 * Now push out all the devices. 280 */ 281 for (i = 0, nds = STAILQ_FIRST(devstat_head); 282 (nds != NULL) && (i < devstat_num_devs) && (error == 0); 283 nds = STAILQ_NEXT(nds, dev_links), i++) 284 error = SYSCTL_OUT(req, nds, sizeof(struct devstat)); 285 286 return(error); 287 } 288 289 /* 290 * Sysctl entries for devstat. The first one is a node that all the rest 291 * hang off of. 292 */ 293 SYSCTL_NODE(_kern, OID_AUTO, devstat, CTLFLAG_RD, 0, "Device Statistics"); 294 295 SYSCTL_PROC(_kern_devstat, OID_AUTO, all, CTLFLAG_RD|CTLTYPE_OPAQUE, 296 0, 0, sysctl_devstat, "S,devstat", "All devices in the devstat list"); 297 /* 298 * Export the number of devices in the system so that userland utilities 299 * can determine how much memory to allocate to hold all the devices. 300 */ 301 SYSCTL_INT(_kern_devstat, OID_AUTO, numdevs, CTLFLAG_RD, 302 &devstat_num_devs, 0, "Number of devices in the devstat list"); 303 SYSCTL_LONG(_kern_devstat, OID_AUTO, generation, CTLFLAG_RD, 304 &devstat_generation, 0, "Devstat list generation"); 305 SYSCTL_INT(_kern_devstat, OID_AUTO, version, CTLFLAG_RD, 306 &devstat_version, 0, "Devstat list version number"); 307