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 *
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28 * $FreeBSD: head/sys/kern/subr_devstat.c 62454 2000-07-03 09:35:31Z phk $
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28 * $FreeBSD: head/sys/kern/subr_devstat.c 62573 2000-07-04 11:25:35Z phk $ |
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 39static int devstat_num_devs; 40static long devstat_generation; 41static int devstat_version = DEVSTAT_VERSION; 42static int devstat_current_devnumber; 43 44static STAILQ_HEAD(devstatlist, devstat) 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 */ 50void 51devstat_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 for (ds_tmp = STAILQ_FIRST(devstat_head); ds_tmp != NULL; 84 ds_tmp = STAILQ_NEXT(ds_tmp, dev_links)) { 85 struct devstat *ds_next; 86 87 ds_next = STAILQ_NEXT(ds_tmp, dev_links); 88 89 /* 90 * If we find a break between higher and lower 91 * priority items, and if this item fits in the 92 * break, insert it. This also applies if the 93 * "lower priority item" is the end of the list. 94 */ 95 if ((priority <= ds_tmp->priority) 96 && ((ds_next == NULL) 97 || (priority > ds_next->priority))) { 98 STAILQ_INSERT_AFTER(devstat_head, ds_tmp, ds, 99 dev_links); 100 break; 101 } else if (priority > ds_tmp->priority) { 102 /* 103 * If this is the case, we should be able 104 * to insert ourselves at the head of the 105 * list. If we can't, something is wrong. 106 */ 107 if (ds_tmp == STAILQ_FIRST(devstat_head)) { 108 STAILQ_INSERT_HEAD(devstat_head, 109 ds, dev_links); 110 break; 111 } else { 112 STAILQ_INSERT_TAIL(devstat_head, 113 ds, dev_links); 114 printf("devstat_add_entry: HELP! " 115 "sorting problem detected " 116 "for %s%d\n", dev_name, 117 unit_number); 118 break; 119 } 120 } 121 } 122 } 123 124 ds->device_number = devstat_current_devnumber++; 125 ds->unit_number = unit_number; 126 strncpy(ds->device_name, dev_name, DEVSTAT_NAME_LEN); 127 ds->device_name[DEVSTAT_NAME_LEN - 1] = '\0'; 128 ds->block_size = block_size; 129 ds->flags = flags; 130 ds->device_type = device_type; 131 ds->priority = priority; 132 getmicrotime(&ds->dev_creation_time); 133} 134 135/* 136 * Remove a devstat structure from the list of devices. 137 */ 138void 139devstat_remove_entry(struct devstat *ds) 140{ 141 struct devstatlist *devstat_head; 142 143 if (ds == NULL) 144 return; 145 146 devstat_generation++; 147 devstat_num_devs--; 148 149 devstat_head = &device_statq; 150 151 /* Remove this entry from the devstat queue */ 152 STAILQ_REMOVE(devstat_head, ds, devstat, dev_links); 153} 154 155/* 156 * Record a transaction start. 157 */ 158void 159devstat_start_transaction(struct devstat *ds) 160{ 161 /* sanity check */ 162 if (ds == NULL) 163 return; 164 165 /* 166 * We only want to set the start time when we are going from idle 167 * to busy. The start time is really the start of the latest busy 168 * period. 169 */ 170 if (ds->busy_count == 0) 171 getmicrouptime(&ds->start_time); 172 ds->busy_count++; 173} 174 175/* 176 * Record the ending of a transaction, and incrment the various counters. 177 */ 178void 179devstat_end_transaction(struct devstat *ds, u_int32_t bytes, 180 devstat_tag_type tag_type, devstat_trans_flags flags) 181{ 182 struct timeval busy_time; 183 184 /* sanity check */ 185 if (ds == NULL) 186 return; 187 188 getmicrouptime(&ds->last_comp_time); 189 ds->busy_count--; 190 191 /* 192 * There might be some transactions (DEVSTAT_NO_DATA) that don't 193 * transfer any data. 194 */ 195 if (flags == DEVSTAT_READ) { 196 ds->bytes_read += bytes; 197 ds->num_reads++; 198 } else if (flags == DEVSTAT_WRITE) { 199 ds->bytes_written += bytes; 200 ds->num_writes++; 201 } else if (flags == DEVSTAT_FREE) { 202 ds->bytes_freed += bytes; 203 ds->num_frees++; 204 } else 205 ds->num_other++; 206 207 /* 208 * Keep a count of the various tag types sent. 209 */ 210 if ((ds->flags & DEVSTAT_NO_ORDERED_TAGS) == 0 && 211 tag_type != DEVSTAT_TAG_NONE) 212 ds->tag_types[tag_type]++; 213 214 /* 215 * We only update the busy time when we go idle. Otherwise, this 216 * calculation would require many more clock cycles. 217 */ 218 if (ds->busy_count == 0) { 219 /* Calculate how long we were busy */ 220 busy_time = ds->last_comp_time; 221 timevalsub(&busy_time, &ds->start_time); 222 223 /* Add our busy time to the total busy time. */ 224 timevaladd(&ds->busy_time, &busy_time); 225 } else if (ds->busy_count < 0) 226 printf("devstat_end_transaction: HELP!! busy_count " 227 "for %s%d is < 0 (%d)!\n", ds->device_name, 228 ds->unit_number, ds->busy_count); 229} 230 231void 232devstat_end_transaction_bio(struct devstat *ds, struct bio *bp) 233{ 234 devstat_trans_flags flg; 235 236 if (bp->bio_cmd == BIO_DELETE) 237 flg = DEVSTAT_FREE; 238 else if (bp->bio_cmd == BIO_READ) 239 flg = DEVSTAT_READ; 240 else 241 flg = DEVSTAT_WRITE; 242 243 devstat_end_transaction(ds, bp->bio_bcount - bp->bio_resid, 244 (bp->bio_flags & BIO_ORDERED) ? 245 DEVSTAT_TAG_ORDERED : DEVSTAT_TAG_SIMPLE, flg); 246} 247 248/* 249 * This is the sysctl handler for the devstat package. The data pushed out 250 * on the kern.devstat.all sysctl variable consists of the current devstat 251 * generation number, and then an array of devstat structures, one for each 252 * device in the system. 253 * 254 * I'm really not too fond of this method of doing things, but there really 255 * aren't that many alternatives. We must have some method of making sure 256 * that the generation number the user gets corresponds with the data the 257 * user gets. If the user makes a separate sysctl call to get the 258 * generation, and then a sysctl call to get the device statistics, the 259 * device list could have changed in that brief period of time. By 260 * supplying the generation number along with the statistics output, we can 261 * guarantee that the generation number and the statistics match up. 262 */ 263static int
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264sysctl_devstat (SYSCTL_HANDLER_ARGS)
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264sysctl_devstat(SYSCTL_HANDLER_ARGS) |
265{ 266 int error, i; 267 struct devstat *nds; 268 struct devstatlist *devstat_head; 269 270 if (devstat_num_devs == 0) 271 return(EINVAL); 272 273 error = 0; 274 devstat_head = &device_statq; 275 276 /* 277 * First push out the generation number. 278 */ 279 error = SYSCTL_OUT(req, &devstat_generation, sizeof(long)); 280 281 /* 282 * Now push out all the devices. 283 */ 284 for (i = 0, nds = STAILQ_FIRST(devstat_head); 285 (nds != NULL) && (i < devstat_num_devs) && (error == 0); 286 nds = STAILQ_NEXT(nds, dev_links), i++) 287 error = SYSCTL_OUT(req, nds, sizeof(struct devstat)); 288 289 return(error); 290} 291 292/* 293 * Sysctl entries for devstat. The first one is a node that all the rest 294 * hang off of. 295 */ 296SYSCTL_NODE(_kern, OID_AUTO, devstat, CTLFLAG_RD, 0, "Device Statistics"); 297 298SYSCTL_PROC(_kern_devstat, OID_AUTO, all, CTLFLAG_RD|CTLTYPE_OPAQUE, 299 0, 0, sysctl_devstat, "S,devstat", "All devices in the devstat list"); 300/* 301 * Export the number of devices in the system so that userland utilities 302 * can determine how much memory to allocate to hold all the devices. 303 */ 304SYSCTL_INT(_kern_devstat, OID_AUTO, numdevs, CTLFLAG_RD, 305 &devstat_num_devs, 0, "Number of devices in the devstat list"); 306SYSCTL_LONG(_kern_devstat, OID_AUTO, generation, CTLFLAG_RD, 307 &devstat_generation, "Devstat list generation"); 308SYSCTL_INT(_kern_devstat, OID_AUTO, version, CTLFLAG_RD, 309 &devstat_version, 0, "Devstat list version number");
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