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: releng/5.0/sys/kern/subr_devstat.c 105354 2002-10-17 20:03:38Z robert $
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");
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