1 /* $NetBSD: subr_iostat.c,v 1.26 2024/05/04 13:33:18 mlelstv Exp $ */
2 /* NetBSD: subr_disk.c,v 1.69 2005/05/29 22:24:15 christos Exp */
3
4 /*-
5 * Copyright (c) 1996, 1997, 1999, 2000, 2009 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
10 * NASA Ames Research Center.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 /*
35 * Copyright (c) 1982, 1986, 1988, 1993
36 * The Regents of the University of California. All rights reserved.
37 * (c) UNIX System Laboratories, Inc.
38 * All or some portions of this file are derived from material licensed
39 * to the University of California by American Telephone and Telegraph
40 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
41 * the permission of UNIX System Laboratories, Inc.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 * notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 * notice, this list of conditions and the following disclaimer in the
50 * documentation and/or other materials provided with the distribution.
51 * 3. Neither the name of the University nor the names of its contributors
52 * may be used to endorse or promote products derived from this software
53 * without specific prior written permission.
54 *
55 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65 * SUCH DAMAGE.
66 *
67 * @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94
68 */
69
70 #include <sys/cdefs.h>
71 __KERNEL_RCSID(0, "$NetBSD: subr_iostat.c,v 1.26 2024/05/04 13:33:18 mlelstv Exp $");
72
73 #include <sys/param.h>
74 #include <sys/kernel.h>
75 #include <sys/kmem.h>
76 #include <sys/iostat.h>
77 #include <sys/sysctl.h>
78 #include <sys/rwlock.h>
79
80 /*
81 * Function prototypes for sysctl nodes
82 */
83 static int sysctl_hw_disknames(SYSCTLFN_PROTO);
84 static int sysctl_hw_iostatnames(SYSCTLFN_PROTO);
85 static int sysctl_hw_iostats(SYSCTLFN_PROTO);
86
87 static int
88 iostati_getnames(int disk_only, char *oldp, size_t *oldlenp, const void *newp,
89 u_int namelen);
90
91 /*
92 * A global list of all drives attached to the system. May grow or
93 * shrink over time.
94 */
95 struct iostatlist_head iostatlist = TAILQ_HEAD_INITIALIZER(iostatlist);
96 int iostat_count; /* number of drives in global drivelist */
97 krwlock_t iostatlist_lock;
98
99 static void sysctl_io_stats_setup(struct sysctllog **);
100
101 /*
102 * Initialise the iostat subsystem.
103 */
104 void
iostat_init(void)105 iostat_init(void)
106 {
107
108 rw_init(&iostatlist_lock);
109 sysctl_io_stats_setup(NULL);
110 }
111
112 /*
113 * Searches the iostatlist for the iostat corresponding to the
114 * name provided.
115 */
116 struct io_stats *
iostat_find(const char * name)117 iostat_find(const char *name)
118 {
119 struct io_stats *iostatp;
120
121 KASSERT(name != NULL);
122
123 rw_enter(&iostatlist_lock, RW_READER);
124 TAILQ_FOREACH(iostatp, &iostatlist, io_link) {
125 if (strcmp(iostatp->io_name, name) == 0) {
126 break;
127 }
128 }
129 rw_exit(&iostatlist_lock);
130
131 return iostatp;
132 }
133
134 /*
135 * Allocate and initialise memory for the i/o statistics.
136 */
137 struct io_stats *
iostat_alloc(int32_t type,void * parent,const char * name)138 iostat_alloc(int32_t type, void *parent, const char *name)
139 {
140 struct io_stats *stats;
141
142 stats = kmem_zalloc(sizeof(*stats), KM_SLEEP);
143 stats->io_type = type;
144 stats->io_parent = parent;
145 (void)strlcpy(stats->io_name, name, sizeof(stats->io_name));
146
147 /*
148 * Set the attached timestamp.
149 */
150 getmicrouptime(&stats->io_attachtime);
151
152 /*
153 * Link into the drivelist.
154 */
155 rw_enter(&iostatlist_lock, RW_WRITER);
156 TAILQ_INSERT_TAIL(&iostatlist, stats, io_link);
157 iostat_count++;
158 rw_exit(&iostatlist_lock);
159
160 return stats;
161 }
162
163 /*
164 * Remove i/o from stats collection.
165 */
166 void
iostat_free(struct io_stats * stats)167 iostat_free(struct io_stats *stats)
168 {
169
170 /*
171 * Remove from the iostat list.
172 */
173 if (iostat_count == 0)
174 panic("iostat_free: iostat_count == 0");
175 rw_enter(&iostatlist_lock, RW_WRITER);
176 TAILQ_REMOVE(&iostatlist, stats, io_link);
177 iostat_count--;
178 rw_exit(&iostatlist_lock);
179 kmem_free(stats, sizeof(*stats));
180 }
181
182 /*
183 * Rename i/o stats.
184 */
185 void
iostat_rename(struct io_stats * stats,const char * name)186 iostat_rename(struct io_stats *stats, const char *name)
187 {
188
189 rw_enter(&iostatlist_lock, RW_WRITER);
190 (void)strlcpy(stats->io_name, name, sizeof(stats->io_name));
191 rw_exit(&iostatlist_lock);
192 }
193
194 /*
195 * multiply timeval by unsigned integer and add to result
196 */
197 static void
timermac(struct timeval * a,uint64_t count,struct timeval * res)198 timermac(struct timeval *a, uint64_t count, struct timeval *res)
199 {
200 struct timeval part = *a;
201
202 while (count) {
203 if (count & 1)
204 timeradd(res, &part, res);
205 timeradd(&part, &part, &part);
206 count >>= 1;
207 }
208 }
209
210 /*
211 * Increment the iostat wait counter.
212 * Accumulate wait time and timesum.
213 *
214 * Wait time is spent in the device bufq.
215 */
216 void
iostat_wait(struct io_stats * stats)217 iostat_wait(struct io_stats *stats)
218 {
219 struct timeval dv_time, diff_time;
220 int32_t count;
221
222 KASSERT(stats->io_wait >= 0);
223
224 getmicrouptime(&dv_time);
225
226 timersub(&dv_time, &stats->io_waitstamp, &diff_time);
227 count = stats->io_wait++;
228 if (count != 0) {
229 timermac(&diff_time, count, &stats->io_waitsum);
230 timeradd(&stats->io_waittime, &diff_time, &stats->io_waittime);
231 }
232 stats->io_waitstamp = dv_time;
233 }
234
235 /*
236 * Decrement the iostat wait counter.
237 * Increment the iostat busy counter.
238 * Accumulate wait and busy times and timesums.
239 *
240 * Busy time is spent being processed by the device.
241 *
242 * Old devices do not yet measure wait time, so skip
243 * processing it if the counter is still zero.
244 */
245 void
iostat_busy(struct io_stats * stats)246 iostat_busy(struct io_stats *stats)
247 {
248 struct timeval dv_time, diff_time;
249 int32_t count;
250
251 KASSERT(stats->io_wait >= 0); /* > 0 when iostat_wait is used */
252 KASSERT(stats->io_busy >= 0);
253
254 getmicrouptime(&dv_time);
255
256 timersub(&dv_time, &stats->io_waitstamp, &diff_time);
257 if (stats->io_wait != 0) {
258 count = stats->io_wait--;
259 timermac(&diff_time, count, &stats->io_waitsum);
260 timeradd(&stats->io_waittime, &diff_time, &stats->io_waittime);
261 }
262 stats->io_waitstamp = dv_time;
263
264 timersub(&dv_time, &stats->io_busystamp, &diff_time);
265 count = stats->io_busy++;
266 if (count != 0) {
267 timermac(&diff_time, count, &stats->io_busysum);
268 timeradd(&stats->io_busytime, &diff_time, &stats->io_busytime);
269 }
270 stats->io_busystamp = dv_time;
271 }
272
273 /*
274 * Decrement the iostat busy counter, increment the byte count.
275 * Accumulate busy time and timesum.
276 */
277 void
iostat_unbusy(struct io_stats * stats,long bcount,int read)278 iostat_unbusy(struct io_stats *stats, long bcount, int read)
279 {
280 struct timeval dv_time, diff_time;
281 int32_t count;
282
283 KASSERT(stats->io_busy > 0);
284
285 getmicrouptime(&dv_time);
286 stats->io_timestamp = dv_time;
287
288 /* any op */
289 timersub(&dv_time, &stats->io_busystamp, &diff_time);
290 count = stats->io_busy--;
291 timermac(&diff_time, count, &stats->io_busysum);
292 timeradd(&stats->io_busytime, &diff_time, &stats->io_busytime);
293 stats->io_busystamp = dv_time;
294
295 if (bcount > 0) {
296 if (read) {
297 stats->io_rbytes += bcount;
298 stats->io_rxfer++;
299 } else {
300 stats->io_wbytes += bcount;
301 stats->io_wxfer++;
302 }
303 }
304 }
305
306 /*
307 * Return non-zero if a device has an I/O request in flight.
308 */
309 bool
iostat_isbusy(struct io_stats * stats)310 iostat_isbusy(struct io_stats *stats)
311 {
312
313 return stats->io_busy != 0;
314 }
315
316 /*
317 * Increment the seek counter. This does look almost redundant but it
318 * abstracts the stats gathering.
319 */
320 void
iostat_seek(struct io_stats * stats)321 iostat_seek(struct io_stats *stats)
322 {
323
324 stats->io_seek++;
325 }
326
327 static int
sysctl_hw_disknames(SYSCTLFN_ARGS)328 sysctl_hw_disknames(SYSCTLFN_ARGS)
329 {
330
331 return iostati_getnames(1, oldp, oldlenp, newp, namelen);
332 }
333
334 static int
sysctl_hw_iostatnames(SYSCTLFN_ARGS)335 sysctl_hw_iostatnames(SYSCTLFN_ARGS)
336 {
337
338 return iostati_getnames(0, oldp, oldlenp, newp, namelen);
339 }
340
341 static int
iostati_getnames(int disk_only,char * oldp,size_t * oldlenp,const void * newp,u_int namelen)342 iostati_getnames(int disk_only, char *oldp, size_t *oldlenp, const void *newp,
343 u_int namelen)
344 {
345 char bf[IOSTATNAMELEN + 1];
346 char *where = oldp;
347 struct io_stats *stats;
348 size_t needed, left, slen;
349 int error, first;
350
351 if (newp != NULL)
352 return (EPERM);
353 if (namelen != 0)
354 return (EINVAL);
355
356 first = 1;
357 error = 0;
358 needed = 0;
359 left = *oldlenp;
360
361 rw_enter(&iostatlist_lock, RW_READER);
362 for (stats = TAILQ_FIRST(&iostatlist); stats != NULL;
363 stats = TAILQ_NEXT(stats, io_link)) {
364 if ((disk_only == 1) && (stats->io_type != IOSTAT_DISK))
365 continue;
366
367 if (where == NULL)
368 needed += strlen(stats->io_name) + 1;
369 else {
370 memset(bf, 0, sizeof(bf));
371 if (first) {
372 strncpy(bf, stats->io_name, sizeof(bf));
373 /* account for trailing NUL byte */
374 needed += 1;
375 first = 0;
376 } else {
377 bf[0] = ' ';
378 strncpy(bf + 1, stats->io_name,
379 sizeof(bf) - 1);
380 }
381 bf[IOSTATNAMELEN] = '\0';
382 slen = strlen(bf);
383 if (left < slen + 1)
384 break;
385 /* +1 to copy out the trailing NUL byte */
386 error = copyout(bf, where, slen + 1);
387 if (error)
388 break;
389 where += slen;
390 needed += slen;
391 left -= slen;
392 }
393 }
394 rw_exit(&iostatlist_lock);
395 *oldlenp = needed;
396 return (error);
397 }
398
399 static int
sysctl_hw_iostats(SYSCTLFN_ARGS)400 sysctl_hw_iostats(SYSCTLFN_ARGS)
401 {
402 struct io_sysctl sdrive;
403 struct io_stats *stats;
404 char *where = oldp;
405 size_t tocopy, left;
406 int error;
407
408 if (newp != NULL)
409 return (EPERM);
410
411 /*
412 * The original hw.diskstats call was broken and did not require
413 * the userland to pass in its size of struct disk_sysctl. This
414 * was fixed after NetBSD 1.6 was released.
415 */
416 if (namelen == 0)
417 tocopy = offsetof(struct io_sysctl, busy);
418 else
419 tocopy = name[0];
420
421 if (where == NULL) {
422 *oldlenp = iostat_count * tocopy;
423 return (0);
424 }
425
426 error = 0;
427 left = *oldlenp;
428 memset(&sdrive, 0, sizeof(sdrive));
429 *oldlenp = 0;
430
431 rw_enter(&iostatlist_lock, RW_READER);
432 TAILQ_FOREACH(stats, &iostatlist, io_link) {
433 if (left < tocopy)
434 break;
435
436 strncpy(sdrive.name, stats->io_name, sizeof(sdrive.name));
437 sdrive.attachtime_sec = stats->io_attachtime.tv_sec;
438 sdrive.attachtime_usec = stats->io_attachtime.tv_usec;
439 sdrive.timestamp_sec = stats->io_busystamp.tv_sec;
440 sdrive.timestamp_usec = stats->io_busystamp.tv_usec;
441
442 sdrive.time_sec = stats->io_busytime.tv_sec;
443 sdrive.time_usec = stats->io_busytime.tv_usec;
444
445 sdrive.seek = stats->io_seek;
446
447 sdrive.rxfer = stats->io_rxfer;
448 sdrive.wxfer = stats->io_wxfer;
449 sdrive.xfer = stats->io_rxfer + stats->io_wxfer;
450
451 sdrive.rbytes = stats->io_rbytes;
452 sdrive.wbytes = stats->io_wbytes;
453 sdrive.bytes = stats->io_rbytes + stats->io_wbytes;
454
455 sdrive.wait_sec = stats->io_waittime.tv_sec;
456 sdrive.wait_usec = stats->io_waittime.tv_usec;
457
458 sdrive.time_sec = stats->io_busytime.tv_sec;
459 sdrive.time_usec = stats->io_busytime.tv_usec;
460
461 sdrive.waitsum_sec = stats->io_waitsum.tv_sec;
462 sdrive.waitsum_usec = stats->io_waitsum.tv_usec;
463
464 sdrive.busysum_sec = stats->io_busysum.tv_sec;
465 sdrive.busysum_usec = stats->io_busysum.tv_usec;
466
467 sdrive.busy = stats->io_busy;
468
469 error = copyout(&sdrive, where, uimin(tocopy, sizeof(sdrive)));
470 if (error)
471 break;
472 where += tocopy;
473 *oldlenp += tocopy;
474 left -= tocopy;
475 }
476 rw_exit(&iostatlist_lock);
477 return (error);
478 }
479
480 static void
sysctl_io_stats_setup(struct sysctllog ** clog)481 sysctl_io_stats_setup(struct sysctllog **clog)
482 {
483
484 sysctl_createv(clog, 0, NULL, NULL,
485 CTLFLAG_PERMANENT,
486 CTLTYPE_STRING, "disknames",
487 SYSCTL_DESCR("List of disk drives present"),
488 sysctl_hw_disknames, 0, NULL, 0,
489 CTL_HW, HW_DISKNAMES, CTL_EOL);
490 sysctl_createv(clog, 0, NULL, NULL,
491 CTLFLAG_PERMANENT,
492 CTLTYPE_STRING, "iostatnames",
493 SYSCTL_DESCR("I/O stats are being collected for these"
494 " devices"),
495 sysctl_hw_iostatnames, 0, NULL, 0,
496 CTL_HW, HW_IOSTATNAMES, CTL_EOL);
497 sysctl_createv(clog, 0, NULL, NULL,
498 CTLFLAG_PERMANENT,
499 CTLTYPE_STRUCT, "iostats",
500 SYSCTL_DESCR("Statistics on device I/O operations"),
501 sysctl_hw_iostats, 0, NULL, 0,
502 CTL_HW, HW_IOSTATS, CTL_EOL);
503 }
504