xref: /netbsd-src/sys/kern/subr_iostat.c (revision 53b02e147d4ed531c0d2a5ca9b3e8026ba3e99b5)
1 /*	$NetBSD: subr_iostat.c,v 1.25 2019/05/22 08:47:02 hannken 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 1.25 2019/05/22 08:47:02 hannken 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
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 *
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 *
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
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
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
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
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
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
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
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
321 iostat_seek(struct io_stats *stats)
322 {
323 
324 	stats->io_seek++;
325 }
326 
327 static int
328 sysctl_hw_disknames(SYSCTLFN_ARGS)
329 {
330 
331 	return iostati_getnames(1, oldp, oldlenp, newp, namelen);
332 }
333 
334 static int
335 sysctl_hw_iostatnames(SYSCTLFN_ARGS)
336 {
337 
338 	return iostati_getnames(0, oldp, oldlenp, newp, namelen);
339 }
340 
341 static int
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 				first = 0;
374 			} else {
375 				bf[0] = ' ';
376 				strncpy(bf + 1, stats->io_name,
377 				    sizeof(bf) - 1);
378 			}
379 			bf[IOSTATNAMELEN] = '\0';
380 			slen = strlen(bf);
381 			if (left < slen + 1)
382 				break;
383 			/* +1 to copy out the trailing NUL byte */
384 			error = copyout(bf, where, slen + 1);
385 			if (error)
386 				break;
387 			where += slen;
388 			needed += slen;
389 			left -= slen;
390 		}
391 	}
392 	rw_exit(&iostatlist_lock);
393 	*oldlenp = needed;
394 	return (error);
395 }
396 
397 static int
398 sysctl_hw_iostats(SYSCTLFN_ARGS)
399 {
400 	struct io_sysctl sdrive;
401 	struct io_stats *stats;
402 	char *where = oldp;
403 	size_t tocopy, left;
404 	int error;
405 
406 	if (newp != NULL)
407 		return (EPERM);
408 
409 	/*
410 	 * The original hw.diskstats call was broken and did not require
411 	 * the userland to pass in its size of struct disk_sysctl.  This
412 	 * was fixed after NetBSD 1.6 was released.
413 	 */
414 	if (namelen == 0)
415 		tocopy = offsetof(struct io_sysctl, busy);
416 	else
417 		tocopy = name[0];
418 
419 	if (where == NULL) {
420 		*oldlenp = iostat_count * tocopy;
421 		return (0);
422 	}
423 
424 	error = 0;
425 	left = *oldlenp;
426 	memset(&sdrive, 0, sizeof(sdrive));
427 	*oldlenp = 0;
428 
429 	rw_enter(&iostatlist_lock, RW_READER);
430 	TAILQ_FOREACH(stats, &iostatlist, io_link) {
431 		if (left < tocopy)
432 			break;
433 
434 		strncpy(sdrive.name, stats->io_name, sizeof(sdrive.name));
435 		sdrive.attachtime_sec = stats->io_attachtime.tv_sec;
436 		sdrive.attachtime_usec = stats->io_attachtime.tv_usec;
437 		sdrive.timestamp_sec = stats->io_busystamp.tv_sec;
438 		sdrive.timestamp_usec = stats->io_busystamp.tv_usec;
439 
440 		sdrive.time_sec = stats->io_busytime.tv_sec;
441 		sdrive.time_usec = stats->io_busytime.tv_usec;
442 
443 		sdrive.seek = stats->io_seek;
444 
445 		sdrive.rxfer = stats->io_rxfer;
446 		sdrive.wxfer = stats->io_wxfer;
447 		sdrive.xfer = stats->io_rxfer + stats->io_wxfer;
448 
449 		sdrive.rbytes = stats->io_rbytes;
450 		sdrive.wbytes = stats->io_wbytes;
451 		sdrive.bytes = stats->io_rbytes + stats->io_wbytes;
452 
453 		sdrive.wait_sec = stats->io_waittime.tv_sec;
454 		sdrive.wait_usec = stats->io_waittime.tv_usec;
455 
456 		sdrive.time_sec = stats->io_busytime.tv_sec;
457 		sdrive.time_usec = stats->io_busytime.tv_usec;
458 
459 		sdrive.waitsum_sec = stats->io_waitsum.tv_sec;
460 		sdrive.waitsum_usec = stats->io_waitsum.tv_usec;
461 
462 		sdrive.busysum_sec = stats->io_busysum.tv_sec;
463 		sdrive.busysum_usec = stats->io_busysum.tv_usec;
464 
465 		sdrive.busy = stats->io_busy;
466 
467 		error = copyout(&sdrive, where, uimin(tocopy, sizeof(sdrive)));
468 		if (error)
469 			break;
470 		where += tocopy;
471 		*oldlenp += tocopy;
472 		left -= tocopy;
473 	}
474 	rw_exit(&iostatlist_lock);
475 	return (error);
476 }
477 
478 static void
479 sysctl_io_stats_setup(struct sysctllog **clog)
480 {
481 
482 	sysctl_createv(clog, 0, NULL, NULL,
483 		       CTLFLAG_PERMANENT,
484 		       CTLTYPE_STRING, "disknames",
485 		       SYSCTL_DESCR("List of disk drives present"),
486 		       sysctl_hw_disknames, 0, NULL, 0,
487 		       CTL_HW, HW_DISKNAMES, CTL_EOL);
488 	sysctl_createv(clog, 0, NULL, NULL,
489 		       CTLFLAG_PERMANENT,
490 		       CTLTYPE_STRING, "iostatnames",
491 		       SYSCTL_DESCR("I/O stats are being collected for these"
492 				    " devices"),
493 		       sysctl_hw_iostatnames, 0, NULL, 0,
494 		       CTL_HW, HW_IOSTATNAMES, CTL_EOL);
495 	sysctl_createv(clog, 0, NULL, NULL,
496 		       CTLFLAG_PERMANENT,
497 		       CTLTYPE_STRUCT, "iostats",
498 		       SYSCTL_DESCR("Statistics on device I/O operations"),
499 		       sysctl_hw_iostats, 0, NULL, 0,
500 		       CTL_HW, HW_IOSTATS, CTL_EOL);
501 }
502