2 * Copyright (c) 1997, 1998, 1999 Kenneth D. Merry.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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9 * notice, this list of conditions and the following disclaimer.
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14 * derived from this software without specific prior written permission.
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28 * $FreeBSD: src/sys/kern/subr_devstat.c,v 1.17.2.2 2000/08/03 00:09:32 ps Exp $
29 * $DragonFly: src/sys/kern/subr_devstat.c,v 1.4 2006/12/23 00:35:04 swildner Exp $
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/systm.h>
36 #include <sys/sysctl.h>
38 #include <sys/devicestat.h>
40 static int devstat_num_devs;
41 static long devstat_generation;
42 static int devstat_version = DEVSTAT_VERSION;
43 static int devstat_current_devnumber;
45 static STAILQ_HEAD(devstatlist, devstat) device_statq;
48 * Take a malloced and zeroed devstat structure given to us, fill it in
49 * and add it to the queue of devices.
52 devstat_add_entry(struct devstat *ds, const char *dev_name,
53 int unit_number, u_int32_t block_size,
54 devstat_support_flags flags,
55 devstat_type_flags device_type,
56 devstat_priority priority)
58 struct devstatlist *devstat_head;
59 struct devstat *ds_tmp;
64 if (devstat_num_devs == 0)
65 STAILQ_INIT(&device_statq);
70 devstat_head = &device_statq;
73 * Priority sort. Each driver passes in its priority when it adds
74 * its devstat entry. Drivers are sorted first by priority, and
75 * then by probe order.
77 * For the first device, we just insert it, since the priority
78 * doesn't really matter yet. Subsequent devices are inserted into
79 * the list using the order outlined above.
81 if (devstat_num_devs == 1)
82 STAILQ_INSERT_TAIL(devstat_head, ds, dev_links);
84 for (ds_tmp = STAILQ_FIRST(devstat_head); ds_tmp != NULL;
85 ds_tmp = STAILQ_NEXT(ds_tmp, dev_links)) {
86 struct devstat *ds_next;
88 ds_next = STAILQ_NEXT(ds_tmp, dev_links);
91 * If we find a break between higher and lower
92 * priority items, and if this item fits in the
93 * break, insert it. This also applies if the
94 * "lower priority item" is the end of the list.
96 if ((priority <= ds_tmp->priority)
98 || (priority > ds_next->priority))) {
99 STAILQ_INSERT_AFTER(devstat_head, ds_tmp, ds,
102 } else if (priority > ds_tmp->priority) {
104 * If this is the case, we should be able
105 * to insert ourselves at the head of the
106 * list. If we can't, something is wrong.
108 if (ds_tmp == STAILQ_FIRST(devstat_head)) {
109 STAILQ_INSERT_HEAD(devstat_head,
113 STAILQ_INSERT_TAIL(devstat_head,
115 kprintf("devstat_add_entry: HELP! "
116 "sorting problem detected "
117 "for %s%d\n", dev_name,
125 ds->device_number = devstat_current_devnumber++;
126 ds->unit_number = unit_number;
127 strncpy(ds->device_name, dev_name, DEVSTAT_NAME_LEN);
128 ds->device_name[DEVSTAT_NAME_LEN - 1] = '\0';
129 ds->block_size = block_size;
131 ds->device_type = device_type;
132 ds->priority = priority;
133 getmicrotime(&ds->dev_creation_time);
137 * Remove a devstat structure from the list of devices.
140 devstat_remove_entry(struct devstat *ds)
142 struct devstatlist *devstat_head;
147 devstat_generation++;
150 devstat_head = &device_statq;
152 /* Remove this entry from the devstat queue */
153 STAILQ_REMOVE(devstat_head, ds, devstat, dev_links);
157 * Record a transaction start.
160 devstat_start_transaction(struct devstat *ds)
167 * We only want to set the start time when we are going from idle
168 * to busy. The start time is really the start of the latest busy
171 if (ds->busy_count == 0)
172 getmicrouptime(&ds->start_time);
177 * Record the ending of a transaction, and incrment the various counters.
180 devstat_end_transaction(struct devstat *ds, u_int32_t bytes,
181 devstat_tag_type tag_type, devstat_trans_flags flags)
183 struct timeval busy_time;
189 getmicrouptime(&ds->last_comp_time);
193 * There might be some transactions (DEVSTAT_NO_DATA) that don't
196 if (flags == DEVSTAT_READ) {
197 ds->bytes_read += bytes;
199 } else if (flags == DEVSTAT_WRITE) {
200 ds->bytes_written += bytes;
202 } else if (flags == DEVSTAT_FREE) {
203 ds->bytes_freed += bytes;
209 * Keep a count of the various tag types sent.
211 if ((ds->flags & DEVSTAT_NO_ORDERED_TAGS) == 0 &&
212 tag_type != DEVSTAT_TAG_NONE)
213 ds->tag_types[tag_type]++;
216 * We only update the busy time when we go idle. Otherwise, this
217 * calculation would require many more clock cycles.
219 if (ds->busy_count == 0) {
220 /* Calculate how long we were busy */
221 busy_time = ds->last_comp_time;
222 timevalsub(&busy_time, &ds->start_time);
224 /* Add our busy time to the total busy time. */
225 timevaladd(&ds->busy_time, &busy_time);
226 } else if (ds->busy_count < 0)
227 kprintf("devstat_end_transaction: HELP!! busy_count "
228 "for %s%d is < 0 (%d)!\n", ds->device_name,
229 ds->unit_number, ds->busy_count);
233 devstat_end_transaction_buf(struct devstat *ds, struct buf *bp)
235 devstat_trans_flags flg;
238 case BUF_CMD_FREEBLKS:
248 devstat_end_transaction(ds, bp->b_bcount - bp->b_resid,
249 (bp->b_flags & B_ORDERED) ?
250 DEVSTAT_TAG_ORDERED : DEVSTAT_TAG_SIMPLE, flg);
254 * This is the sysctl handler for the devstat package. The data pushed out
255 * on the kern.devstat.all sysctl variable consists of the current devstat
256 * generation number, and then an array of devstat structures, one for each
257 * device in the system.
259 * I'm really not too fond of this method of doing things, but there really
260 * aren't that many alternatives. We must have some method of making sure
261 * that the generation number the user gets corresponds with the data the
262 * user gets. If the user makes a separate sysctl call to get the
263 * generation, and then a sysctl call to get the device statistics, the
264 * device list could have changed in that brief period of time. By
265 * supplying the generation number along with the statistics output, we can
266 * guarantee that the generation number and the statistics match up.
269 sysctl_devstat(SYSCTL_HANDLER_ARGS)
273 struct devstatlist *devstat_head;
275 if (devstat_num_devs == 0)
279 devstat_head = &device_statq;
282 * First push out the generation number.
284 error = SYSCTL_OUT(req, &devstat_generation, sizeof(long));
287 * Now push out all the devices.
289 for (i = 0, nds = STAILQ_FIRST(devstat_head);
290 (nds != NULL) && (i < devstat_num_devs) && (error == 0);
291 nds = STAILQ_NEXT(nds, dev_links), i++)
292 error = SYSCTL_OUT(req, nds, sizeof(struct devstat));
298 * Sysctl entries for devstat. The first one is a node that all the rest
301 SYSCTL_NODE(_kern, OID_AUTO, devstat, CTLFLAG_RD, 0, "Device Statistics");
303 SYSCTL_PROC(_kern_devstat, OID_AUTO, all, CTLFLAG_RD|CTLTYPE_OPAQUE,
304 0, 0, sysctl_devstat, "S,devstat", "All devices in the devstat list");
306 * Export the number of devices in the system so that userland utilities
307 * can determine how much memory to allocate to hold all the devices.
309 SYSCTL_INT(_kern_devstat, OID_AUTO, numdevs, CTLFLAG_RD,
310 &devstat_num_devs, 0, "Number of devices in the devstat list");
311 SYSCTL_LONG(_kern_devstat, OID_AUTO, generation, CTLFLAG_RD,
312 &devstat_generation, 0, "Devstat list generation");
313 SYSCTL_INT(_kern_devstat, OID_AUTO, version, CTLFLAG_RD,
314 &devstat_version, 0, "Devstat list version number");