1 /* 2 * Copyright (c) 1997, 1998 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 * $Id: subr_devstat.c,v 1.3 1998/10/06 04:16:07 ken Exp $ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/kernel.h> 33 #include <sys/systm.h> 34 #include <sys/time.h> 35 #include <sys/types.h> 36 #include <sys/sysctl.h> 37 38 #include <sys/devicestat.h> 39 40 static int devstat_num_devs; 41 static long devstat_generation; 42 static int devstat_version = DEVSTAT_VERSION; 43 static int devstat_current_devnumber; 44 45 STAILQ_HEAD(devstatlist, devstat) device_statq; 46 47 /* 48 * Take a malloced and zeroed devstat structure given to us, fill it in 49 * and add it to the queue of devices. 50 */ 51 void 52 devstat_add_entry(struct devstat *ds, char *dev_name, 53 int unit_number, u_int32_t block_size, 54 devstat_support_flags flags, 55 devstat_type_flags device_type) 56 { 57 int s; 58 struct devstatlist *devstat_head; 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 STAILQ_INSERT_TAIL(devstat_head, ds, dev_links); 72 73 ds->device_number = devstat_current_devnumber++; 74 ds->unit_number = unit_number; 75 strncpy(ds->device_name, dev_name, DEVSTAT_NAME_LEN); 76 ds->block_size = block_size; 77 ds->flags = flags; 78 ds->device_type = device_type; 79 80 s = splclock(); 81 getmicrotime(&ds->dev_creation_time); 82 splx(s); 83 } 84 85 /* 86 * Remove a devstat structure from the list of devices. 87 */ 88 void 89 devstat_remove_entry(struct devstat *ds) 90 { 91 struct devstatlist *devstat_head; 92 93 if (ds == NULL) 94 return; 95 96 devstat_generation++; 97 devstat_num_devs--; 98 99 devstat_head = &device_statq; 100 101 /* Remove this entry from the devstat queue */ 102 STAILQ_REMOVE(devstat_head, ds, devstat, dev_links); 103 } 104 105 /* 106 * Record a transaction start. 107 */ 108 void 109 devstat_start_transaction(struct devstat *ds) 110 { 111 int s; 112 113 /* sanity check */ 114 if (ds == NULL) 115 return; 116 117 /* 118 * We only want to set the start time when we are going from idle 119 * to busy. The start time is really the start of the latest busy 120 * period. 121 */ 122 if (ds->busy_count == 0) { 123 s = splclock(); 124 getmicrouptime(&ds->start_time); 125 splx(s); 126 } 127 ds->busy_count++; 128 } 129 130 /* 131 * Record the ending of a transaction, and incrment the various counters. 132 */ 133 void 134 devstat_end_transaction(struct devstat *ds, u_int32_t bytes, 135 devstat_tag_type tag_type, devstat_trans_flags flags) 136 { 137 int s; 138 struct timeval busy_time; 139 140 /* sanity check */ 141 if (ds == NULL) 142 return; 143 144 s = splclock(); 145 getmicrouptime(&ds->last_comp_time); 146 splx(s); 147 148 ds->busy_count--; 149 150 /* 151 * There might be some transactions (DEVSTAT_NO_DATA) that don't 152 * transfer any data. 153 */ 154 if (flags == DEVSTAT_READ) { 155 ds->bytes_read += bytes; 156 ds->num_reads++; 157 } else if (flags == DEVSTAT_WRITE) { 158 ds->bytes_written += bytes; 159 ds->num_writes++; 160 } else 161 ds->num_other++; 162 163 /* 164 * Keep a count of the various tag types sent. 165 */ 166 if (tag_type != DEVSTAT_TAG_NONE) 167 ds->tag_types[tag_type]++; 168 169 /* 170 * We only update the busy time when we go idle. Otherwise, this 171 * calculation would require many more clock cycles. 172 */ 173 if (ds->busy_count == 0) { 174 /* Calculate how long we were busy */ 175 busy_time = ds->last_comp_time; 176 timevalsub(&busy_time, &ds->start_time); 177 178 /* Add our busy time to the total busy time. */ 179 timevaladd(&ds->busy_time, &busy_time); 180 } 181 /* 182 * XXX KDM this is temporarily disabled to avoid causing 183 * unsophisticated users to panic. There are unfixed bugs in the 184 * wd driver that will set off this error message. 185 */ 186 #if 0 187 else if (ds->busy_count < 0) 188 printf("devstat_end_transaction: HELP!! busy_count " 189 "for %s%d is < 0 (%d)!\n", ds->device_name, 190 ds->unit_number, ds->busy_count); 191 #endif 192 } 193 194 /* 195 * This is the sysctl handler for the devstat package. The data pushed out 196 * on the kern.devstat.all sysctl variable consists of the current devstat 197 * generation number, and then an array of devstat structures, one for each 198 * device in the system. 199 * 200 * I'm really not too fond of this method of doing things, but there really 201 * aren't that many alternatives. We must have some method of making sure 202 * that the generation number the user gets corresponds with the data the 203 * user gets. If the user makes a separate sysctl call to get the 204 * generation, and then a sysctl call to get the device statistics, the 205 * device list could have changed in that brief period of time. By 206 * supplying the generation number along with the statistics output, we can 207 * guarantee that the generation number and the statistics match up. 208 */ 209 static int 210 sysctl_devstat SYSCTL_HANDLER_ARGS 211 { 212 int error, i; 213 struct devstat *nds; 214 struct devstatlist *devstat_head; 215 216 if (devstat_num_devs == 0) 217 return(EINVAL); 218 219 error = 0; 220 devstat_head = &device_statq; 221 222 /* 223 * First push out the generation number. 224 */ 225 error = SYSCTL_OUT(req, &devstat_generation, sizeof(long)); 226 227 /* 228 * Now push out all the devices. 229 */ 230 for (i = 0, nds = devstat_head->stqh_first; 231 (nds != NULL) && (i < devstat_num_devs) && (error == 0); 232 nds = nds->dev_links.stqe_next, i++) 233 error = SYSCTL_OUT(req, nds, sizeof(struct devstat)); 234 235 return(error); 236 } 237 238 /* 239 * Sysctl entries for devstat. The first one is a node that all the rest 240 * hang off of. 241 */ 242 SYSCTL_NODE(_kern, OID_AUTO, devstat, CTLFLAG_RD, 0, "Device Statistics"); 243 244 SYSCTL_PROC(_kern_devstat, OID_AUTO, all, CTLFLAG_RD|CTLTYPE_OPAQUE, 245 0, 0, sysctl_devstat, "S,devstat", "All Devices"); 246 /* 247 * Export the number of devices in the system so that userland utilities 248 * can determine how much memory to allocate to hold all the devices. 249 */ 250 SYSCTL_INT(_kern_devstat, OID_AUTO, numdevs, CTLFLAG_RD, &devstat_num_devs, 251 0, "Number of devices in the devstat list"); 252 SYSCTL_LONG(_kern_devstat, OID_AUTO, generation, CTLFLAG_RD, 253 &devstat_generation, 0, "Devstat list generation"); 254 SYSCTL_INT(_kern_devstat, OID_AUTO, version, CTLFLAG_RD, &devstat_version, 255 0, "Devstat list version number"); 256