/* * Copyright (c) 1997, 1998, 1999 Kenneth D. Merry. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD: src/sys/kern/subr_devstat.c,v 1.17.2.2 2000/08/03 00:09:32 ps Exp $ * $DragonFly: src/sys/kern/subr_devstat.c,v 1.4 2006/12/23 00:35:04 swildner Exp $ */ #include #include #include #include #include #include static int devstat_num_devs; static long devstat_generation; static int devstat_version = DEVSTAT_VERSION; static int devstat_current_devnumber; static STAILQ_HEAD(devstatlist, devstat) device_statq; /* * Take a malloced and zeroed devstat structure given to us, fill it in * and add it to the queue of devices. */ void devstat_add_entry(struct devstat *ds, const char *dev_name, int unit_number, u_int32_t block_size, devstat_support_flags flags, devstat_type_flags device_type, devstat_priority priority) { struct devstatlist *devstat_head; struct devstat *ds_tmp; if (ds == NULL) return; if (devstat_num_devs == 0) STAILQ_INIT(&device_statq); devstat_generation++; devstat_num_devs++; devstat_head = &device_statq; /* * Priority sort. Each driver passes in its priority when it adds * its devstat entry. Drivers are sorted first by priority, and * then by probe order. * * For the first device, we just insert it, since the priority * doesn't really matter yet. Subsequent devices are inserted into * the list using the order outlined above. */ if (devstat_num_devs == 1) STAILQ_INSERT_TAIL(devstat_head, ds, dev_links); else { for (ds_tmp = STAILQ_FIRST(devstat_head); ds_tmp != NULL; ds_tmp = STAILQ_NEXT(ds_tmp, dev_links)) { struct devstat *ds_next; ds_next = STAILQ_NEXT(ds_tmp, dev_links); /* * If we find a break between higher and lower * priority items, and if this item fits in the * break, insert it. This also applies if the * "lower priority item" is the end of the list. */ if ((priority <= ds_tmp->priority) && ((ds_next == NULL) || (priority > ds_next->priority))) { STAILQ_INSERT_AFTER(devstat_head, ds_tmp, ds, dev_links); break; } else if (priority > ds_tmp->priority) { /* * If this is the case, we should be able * to insert ourselves at the head of the * list. If we can't, something is wrong. */ if (ds_tmp == STAILQ_FIRST(devstat_head)) { STAILQ_INSERT_HEAD(devstat_head, ds, dev_links); break; } else { STAILQ_INSERT_TAIL(devstat_head, ds, dev_links); kprintf("devstat_add_entry: HELP! " "sorting problem detected " "for %s%d\n", dev_name, unit_number); break; } } } } ds->device_number = devstat_current_devnumber++; ds->unit_number = unit_number; strncpy(ds->device_name, dev_name, DEVSTAT_NAME_LEN); ds->device_name[DEVSTAT_NAME_LEN - 1] = '\0'; ds->block_size = block_size; ds->flags = flags; ds->device_type = device_type; ds->priority = priority; getmicrotime(&ds->dev_creation_time); } /* * Remove a devstat structure from the list of devices. */ void devstat_remove_entry(struct devstat *ds) { struct devstatlist *devstat_head; if (ds == NULL) return; devstat_generation++; devstat_num_devs--; devstat_head = &device_statq; /* Remove this entry from the devstat queue */ STAILQ_REMOVE(devstat_head, ds, devstat, dev_links); } /* * Record a transaction start. */ void devstat_start_transaction(struct devstat *ds) { /* sanity check */ if (ds == NULL) return; /* * We only want to set the start time when we are going from idle * to busy. The start time is really the start of the latest busy * period. */ if (atomic_fetchadd_int(&ds->busy_count, 1) == 0) getmicrouptime(&ds->start_time); } /* * Record the ending of a transaction, and incrment the various counters. */ void devstat_end_transaction(struct devstat *ds, u_int32_t bytes, devstat_tag_type tag_type, devstat_trans_flags flags) { struct timeval busy_time; int busy_count; /* sanity check */ if (ds == NULL) return; getmicrouptime(&ds->last_comp_time); busy_count = atomic_fetchadd_int(&ds->busy_count, -1) - 1; /* * There might be some transactions (DEVSTAT_NO_DATA) that don't * transfer any data. */ if (flags == DEVSTAT_READ) { ds->bytes_read += bytes; ds->num_reads++; } else if (flags == DEVSTAT_WRITE) { ds->bytes_written += bytes; ds->num_writes++; } else if (flags == DEVSTAT_FREE) { ds->bytes_freed += bytes; ds->num_frees++; } else ds->num_other++; /* * Keep a count of the various tag types sent. */ if ((ds->flags & DEVSTAT_NO_ORDERED_TAGS) == 0 && tag_type != DEVSTAT_TAG_NONE) ds->tag_types[tag_type]++; /* * We only update the busy time when we go idle. Otherwise, this * calculation would require many more clock cycles. */ if (busy_count == 0) { /* Calculate how long we were busy */ busy_time = ds->last_comp_time; timevalsub(&busy_time, &ds->start_time); /* Add our busy time to the total busy time. */ timevaladd(&ds->busy_time, &busy_time); } else if (busy_count < 0) { kprintf("devstat_end_transaction: HELP!! busy_count " "for %s%d is < 0 (%d)!\n", ds->device_name, ds->unit_number, ds->busy_count); } } void devstat_end_transaction_buf(struct devstat *ds, struct buf *bp) { devstat_trans_flags flg; switch(bp->b_cmd) { case BUF_CMD_FREEBLKS: flg = DEVSTAT_FREE; break; case BUF_CMD_READ: flg = DEVSTAT_READ; break; default: flg = DEVSTAT_WRITE; break; } devstat_end_transaction(ds, bp->b_bcount - bp->b_resid, DEVSTAT_TAG_SIMPLE, flg); } /* * This is the sysctl handler for the devstat package. The data pushed out * on the kern.devstat.all sysctl variable consists of the current devstat * generation number, and then an array of devstat structures, one for each * device in the system. * * I'm really not too fond of this method of doing things, but there really * aren't that many alternatives. We must have some method of making sure * that the generation number the user gets corresponds with the data the * user gets. If the user makes a separate sysctl call to get the * generation, and then a sysctl call to get the device statistics, the * device list could have changed in that brief period of time. By * supplying the generation number along with the statistics output, we can * guarantee that the generation number and the statistics match up. */ static int sysctl_devstat(SYSCTL_HANDLER_ARGS) { int error, i; struct devstat *nds; struct devstatlist *devstat_head; if (devstat_num_devs == 0) return(EINVAL); error = 0; devstat_head = &device_statq; /* * First push out the generation number. */ error = SYSCTL_OUT(req, &devstat_generation, sizeof(long)); /* * Now push out all the devices. */ for (i = 0, nds = STAILQ_FIRST(devstat_head); (nds != NULL) && (i < devstat_num_devs) && (error == 0); nds = STAILQ_NEXT(nds, dev_links), i++) error = SYSCTL_OUT(req, nds, sizeof(struct devstat)); return(error); } /* * Sysctl entries for devstat. The first one is a node that all the rest * hang off of. */ SYSCTL_NODE(_kern, OID_AUTO, devstat, CTLFLAG_RD, 0, "Device Statistics"); SYSCTL_PROC(_kern_devstat, OID_AUTO, all, CTLFLAG_RD|CTLTYPE_OPAQUE, 0, 0, sysctl_devstat, "S,devstat", "All devices in the devstat list"); /* * Export the number of devices in the system so that userland utilities * can determine how much memory to allocate to hold all the devices. */ SYSCTL_INT(_kern_devstat, OID_AUTO, numdevs, CTLFLAG_RD, &devstat_num_devs, 0, "Number of devices in the devstat list"); SYSCTL_LONG(_kern_devstat, OID_AUTO, generation, CTLFLAG_RD, &devstat_generation, 0, "Devstat list generation"); SYSCTL_INT(_kern_devstat, OID_AUTO, version, CTLFLAG_RD, &devstat_version, 0, "Devstat list version number");