diff options
Diffstat (limited to 'sys/kern/subr_devstat.c')
| -rw-r--r-- | sys/kern/subr_devstat.c | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/sys/kern/subr_devstat.c b/sys/kern/subr_devstat.c new file mode 100644 index 0000000..dabdf9d --- /dev/null +++ b/sys/kern/subr_devstat.c @@ -0,0 +1,307 @@ +/* + * 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. + * + * $FreeBSD$ + */ + +#include <sys/param.h> +#include <sys/kernel.h> +#include <sys/systm.h> +#include <sys/bio.h> +#include <sys/sysctl.h> + +#include <sys/devicestat.h> + +static int devstat_num_devs; +static long devstat_generation; +static int devstat_version = DEVSTAT_VERSION; +static int devstat_current_devnumber; + +static struct devstatlist 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 { + STAILQ_FOREACH(ds_tmp, devstat_head, 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); + printf("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 (ds->busy_count == 0) + getmicrouptime(&ds->start_time); + ds->busy_count++; +} + +/* + * 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; + + /* sanity check */ + if (ds == NULL) + return; + + getmicrouptime(&ds->last_comp_time); + ds->busy_count--; + + /* + * 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 (ds->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 (ds->busy_count < 0) + printf("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_bio(struct devstat *ds, struct bio *bp) +{ + devstat_trans_flags flg; + + if (bp->bio_cmd == BIO_DELETE) + flg = DEVSTAT_FREE; + else if (bp->bio_cmd == BIO_READ) + flg = DEVSTAT_READ; + else + flg = DEVSTAT_WRITE; + + devstat_end_transaction(ds, bp->bio_bcount - bp->bio_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"); |
