From 78f0dc839b3d746460e6fd2f0ffbb260bf45504c Mon Sep 17 00:00:00 2001 From: gibbs Date: Tue, 15 Sep 1998 08:16:17 +0000 Subject: New Kernel device statistics code. Submitted by: "Kenneth D. Merry" --- sys/kern/subr_devstat.c | 245 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 245 insertions(+) create mode 100644 sys/kern/subr_devstat.c (limited to 'sys/kern') diff --git a/sys/kern/subr_devstat.c b/sys/kern/subr_devstat.c new file mode 100644 index 0000000..fe1f832 --- /dev/null +++ b/sys/kern/subr_devstat.c @@ -0,0 +1,245 @@ +/* + * Copyright (c) 1997, 1998 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. + * + * $Id$ + */ + +#include +#include +#include +#include +#include +#include + +#include + +static int devstat_num_devs; +static int devstat_generation; +static int devstat_version = DEVSTAT_VERSION; +static int devstat_current_devnumber; + +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, char *dev_name, + int unit_number, u_int32_t block_size, + devstat_support_flags flags, + devstat_type_flags device_type) +{ + int s; + struct devstatlist *devstat_head; + + if (ds == NULL) + return; + + if (devstat_num_devs == 0) + STAILQ_INIT(&device_statq); + + devstat_generation++; + devstat_num_devs++; + + devstat_head = &device_statq; + + STAILQ_INSERT_TAIL(devstat_head, ds, dev_links); + + ds->device_number = devstat_current_devnumber++; + ds->unit_number = unit_number; + strncpy(ds->device_name, dev_name, DEVSTAT_NAME_LEN); + ds->block_size = block_size; + ds->flags = flags; + ds->device_type = device_type; + + s = splclock(); + getmicrotime(&ds->dev_creation_time); + splx(s); +} + +/* + * 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) +{ + int s; + + /* 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) { + s = splclock(); + getmicrouptime(&ds->start_time); + splx(s); + } + 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) +{ + int s; + struct timeval busy_time; + + /* sanity check */ + if (ds == NULL) + return; + + s = splclock(); + getmicrouptime(&ds->last_comp_time); + splx(s); + + 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 + ds->num_other++; + + /* + * Keep a count of the various tag types sent. + */ + if (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 is < 0!\n"); +} + +/* + * 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(int)); + + /* + * Now push out all the devices. + */ + for (i = 0, nds = devstat_head->stqh_first; + (nds != NULL) && (i < devstat_num_devs) && (error == 0); + nds = nds->dev_links.stqe_next, 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"); +/* + * 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_INT(_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"); -- cgit v1.1