NetBSD/sys/kern/subr_iostat.c

412 lines
11 KiB
C

/* $NetBSD: subr_iostat.c,v 1.19 2009/11/30 11:28:35 pooka Exp $ */
/* NetBSD: subr_disk.c,v 1.69 2005/05/29 22:24:15 christos Exp */
/*-
* Copyright (c) 1996, 1997, 1999, 2000, 2009 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Copyright (c) 1982, 1986, 1988, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_iostat.c,v 1.19 2009/11/30 11:28:35 pooka Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/kmem.h>
#include <sys/iostat.h>
#include <sys/sysctl.h>
#include <sys/rwlock.h>
/*
* Function prototypes for sysctl nodes
*/
static int sysctl_hw_disknames(SYSCTLFN_PROTO);
static int sysctl_hw_iostatnames(SYSCTLFN_PROTO);
static int sysctl_hw_iostats(SYSCTLFN_PROTO);
static int
iostati_getnames(int disk_only, char *oldp, size_t *oldlenp, const void *newp,
u_int namelen);
/*
* A global list of all drives attached to the system. May grow or
* shrink over time.
*/
struct iostatlist_head iostatlist = TAILQ_HEAD_INITIALIZER(iostatlist);
int iostat_count; /* number of drives in global drivelist */
krwlock_t iostatlist_lock;
static void sysctl_io_stats_setup(struct sysctllog **);
/*
* Initialise the iostat subsystem.
*/
void
iostat_init(void)
{
rw_init(&iostatlist_lock);
sysctl_io_stats_setup(NULL);
}
/*
* Searches the iostatlist for the iostat corresponding to the
* name provided.
*/
struct io_stats *
iostat_find(const char *name)
{
struct io_stats *iostatp;
KASSERT(name != NULL);
rw_enter(&iostatlist_lock, RW_READER);
TAILQ_FOREACH(iostatp, &iostatlist, io_link) {
if (strcmp(iostatp->io_name, name) == 0) {
break;
}
}
rw_exit(&iostatlist_lock);
return iostatp;
}
/*
* Allocate and initialise memory for the i/o statistics.
*/
struct io_stats *
iostat_alloc(int32_t type, void *parent, const char *name)
{
struct io_stats *stats;
stats = kmem_zalloc(sizeof(*stats), KM_SLEEP);
if (stats == NULL)
panic("iostat_alloc: cannot allocate memory for stats buffer");
stats->io_type = type;
stats->io_parent = parent;
(void)strlcpy(stats->io_name, name, sizeof(stats->io_name));
/*
* Set the attached timestamp.
*/
getmicrouptime(&stats->io_attachtime);
/*
* Link into the drivelist.
*/
rw_enter(&iostatlist_lock, RW_WRITER);
TAILQ_INSERT_TAIL(&iostatlist, stats, io_link);
iostat_count++;
rw_exit(&iostatlist_lock);
return stats;
}
/*
* Remove i/o from stats collection.
*/
void
iostat_free(struct io_stats *stats)
{
/*
* Remove from the iostat list.
*/
if (iostat_count == 0)
panic("iostat_free: iostat_count == 0");
rw_enter(&iostatlist_lock, RW_WRITER);
TAILQ_REMOVE(&iostatlist, stats, io_link);
iostat_count--;
rw_exit(&iostatlist_lock);
kmem_free(stats, sizeof(*stats));
}
/*
* Increment a iostat busy counter. If the counter is going from
* 0 to 1, set the timestamp.
*/
void
iostat_busy(struct io_stats *stats)
{
if (stats->io_busy++ == 0)
getmicrouptime(&stats->io_timestamp);
}
/*
* Decrement a iostat busy counter, increment the byte count, total busy
* time, and reset the timestamp.
*/
void
iostat_unbusy(struct io_stats *stats, long bcount, int read)
{
struct timeval dv_time, diff_time;
if (stats->io_busy-- == 0) {
printf("%s: busy < 0\n", stats->io_name);
panic("iostat_unbusy");
}
getmicrouptime(&dv_time);
timersub(&dv_time, &stats->io_timestamp, &diff_time);
timeradd(&stats->io_time, &diff_time, &stats->io_time);
stats->io_timestamp = dv_time;
if (bcount > 0) {
if (read) {
stats->io_rbytes += bcount;
stats->io_rxfer++;
} else {
stats->io_wbytes += bcount;
stats->io_wxfer++;
}
}
}
/*
* Return non-zero if a device has an I/O request in flight.
*/
bool
iostat_isbusy(struct io_stats *stats)
{
return stats->io_busy != 0;
}
/*
* Increment the seek counter. This does look almost redundant but it
* abstracts the stats gathering.
*/
void
iostat_seek(struct io_stats *stats)
{
stats->io_seek++;
}
static int
sysctl_hw_disknames(SYSCTLFN_ARGS)
{
return iostati_getnames(1, oldp, oldlenp, newp, namelen);
}
static int
sysctl_hw_iostatnames(SYSCTLFN_ARGS)
{
return iostati_getnames(0, oldp, oldlenp, newp, namelen);
}
static int
iostati_getnames(int disk_only, char *oldp, size_t *oldlenp, const void *newp,
u_int namelen)
{
char bf[IOSTATNAMELEN + 1];
char *where = oldp;
struct io_stats *stats;
size_t needed, left, slen;
int error, first;
if (newp != NULL)
return (EPERM);
if (namelen != 0)
return (EINVAL);
first = 1;
error = 0;
needed = 0;
left = *oldlenp;
rw_enter(&iostatlist_lock, RW_READER);
for (stats = TAILQ_FIRST(&iostatlist); stats != NULL;
stats = TAILQ_NEXT(stats, io_link)) {
if ((disk_only == 1) && (stats->io_type != IOSTAT_DISK))
continue;
if (where == NULL)
needed += strlen(stats->io_name) + 1;
else {
memset(bf, 0, sizeof(bf));
if (first) {
strncpy(bf, stats->io_name, sizeof(bf));
first = 0;
} else {
bf[0] = ' ';
strncpy(bf + 1, stats->io_name,
sizeof(bf) - 1);
}
bf[IOSTATNAMELEN] = '\0';
slen = strlen(bf);
if (left < slen + 1)
break;
/* +1 to copy out the trailing NUL byte */
error = copyout(bf, where, slen + 1);
if (error)
break;
where += slen;
needed += slen;
left -= slen;
}
}
rw_exit(&iostatlist_lock);
*oldlenp = needed;
return (error);
}
static int
sysctl_hw_iostats(SYSCTLFN_ARGS)
{
struct io_sysctl sdrive;
struct io_stats *stats;
char *where = oldp;
size_t tocopy, left;
int error;
if (newp != NULL)
return (EPERM);
/*
* The original hw.diskstats call was broken and did not require
* the userland to pass in it's size of struct disk_sysctl. This
* was fixed after NetBSD 1.6 was released.
*/
if (namelen == 0)
tocopy = offsetof(struct io_sysctl, busy);
else
tocopy = name[0];
if (where == NULL) {
*oldlenp = iostat_count * tocopy;
return (0);
}
error = 0;
left = *oldlenp;
memset(&sdrive, 0, sizeof(sdrive));
*oldlenp = 0;
rw_enter(&iostatlist_lock, RW_READER);
TAILQ_FOREACH(stats, &iostatlist, io_link) {
if (left < tocopy)
break;
strncpy(sdrive.name, stats->io_name, sizeof(sdrive.name));
sdrive.xfer = stats->io_rxfer + stats->io_wxfer;
sdrive.rxfer = stats->io_rxfer;
sdrive.wxfer = stats->io_wxfer;
sdrive.seek = stats->io_seek;
sdrive.bytes = stats->io_rbytes + stats->io_wbytes;
sdrive.rbytes = stats->io_rbytes;
sdrive.wbytes = stats->io_wbytes;
sdrive.attachtime_sec = stats->io_attachtime.tv_sec;
sdrive.attachtime_usec = stats->io_attachtime.tv_usec;
sdrive.timestamp_sec = stats->io_timestamp.tv_sec;
sdrive.timestamp_usec = stats->io_timestamp.tv_usec;
sdrive.time_sec = stats->io_time.tv_sec;
sdrive.time_usec = stats->io_time.tv_usec;
sdrive.busy = stats->io_busy;
error = copyout(&sdrive, where, min(tocopy, sizeof(sdrive)));
if (error)
break;
where += tocopy;
*oldlenp += tocopy;
left -= tocopy;
}
rw_exit(&iostatlist_lock);
return (error);
}
static void
sysctl_io_stats_setup(struct sysctllog **clog)
{
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "hw", NULL,
NULL, 0, NULL, 0,
CTL_HW, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRING, "disknames",
SYSCTL_DESCR("List of disk drives present"),
sysctl_hw_disknames, 0, NULL, 0,
CTL_HW, HW_DISKNAMES, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRING, "iostatnames",
SYSCTL_DESCR("I/O stats are being collected for these"
" devices"),
sysctl_hw_iostatnames, 0, NULL, 0,
CTL_HW, HW_IOSTATNAMES, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRUCT, "iostats",
SYSCTL_DESCR("Statistics on device I/O operations"),
sysctl_hw_iostats, 0, NULL, 0,
CTL_HW, HW_IOSTATS, CTL_EOL);
}