freebsd-nq/lib/libdevstat/devstat.h
Poul-Henning Kamp 7194d335cf Run a revision of the devstat interface:
Kernel:

Change statistics to use the *uptime() timescale (ie: relative to
boottime) rather than the UTC aligned timescale.  This makes the
device statistics code oblivious to clock steps.

Change timestamps to bintime format, they are cheaper.

Remove the "busy_count", and replace it with two counter fields:
"start_count" and "end_count", which are updated in the down and
up paths respectively.  This removes the locking constraint on
devstat.

Add a timestamp argument to devstat_start_transaction(), this will
normally be a timestamp set by the *_bio() function in bp->bio_t0.
Use this field to calculate duration of I/O operations.

Add two timestamp arguments to devstat_end_transaction(), one is
the current time, a NULL pointer means "take timestamp yourself",
the other is the timestamp of when this transaction started (see
above).

Change calculation of busy_time to operate on "the salami principle":
Only when we are idle, which we can determine by the start+end
counts being identical, do we update the "busy_from" field in the
down path.  In the up path we accumulate the timeslice in busy_time
and update busy_from.

Change the byte_* and num_* fields into two arrays: bytes[] and
operations[].

Userland:

Change the misleading "busy_time" name to be called "snap_time" and
make the time long double since that is what most users need anyway,
fill it using clock_gettime(CLOCK_MONOTONIC) to put it on the same
timescale as the kernel fields.

Change devstat_compute_etime() to operate on struct bintime.

Remove the version 2 legacy interface: the change to bintime makes
compatibility far too expensive.

Fix a bug in systat's "vm" page where boot relative busy times would
be bogus.

Bump __FreeBSD_version to 500107

Review & Collaboration by:	ken
2003-03-15 21:59:06 +00:00

158 lines
4.7 KiB
C

/*
* 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.
*
* $FreeBSD$
*/
#ifndef _DEVSTAT_H
#define _DEVSTAT_H
#include <sys/cdefs.h>
#include <sys/devicestat.h>
#include <kvm.h>
/*
* Bumped every time we change the userland API. Hopefully this doesn't
* happen very often! This should be bumped every time we have to
* increment SHLIB_MAJOR in the libdevstat Makefile (for non-backwards
* compatible API changes) and should also be bumped every time we make
* backwards-compatible API changes, so application writers have a way to
* determine when a particular feature is available.
*/
#define DEVSTAT_USER_API_VER 4
#define DEVSTAT_ERRBUF_SIZE 2048 /* size of the devstat library error string */
extern char devstat_errbuf[];
typedef enum {
DEVSTAT_MATCH_NONE = 0x00,
DEVSTAT_MATCH_TYPE = 0x01,
DEVSTAT_MATCH_IF = 0x02,
DEVSTAT_MATCH_PASS = 0x04
} devstat_match_flags;
typedef enum {
DSM_NONE,
DSM_TOTAL_BYTES,
DSM_TOTAL_BYTES_READ,
DSM_TOTAL_BYTES_WRITE,
DSM_TOTAL_TRANSFERS,
DSM_TOTAL_TRANSFERS_READ,
DSM_TOTAL_TRANSFERS_WRITE,
DSM_TOTAL_TRANSFERS_OTHER,
DSM_TOTAL_BLOCKS,
DSM_TOTAL_BLOCKS_READ,
DSM_TOTAL_BLOCKS_WRITE,
DSM_KB_PER_TRANSFER,
DSM_KB_PER_TRANSFER_READ,
DSM_KB_PER_TRANSFER_WRITE,
DSM_TRANSFERS_PER_SECOND,
DSM_TRANSFERS_PER_SECOND_READ,
DSM_TRANSFERS_PER_SECOND_WRITE,
DSM_TRANSFERS_PER_SECOND_OTHER,
DSM_MB_PER_SECOND,
DSM_MB_PER_SECOND_READ,
DSM_MB_PER_SECOND_WRITE,
DSM_BLOCKS_PER_SECOND,
DSM_BLOCKS_PER_SECOND_READ,
DSM_BLOCKS_PER_SECOND_WRITE,
DSM_MS_PER_TRANSACTION,
DSM_MS_PER_TRANSACTION_READ,
DSM_MS_PER_TRANSACTION_WRITE,
DSM_SKIP,
DSM_MAX
} devstat_metric;
struct devstat_match {
devstat_match_flags match_fields;
devstat_type_flags device_type;
int num_match_categories;
};
struct devstat_match_table {
const char * match_str;
devstat_type_flags type;
devstat_match_flags match_field;
};
struct device_selection {
u_int32_t device_number;
char device_name[DEVSTAT_NAME_LEN];
int unit_number;
int selected;
u_int64_t bytes;
int position;
};
struct devinfo {
struct devstat *devices;
u_int8_t *mem_ptr;
long generation;
int numdevs;
};
struct statinfo {
long cp_time[CPUSTATES];
long tk_nin;
long tk_nout;
struct devinfo *dinfo;
long double snap_time;
};
typedef enum {
DS_SELECT_ADD,
DS_SELECT_ONLY,
DS_SELECT_REMOVE,
DS_SELECT_ADDONLY
} devstat_select_mode;
__BEGIN_DECLS
int devstat_getnumdevs(kvm_t *kd);
long devstat_getgeneration(kvm_t *kd);
int devstat_getversion(kvm_t *kd);
int devstat_checkversion(kvm_t *kd);
int devstat_getdevs(kvm_t *kd, struct statinfo *stats);
int devstat_selectdevs(struct device_selection **dev_select, int *num_selected,
int *num_selections, long *select_generation,
long current_generation, struct devstat *devices,
int numdevs, struct devstat_match *matches,
int num_matches, char **dev_selections,
int num_dev_selections, devstat_select_mode select_mode,
int maxshowdevs, int perf_select);
int devstat_buildmatch(char *match_str, struct devstat_match **matches,
int *num_matches);
int devstat_compute_statistics(struct devstat *current,
struct devstat *previous,
long double etime, ...);
long double devstat_compute_etime(struct bintime *cur_time,
struct bintime *prev_time);
__END_DECLS
#endif /* _DEVSTAT_H */