freebsd-skq/lib/libdevstat/Makefile
phk f432014308 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

40 lines
941 B
Makefile

# $FreeBSD$
MAINTAINER=ken@FreeBSD.ORG
LIB= devstat
# Bump DEVSTAT_USER_API_VER in devstat.h every time this is incremented.
SHLIB_MAJOR= 4
SRCS= devstat.c
INCS= devstat.h
DPADD+= ${LIBKVM}
LDADD+= -lkvm
MAN= devstat.3
MLINKS+=devstat.3 devstat_getnumdevs.3
MLINKS+=devstat.3 devstat_getgeneration.3
MLINKS+=devstat.3 devstat_getversion.3
MLINKS+=devstat.3 devstat_checkversion.3
MLINKS+=devstat.3 devstat_getdevs.3
MLINKS+=devstat.3 devstat_selectdevs.3
MLINKS+=devstat.3 devstat_buildmatch.3
MLINKS+=devstat.3 devstat_compute_statistics.3
MLINKS+=devstat.3 devstat_compute_etime.3
MLINKS+=devstat.3 getnumdevs.3
MLINKS+=devstat.3 getgeneration.3
MLINKS+=devstat.3 getversion.3
MLINKS+=devstat.3 checkversion.3
MLINKS+=devstat.3 getdevs.3
MLINKS+=devstat.3 selectdevs.3
MLINKS+=devstat.3 buildmatch.3
MLINKS+=devstat.3 compute_stats.3
MLINKS+=devstat.3 compute_etime.3
CFLAGS+=-I${.CURDIR}
WARNS?= 2
.include <bsd.lib.mk>