From f432014308d6b21386e15affbbca62043615671d Mon Sep 17 00:00:00 2001 From: phk Date: Sat, 15 Mar 2003 21:59:06 +0000 Subject: 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 --- lib/libdevstat/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'lib/libdevstat/Makefile') diff --git a/lib/libdevstat/Makefile b/lib/libdevstat/Makefile index 5d484bf..3c7454e 100644 --- a/lib/libdevstat/Makefile +++ b/lib/libdevstat/Makefile @@ -3,7 +3,8 @@ MAINTAINER=ken@FreeBSD.ORG LIB= devstat -SHLIB_MAJOR= 3 +# Bump DEVSTAT_USER_API_VER in devstat.h every time this is incremented. +SHLIB_MAJOR= 4 SRCS= devstat.c INCS= devstat.h -- cgit v1.1