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
and compiler warnings.
The data for network statistics are still obtained via the kvm interface
if systat was started with the needed privileges, otherwise sysctls are
used. The reason for this is that with really many open sockets, the
sysctl method is probably slower, but it systat -netstat is probably not
really usable in either mode under these conditions.
Approved by: rwatson
and numvnodes are longs in the kernel. They should remain longs in systat,
what really needs to change is that they should be using SYSCTL_LONG rather
than SYSCTL_INT. I also changed wantfreevnodes to SYSCTL_LONG because I
happened to notice it.
I wish there was a way to find all of these automatically..
Pointed out by: bde
maxvnodes, numvnodes, freevnodes, nchstats, and numdirtybuffers.
o Make the hw.ncpu error checking code a little more rigorous by
sanity checking the returned data size.
o Didn't fix machine-dependent non-sysctl-exported variables:
intrnames, eintrnames, intrcnt, eintrcnt, as these variables are
defined and exported from machine-dependent kernel code in
assembly. This should probably be fixed somehow.
o Add more checks for buffer overflows
o Use snprintf rather than strcat/cpy and have better checks for max
length exceeded.
Most of these changes are not exploitable buffer overruns, but it never
hurts to be safe.
Inspired by and obtained from: OpenBSD
isn't used in systat or in the kernel (it was replaced by a sysctl()
call involving VM_METER) and will go away when I clean up bogus
common variables in the kernel.
I got irritated with not seeing the interrupt numbers in a (crowded)
"systat -vmstat" display, so I fixed it. Here is a patch to please be
applied in src/usr.bin/systat
