the devstat is for an "interior" GEOM node and register using the
name argument as a geom identity pointer. Do not put these devstat
structures on the list returned by the sysctl.
This gives us the ability to tell the two kinds of nodes apart and
leave the current "strictly physical" view of devstat intact without
modifications, yet be able to use devstat for both kinds of devices.
It also saves us bloating struct devstat with another 48 bytes of
space for the name. At least for now.
Reviewed by: ken
Add a mutex and protect the allocation and traversal of the list with it.
When we allocate a page for devstat use we drop the mutex and use
M_WAITOK this is not nice, but under the given circumstances the
best we can do.
In the sysctl handler for returning the devstat entries we do not want to
hold the mutex across copyout(9) calls, so we keep a very careful eye on
the devstat_generation count, and abandon with EBUSY if it changes under
our feet.
Specifically test for BIO_WRITE, rather than default non-read,non-deletes
as write. Make the default be DEVSTAT_NO_DATA.
Add atomic increments of the sequence[01] fields so applications using the
mmap'ed view stand a chance of detecting updates in progress.
Reviewed by: ken
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
is more robust and prevents the hijacking of /dev/console for the typical
mistake.
Remove unneeded MAJOR_AUTO uses, it is only needed explicitly now if the
driver source has cross-branch compatibility to old releases.
the device statistics structures into userland instead of using sysctl.
Introduce new devstat_new_entry() function which allocates the devstat
structure an calls devstat_add_entry() on it.
SYSCTL_LONG macro to be consistent with other integer sysctl variables
and require an initial value instead of assuming 0. Update several
sysctl variables to use the unsigned types.
PR: 15251
Submitted by: Kelly Yancey <kbyanc@posi.net>
<sys/bio.h>.
<sys/bio.h> is now a prerequisite for <sys/buf.h> but it shall
not be made a nested include according to bdes teachings on the
subject of nested includes.
Diskdrivers and similar stuff below specfs::strategy() should no
longer need to include <sys/buf.> unless they need caching of data.
Still a few bogus uses of struct buf to track down.
Repocopy by: peter
devstat_end_transaction_bio()
bioq_* versions of bufq_* incl bioqdisksort()
the corresponding "buf" versions will disappear when no longer used.
Move b_offset, b_data and b_bcount to struct bio.
Add BIO_FORMAT as a hack for fd.c etc.
We are now largely ready to start converting drivers to use struct
bio instead of struct buf.
(Much of this done by script)
Move B_ORDERED flag to b_ioflags and call it BIO_ORDERED.
Move b_pblkno and b_iodone_chain to struct bio while we transition, they
will be obsoleted once bio structs chain/stack.
Add bio_queue field for struct bio aware disksort.
Address a lot of stylistic issues brought up by bde.
field in struct buf: b_iocmd. The b_iocmd is enforced to have
exactly one bit set.
B_WRITE was bogusly defined as zero giving rise to obvious coding
mistakes.
Also eliminate the redundant struct buf flag B_CALL, it can just
as efficiently be done by comparing b_iodone to NULL.
Should you get a panic or drop into the debugger, complaining about
"b_iocmd", don't continue. It is likely to write on your disk
where it should have been reading.
This change is a step in the direction towards a stackable BIO capability.
A lot of this patch were machine generated (Thanks to style(9) compliance!)
Vinum users: Greg has not had time to test this yet, be careful.
Alot of the code in sys/kern directly accesses the *Q_HEAD and *Q_ENTRY
structures for list operations. This patch makes all list operations
in sys/kern use the queue(3) macros, rather than directly accessing the
*Q_{HEAD,ENTRY} structures.
This batch of changes compile to the same object files.
Reviewed by: phk
Submitted by: Jake Burkholder <jake@checker.org>
PR: 14914
WARNING: libdevstat, iostat, vmstat, systat etc etc will need a recompile.
Add devstat_end_transaction_buf() which pulls all the vital data out
of a struct buf which is ready for biodone().
peripheral drivers can determine where in the devstat(9) list they are
inserted.
This requires recompilation of libdevstat, systat, vmstat, rpc.rstatd, and
any ports that depend on the devstat code, since the size of the devstat
structure has changed. The devstat version number has been incremented as
well to reflect the change.
This sorts devices in the devstat list in "more interesting" to "less
interesting" order. So, for instance, da devices are now more important
than floppy drives, and so will appear before floppy drives in the default
output from systat, iostat, vmstat, etc.
The order of devices is, for now, kept in a central table in devicestat.h.
If individual drivers were able to make a meaningful decision on what
priority they should be at attach time, we could consider splitting the
priority information out into the various drivers. For now, though, they
have no way of knowing that, so it's easier to put them in an easy to find
table.
Also, move the checkversion() call in vmstat(8) to a more logical place.
Thanks to Bruce and David O'Brien for suggestions, for reviewing this, and
for putting up with the long time it has taken me to commit it. Bruce did
object somewhat to the central priority table (he would rather the
priorities be distributed in each driver), so his objection is duly noted
here.
Reviewed by: bde, obrien
last cleanup. Since the oid_arg2 field of struct sysctl_oid is not wide
enough to hold a long, the SYSCTL_LONG() macro has been modified to only
support exporting long variables by pointer instead of by value.
Reviewed by: bde
for possible buffer overflow problems. Replaced most sprintf()'s
with snprintf(); for others cases, added terminating NUL bytes where
appropriate, replaced constants like "16" with sizeof(), etc.
These changes include several bug fixes, but most changes are for
maintainability's sake. Any instance where it wasn't "immediately
obvious" that a buffer overflow could not occur was made safer.
Reviewed by: Bruce Evans <bde@zeta.org.au>
Reviewed by: Matthew Dillon <dillon@apollo.backplane.com>
Reviewed by: Mike Spengler <mks@networkcs.com>
devstat_end_transaction error message that gets printed whenever the
busy count is < 0.
This will help catch drivers that improperly implement devstat(9) support.
- Interface wth the new resource manager.
- Allow for multiple drivers implementing a single devclass.
- Remove ordering dependencies between header files.
- Style cleanup.
- Add DEVICE_SUSPEND and DEVICE_RESUME methods.
- Move to a single-phase interrupt setup scheme.
Kernel builds on the Alpha are brken until Doug gets a chance to incorporate
these changes on that side.
Agreed to in principle by: dfr
release goes out the door. We know there's a bug in the devstat
implementation in the wd driver, but bde and msmith haven't been able to
fix it yet.
So, disable the printf to avoid confusing/worrying people.
Suggested by: msmith
help track down bugs in the devstat implementation in various drivers.
(i.e., any situation where the driver does not call the devstat routines
once and only once for each transaction initiation and completion)
Prompted by: msmith
generation was causing unaligned access faults on the Alpha.
I have incremented the devstat version number, since this is an interface
change. You'll need to recompile libdevstat, systat, iostat, vmstat and
rpc.rstatd along with your kernel.
Partially Submitted by: Andrew Gallatin <gallatin@cs.duke.edu>
