o Use 8 space hard tabs
o Eliminate trailing white space (while I'm here, just in a couple of places)
o wrap mostly at 80 columns (printf literal strings being the notable
exception)
o use return (foo) consistantly
o use 0 vs NULL more consistantly
o use queue(3) xxx_FOREACH macros where appropriate (some places used it
before, others didn't).
o use BSD line continuation parameters
Pendants will likely notice minor style(9) violations, but for the
most part the file now looks much much closer to style(9) and is
mostly self-consistant.
Approved in principle by: dfr
Reviewed by: md5 (no changes to the .o)
to the SYSCTL_ADD_FOO() macros is a constant that should be turned into
a string via the pre-processor. Instead, require it to be an explicit
string so that names can be generated on the fly.
- Make some of the char * arguments to sysctl_add_oid() const to quiet
warnings.
file.
While there fix the layout of function headers (noticable in long headers)
Fix up some style nits. It's Perl and should be written in that style.
out: label in psignal() did not grab sched_lock before trying to release
it. Also, the previous version had several cases where it grabbed
sched_lock before jumping to out: unneccessarily, so rework this a bit.
The runfast: and out: labels must be called with sched_lock released, and
the run: label must be called with it held. Appropriate mtx_assert()'s
have been added that should catch any bugs that may still be in this
code.
Noticed by: bde
attaching to running processes, it completely breaks normal debugging.
A better fix is in the works, but cannot be properly tested until
the problem with gdb hanging the system in -current is solved.
process. This fixes a problem when attaching to a process in gdb
and the process staying in the STOP'd state after quiting gdb.
This whole process seems a bit suspect, but this seems to work.
Reviewed by: peter
in 4.2-REL which I ripped out in -stable and -current when implementing the
low-memory handling solution. However, maxlaunder turns out to be the saving
grace in certain very heavily loaded systems (e.g. newsreader box). The new
algorithm limits the number of pages laundered in the first pageout daemon
pass. If that is not sufficient then suceessive will be run without any
limit.
Write I/O is now pipelined using two sysctls, vfs.lorunningspace and
vfs.hirunningspace. This prevents excessive buffered writes in the
disk queues which cause long (multi-second) delays for reads. It leads
to more stable (less jerky) and generally faster I/O streaming to disk
by allowing required read ops (e.g. for indirect blocks and such) to occur
without interrupting the write stream, amoung other things.
NOTE: eventually, filesystem write I/O pipelining needs to be done on a
per-device basis. At the moment it is globalized.
This is because calls with M_WAIT (now M_TRYWAIT) may not wait
forever when nothing is available for allocation, and may end up
returning NULL. Hopefully we now communicate more of the right thing
to developers and make it very clear that it's necessary to check whether
calls with M_(TRY)WAIT also resulted in a failed allocation.
M_TRYWAIT basically means "try harder, block if necessary, but don't
necessarily wait forever." The time spent blocking is tunable with
the kern.ipc.mbuf_wait sysctl.
M_WAIT is now deprecated but still defined for the next little while.
* Fix a typo in a comment in mbuf.h
* Fix some code that was actually passing the mbuf subsystem's M_WAIT to
malloc(). Made it pass M_WAITOK instead. If we were ever to redefine the
value of the M_WAIT flag, this could have became a big problem.
point in calling a function just to set a flag.
Keep better track of the syslog FAC/PRI code and try to DTRT if
they mingle.
Log all writes to /dev/console to syslog with <console.info>
priority. The formatting is not preserved, there is no robust,
way of doing it. (Ideas with patches welcome).
the kernel console. Instead, change logwakeup() to set a flag in the
softc. A callout then wakes up every so often and wakes up any processes
selecting on /dev/log (such as syslogd) if the flag is set. By default
this callout fires 5 times a second, but that can be adjusted by the
sysctl kern.log_wakeups_per_second.
Reviewed by: phk
commands have also been slightly updated as follows:
- Use ktr_idx to find the newest entry rather than walking the buffer
comparing timespecs. Timespecs are not always unique after the change
to use getnanotime(9).
- Add a new verbose setting. When the verbose setting is on, then the
timestamp is printed with each message. If KTR_EXTEND is on, then the
filename and line number are output as well. By default this option is
off. It can be turned on with the 'v' modifier passed to the 'tbuf'
and 'tall' commands. For the 'tnext' command, the 'v' modifier toggles
the verbose mode.
- Only display the cpu number for each message on SMP systems.
- Don't display anything for an empty entry that hasn't been used yet.
functions. If this flag is set, then no KTR log messages are issued.
This is useful for blocking excessive logging, such as with the internal
mutex used by the witness code.
- Use MTX_QUIET on all of the mtx_enter/exit operations on the internal
mutex used by the witness code.
- If we are in a panic, don't do witness checks in witness_enter(),
witness_exit(), and witness_try_enter(), just return.
vm86_trap() to return to the calling program directly. vm86_trap()
doesn't return, thus it was never returning to trap() to release
Giant. Thus, release Giant before calling vm86_trap().
of explicit calls to lockmgr. Also provides macros for the flags
pased to specify shared, exclusive or release which map to the
lockmgr flags. This is so that the use of lockmgr can be easily
replaced with optimized reader-writer locks.
- Add some locking that I missed the first time.
no longer contains kernel specific data structures, but rather
only scalar values and structures that are already part of the
kernel/user interface, specifically rusage and rtprio. It no
longer contains proc, session, pcred, ucred, procsig, vmspace,
pstats, mtx, sigiolst, klist, callout, pasleep, or mdproc. If
any of these changed in size, ps, w, fstat, gcore, systat, and
top would all stop working. The new structure has over 200 bytes
of unassigned space for future values to be added, yet is nearly
100 bytes smaller per entry than the structure that it replaced.
be safely held across an eventhandler function call.
- Fix an instance of the head of an eventhandler list being read without
the lock being held.
- Break down and use a SYSINIT at the new SI_SUB_EVENTHANDLER to initialize
the eventhandler global mutex and the eventhandler list of lists rather
than using a non-MP safe initialization during the first call to
eventhandler_register().
- Add in a KASSERT() to eventhandler_register() to ensure that we don't try
to register an eventhandler before things have been initialized.
held and panic if so (conditional on witness).
- Change witness_list to return the number of locks held so this is easier.
- Add kern/syscalls.c to the kernel build if witness is defined so that the
panic message can contain the name of the offending system call.
- Add assertions that Giant and sched_lock are not held when returning from
a system call, which were missing for alpha and ia64.
can lead to further panics.
- Call getnanotime() instead of nanotime() for the timestamp. nanotime()
is more precise, but it also calls into the timer code, which results
in mutex operations on the i386 arch. If KTR_LOCK is turned on, then
ktr_tracepoint() recurses on itself until it exhausts the kernel stack.
Eventually this should change to use get_cyclecount() instead, but that
can't happen if get_cyclecount() is calling nanotime() instead of
getnanotime().
