Since we are using vfs_busy() on a freshly allocated mount structure, use
(void) to show that we do not care about the return value.
Found with: Coverity Prevent (tm)
MFC after: 2 weeks
taskqueue_start_threads(struct taskqueue **, int count, int pri,
const char *name, ...);
This allows the creation of 1 or more threads that will service a single
taskqueue. Also rework the taskqueue_create() API to remove the API change
that was introduced a while back. Creating a taskqueue doesn't rely on
the presence of a process structure, and the proc mechanics are much better
encapsulated in taskqueue_start_threads(). Also clean up the
taskqueue_terminate() and taskqueue_free() functions to safely drain
pending tasks and remove all associated threads.
The TASKQUEUE_DEFINE and TASKQUEUE_DEFINE_THREAD macros have been changed
to use the new API, but drivers compiled against the old definitions will
still work. Thus, recompiling drivers is not a strict requirement.
intended for use solely with atomic datagram socket types, and relies
on the previous break-out of sosend_copyin(). Changes to allow UDP to
optionally use this instead of sosend() will be committed as a
follow-up.
to COMPAT_43TTY.
Add COMPAT_43TTY to NOTES and */conf/GENERIC
Compile tty_compat.c only under the new option.
Spit out
#warning "Old BSD tty API used, please upgrade."
if ioctl_compat.h gets #included from userland.
fast taskqueues. The following have been added:
TASKQUEUE_FAST_DEFINE() - create a global task queue.
an arbitrary execution context.
TASKQUEUE_FAST_DEFINE_THREAD() - create a global taskqueue that uses a
dedicated kthread.
taskqueue_create_fast() - create a local/private taskqueue.
These are all complimentary of the standard taskqueue functions. They are
primarily useful for fast interrupt handlers that can only use spinlock for
synchronization.
I personally think that the taskqueue API is starting to get too narrow and
hairy, but fixing it will require a major redesign on the API. Such a
redesign would be good but would break compatibility with FreeBSD 6.x, so
it really isn't desirable at this time.
Submitted by: sam
and subsequently broke the build. This change is supposed to fix the
case where doing a mtx_destroy() off a spin mutex while you hold it fails.
If it had been tested I would just leave it in, but it hasn't been tested
yet, so it will have to wait until later.
struct sx). Instead of storing a direct pointer to a our lock_class
struct in lock_object, reserve 4 bits in the lo_flags field to serve as an
index into a global lock_classes array that contains pointers to the lock
classes. Only debugging code such as WITNESS or INVARIANTS checks and KTR
logging need to access the lock_class member, so this shouldn't add any
overhead to production kernels. It might add some slight overhead to
kernels using those debug options however.
As with the previous set of changes to lock_object, this is going to
completely obliterate the kernel ABI, so be sure to recompile all your
modules.
returns EBADF. That errno is correct and is mandated by POSIX. It also
goes back to revision 1.1 of our CVS history (i.e. 4.4BSD).
The _fget() function should probably also be upated as it currently returns
EINVAL in that case rather than EBADF. (It does return EBADF for reads
on a write-only descriptor without any XXX comments oddly enough.)
Discussed with: scottl, grog, mjacob, bde
that a file's atime and mtime are only set to correct fractional
second values (0-999999000ns with the current interface).
Prior to this change users could create files with values outside
that range. Moreover, on 32-bit machines tv_usec offsets larger than
4.3s would result in an unnormalized AND wrong timestamp value,
due to overflow.
MFC after: 1 week
- provide an interface (macros) to the page coloring part of the VM system,
this allows to try different coloring algorithms without the need to
touch every file [1]
- make the page queue tuning values readable: sysctl vm.stats.pagequeue
- autotuning of the page coloring values based upon the cache size instead
of options in the kernel config (disabling of the page coloring as a
kernel option is still possible)
MD changes:
- detection of the cache size: only IA32 and AMD64 (untested) contains
cache size detection code, every other arch just comes with a dummy
function (this results in the use of default values like it was the
case without the autotuning of the page coloring)
- print some more info on Intel CPU's (like we do on AMD and Transmeta
CPU's)
Note to AMD owners (IA32 and AMD64): please run "sysctl vm.stats.pagequeue"
and report if the cache* values are zero (= bug in the cache detection code)
or not.
Based upon work by: Chad David <davidc@acns.ab.ca> [1]
Reviewed by: alc, arch (in 2004)
Discussed with: alc, Chad David, arch (in 2004)
- Provide tunable vm.memguard.desc, so one can specify memory type without
changing the code and recompiling the kernel.
- Allow to use memguard for kernel modules by providing sysctl
vm.memguard.desc, which can be changed to short description of memory
type before module is loaded.
- Move as much memguard code as possible to memguard.c.
- Add sysctl node vm.memguard. and move memguard-specific sysctl there.
- Add malloc_desc2type() function for finding memory type based on its
short description (ks_shortdesc field).
- Memory type can be changed (via vm.memguard.desc sysctl) only if it
doesn't exist (will be loaded later) or when no memory is allocated yet.
If there is allocated memory for the given memory type, return EBUSY.
- Implement two ways of memory types comparsion and make safer/slower the
default.
The race is very real, but conditions needed for triggering it are rather
hard to meet now.
When gjournal will be committed (where it is quite easy to trigger) we need
to fix it.
For now, verify if it is really hard to trigger.
Discussed with: kan
of msleep(). msleep_spin() doesn't support changing the priority of the
thread while it is asleep nor does it support interruptible sleeps (PCATCH)
or the PDROP flag. It does support timeouts however. It differs from
msleep() in that the passed in mutex is a spin mutex. This means one can
use msleep_spin() and wakeup() with a spin mutex similar to msleep() and
wakeup() with a regular mutex. Note that the spin mutex in question needs
to come before sched_lock and the sleepq locks in lock order.
spin locks that are not in the static order list. It is not safe to call
printf while holding the witness spin mutex since the console drivers that
back printf may need to use their own spin locks which would try to talk
to witness when they were locked. Given this, it is possible for one
CPU to lock a console driver lock (such as sio) which then tries to lock
the witness lock while another CPU is doing the printf while holding the
witness lock. Fix this by moving the printf outside of the witness lock.
All other printf's in witness are already correct.
MFC after: 3 days
UMA_SLAB_MALLOC flag.
In some circumstances (I observed it when I was doing a lot of reallocs)
UMA_SLAB_MALLOC can be set even if us_keg != NULL.
If this is the case we have wonderful, silent data corruption, because less
data is copied to the newly allocated region than should be.
I'm not sure when this bug was introduced, it could be there undetected
for years now, as we don't have a lot of realloc(9) consumers and it was
hard to reproduce it...
...but what I know for sure, is that I don't want to know who introduce
the bug:) It took me two/three days to track it down (of course most of
the time I was looking for the bug in my own code).
with flags bitfield and set BI_CAN_EXEC_DYN flag for all brands that usually
allow executing elf dynamic binaries (aka shared libraries). When it is
requested to execute ET_DYN elf image check if this flag is on after we
know the elf brand allowing execution if so.
PR: kern/87615
Submitted by: Marcin Koziej <creep@desk.pl>
Specifically, it is required for the I/O that may be performed by
elfN_load_section().
Avoid an obscure deadlock in the a.out, elf, and gzip image
activators. Add a comment describing why the deadlock does not occur
in the common case and how it might occur in less usual circumstances.
Eliminate an unused variable from exec_aout_imgact().
In collaboration with: tegge
by debugger, e.g process is dumping core. Only access p_xthread if
P_STOPPED_TRACE is set, this means thread is ready to exchange signal
with debugger, print a warning if P_STOPPED_TRACE is not set due to
some bugs in other code, if there is.
The patch has been tested by Anish Mistry mistry.7 at osu dot edu, and
is slightly adjusted.
