of the number of threads which are inside whatever is behind the
cdevsw for this particular cdev.
Make the device mutex visible through dev_lock() and dev_unlock().
We may want finer granularity later.
Replace spechash_mtx use with dev_lock()/dev_unlock().
A thread must hold mp while calling cv_signal(), cv_broadcast(), or
cv_broadcastpri() even though it isn't passed as an argument.
and is right with this claim.
While here remove a "\" from the macro -> __inline conversion.
Found by: csjp
MFC after: 4 days
old or previous value instead of void. This is not as is documented
in atomic(9), but is API (and ABI) compatible and simply makes sense.
This feature will primarily be used for atomic PTE updates in PMAP/ng.
was seen when configuring addresses on interfaces using ifconfig. This
patch has been verified to work with over eight thousand addresses
assigned to an interface.
LOR id: 031
panic on hub detach bugs that have been reported. This work around
detaches the device before deleting it. This changes the detach order
from in-order to pre-order. This avoids uhub's deleting the children
after its subdevs has been deleted.
This is only a workaround. This leads to a strange condition in the
device tree where attached devices are children of detached ones. I
really don't know what that's supposed to mean, but does violate my
sense of POLA. Fortunately, the violation is short lived, which is
why I'm going ahead and committing the work around.
# We really need to consider life w/o the multiple nested layers of
# compatibility macros. They make finding bugs like this *MUCH*
# harder.
Patch by: iadowse
MT5 before: next_release(5.3-BETA5) (unless someting better comes along)
multiprocessors. Specifically, the error is conditioning the call to
pmap_invalidate_page() on whether the pmap is active on the current CPU.
This call must be unconditional. Regardless of whether the pmap is active
on the CPU performing _pmap_unwire_pte_hold(), it could be active on another
CPU. For example, a call to pmap_remove_all() by the page daemon could
result in a call to _pmap_unwire_pte_hold() with the pmap inactive on the
current CPU and active on another CPU. In such circumstances, failing to
call pmap_invalidate_page() results in a stale TLB entry on the other CPU
that still maps the now deallocated page table page. What happens next is
typically a mysterious panic in pmap_enter() by the other CPU, either
"pmap_enter: attempted pmap_enter on 4MB page" or "pmap_enter: pte vanished,
va: 0x%lx". Both occur because the former page table page has been recycled
and allocated to a new purpose. Consequently, it no longer contains zeroes.
See also Peter's i386/i386/pmap.c revision 1.448 and the related e-mail
thread last year.
Many thanks to the engineers at Sandvine for providing clear and concise
information until all of the pieces of the puzzle fell into place and
for testing an earlier patch.
MT5 Candidate
Better to kill all other threads than to panic the system if 2 threads call
execve() at the same time. A better fix will be committed later.
Note that this only affects the case where the execve fails.
a stack trace from ddb, the output will pause with a '--More--' prompt
every 18 lines. If you hit Enter, it will print another line and prompt
again. If you hit space it will output another page and then prompt.
If you hit 'q' or 'x' it will abort the rest of the stack trace.
- Fix the sparc64 userland stack trace to honor the total count of lines
to print. This is useful if your trace happens to walk back onto
0xdeadc0de and gets stuck in an endless loop.
MFC after: 1 month
Tested on: i386, alpha, sparc64
Actually, it can even cause some problems, because GEOM requires sectorsize
to be more than 0 on first access, not on provider creation, so we can skip
valid providers by doing this check here.
Reported by: Divacky Roman <xdivac02@stud.fit.vutbr.cz>
Sven Willenberger <sven@dmv.com>
Ask uma_zcreate() to align mbufs to MSIZE bytes (otherwise dtom() breaks)
As it happens, uma_zalloc_arg() always returned mbufs aligned to MSIZE
anyway, but that was an implementation side-effect....
KASSERT -> CTASSERT suggested by: dd@
Approved by: silence on -net
and 0x3f7. fdc_isa_alloc_resource() didn't work right in this case
(it accessed FDOUT correctly due to an overflow of the first resource.
It accesed FDSTS and FDDATA incorrectly via the second resource (which
wound up accessing FDOUT and the tape register at 0x3f3) and badly for
the CTL register (at location 0x3f4). This is a minimal fix that just
'eats' the first one if it covers two locations and has an offset of
0. This confusion lead the floppy driver to think there'd been a disk
change, which uncovered a deadlock in the floppy/geom code which lead
to a panic. These changes fix that by fixing the underlying resource
problem, but doesn't address the potential deadlock issue that might
still be there.
This is a minimal fix so it can more safely be merged into 5 w/o risk
for known working configurations (hence the use of the ugly goto,
which reduces case 8 to case 6 w/o affecting cases 1-7). A more
invasive fix that will handle more ACPI resource list diversity is in
the pipeline that should kill these issues once and for all, while
staying within the resources that we allocate.
Tested/Reported by: das
Reviewed by: njl
MFC before: re->next_release_name(5.3-BETA5);
registers are control bits or depending on the model contain additional
time bits with a different meaning than the lower ones. In order to
only read the desired time bits and not change the upper bits on write
use appropriate masks in the gettime and settime function respectively.
Due to the polarity of the stop oscillator bit and the fact that the
century bits aren't used on sparc64 not masking them didn't cause
problems so far.
- Fix two off-by-one errors in the handling of the day of week. The
genclock code represents the dow as 0 - 6 with 0 being Sunday but the
mk48txx use 1 - 7 with 1 being Sunday. In the settime function when
writing the dow to the clock the range wasn't adjusted accordingly but
the clock apparently played along nicely otherwise the second bug in
the gettime function which mapped 1 - 7 to 0 - 6 but with 0 meaning
Saturday would have been triggered. Fixing these makes the date being
stored in the same format Sun/Solaris uses and cures the "Invalid time
in real time clock. Check and reset the date immediately!" when the
date was set under Solaris prior to booting FreeBSD/sparc64. [1]
Looking at other clock drivers/code e.g. FreeBSD/alpha the former "bug",
i.e. storing the dow as 0 - 6 even when the clock uses 1 - 7, seems to
be common but might be on purpose for compatibility when multi-booting
with other OS which do the same. So it might make sense to add a flag
to handle the dow off-by-one for use of this driver on platforms other
than sparc64.
- Check the state of the battery on mk48txx that support this in the
attach function.
- Add a note that use of the century bit should be implemented but isn't
required at the moment because it isn't used on sparc64.
Problem noted by: joerg [1]
MT5 candidate.
the page table page's wired count rather than its hold count to contain
the reference count. My rationale for this change is based on several
factors:
1. The machine-independent and pmap layers used the same hold count field
in subtly different ways. The machine-independent layer uses the hold
count to implement a form of ephemeral wiring that is used by pipes,
physio, etc. In other words, subsystems where we wish to temporarily
block a page from being swapped out while it is mapped into the kernel's
address space. Such pages are never removed from the page queues.
Instead, the page daemon recognizes a non-zero hold count to mean "hands
off this page." In contrast, page table pages are never in the page
queues; they are wired from birth to death. The hold count was being
used as a kind of reference count, specifically, the number of valid
page table entries within the page. Not surprisingly, these two
different uses imply different synchronization rules: in the machine-
independent layer access to the hold count requires the page queues
lock; whereas in the pmap layer the pmap lock is required. Thus,
continued use by the pmap layer of vm_page_unhold(), which asserts that
the page queues lock is held, made no sense.
2. _pmap_unwire_pte_hold() was too forgiving in its handling of the wired
count. An unexpected wired count on a page table page was ignored and
the underlying page leaked.
3. In a word, microoptimization. Using the wired count exclusively, rather
than a combination of the wired and hold counts, makes the code slightly
smaller and faster.
Reviewed by: tegge@
UMA_ZONE_NOFREE to guarantee type stability, so proc_fini() should
never be called. Move an assertion from proc_fini() to proc_dtor()
and garbage-collect the rest of the unreachable code. I have retained
vm_proc_dispose(), since I consider its disuse a bug.
too much kernel copying, but it is not the right way to do it, and it is
in the way for straightening out the buffer cache.
The right way is to pass the VM page array down through the struct
bio to the disk device driver and DMA directly in to/out off the
physical memory. Once the VM/buf thing is sorted out it is next on
the list.
Retire most of vnode method. ffs_getpages(). It is not clear if what is
left shouldn't be in the default implementation which we now fall back to.
Retire specfs_getpages() as well, as it has no users now.
