the type argument. This is known to fix some pthread_mutexattr_settype()
invocations, especially when it comes to pulseaudio.
Approved by: kib
deischen (threads)
MFC after: 3 days
- F_READAHEAD: specify the amount for sequential access. The amount is
specified in bytes and is rounded up to nearest block size.
- F_RDAHEAD: Darwin compatible version that use 128KB as the sequential
access size.
A third argument of zero disables the read-ahead behavior.
Please note that the read-ahead amount is also constrainted by sysctl
variable, vfs.read_max, which may need to be raised in order to better
utilize this feature.
Thanks Igor Sysoev for proposing the feature and submitting the original
version, and kib@ for his valuable comments.
Submitted by: Igor Sysoev <is rambler-co ru>
Reviewed by: kib@
MFC after: 1 month
a large page size that is greater than malloc(3)'s default chunk size but
less than or equal to 4 MB, then increase the chunk size to match the large
page size.
Most often, using a chunk size that is less than the large page size is not
a problem. However, consider a long-running application that allocates and
frees significant amounts of memory. In particular, it frees enough memory
at times that some of that memory is munmap()ed. Up until the first
munmap(), a 1MB chunk size is just fine; it's not a problem for the virtual
memory system. Two adjacent 1MB chunks that are aligned on a 2MB boundary
will be promoted automatically to a superpage even though they were
allocated at different times. The trouble begins with the munmap(),
releasing a 1MB chunk will trigger the demotion of the containing superpage,
leaving behind a half-used 2MB reservation. Now comes the real problem.
Unfortunately, when the application needs to allocate more memory, and it
recycles the previously munmap()ed address range, the implementation of
mmap() won't be able to reuse the reservation. Basically, the coalescing
rules in the virtual memory system don't allow this new range to combine
with its neighbor. The effect being that superpage promotion will not
reoccur for this range of addresses until both 1MB chunks are freed at some
point in the future.
Reviewed by: jasone
MFC after: 3 weeks
query umtx also if the shared waiters bit is set on a shared lock.
The writer starvation avoidance technique, infact, can lead to shared
waiters on a shared lock which can bring to a missed wakeup and thus
to a deadlock if the right bit is not checked (a notable case is the
writers counterpart to be handled through expired timeouts).
Fix that by checking for the shared waiters bit also when unlocking the
shared locks.
That bug was causing a reported MySQL deadlock.
Many thanks go to Nick Esborn and his employer DesertNet which provided
time and machines to identify and fix this issue.
PR: thread/135673
Reported by: Nick Esborn <nick at desert dot net>
Tested by: Nick Esborn <nick at desert dot net>
Reviewed by: jeff
needed to satisfy static libraries that are compiled with -fpic
and linked into static binary afterwards. Several libraries in
gcc are examples of such static libs.
EV_RECEIPT is useful to disambiguating error conditions when multiple
events structures are passed to kevent(2). The error code is returned
in the data field and EV_ERROR is set.
Approved by: rwatson (co-mentor)
When the EV_DISPATCH flag is used the event source will be disabled
immediately after the delivery of an event. This is similar to the
EV_ONESHOT flag but it doesn't delete the event.
Approved by: rwatson (co-mentor)
Add user events support to kernel events which are not associated with any
kernel mechanism but are triggered by user level code. This is useful for
adding user level events to an event handler that may also be monitoring
kernel events.
Approved by: rwatson (co-mentor)
An additional one coming from http://www.research.att.com/~gsf/testregex/
was not added; at some point the entire AT&T regression test harness
should be imported here.
But that would also mean commitment to fix the uncovered errors.
PR: 130504
Submitted by: Chris Kuklewicz
API, keeping backward compatibility.
First consumer for this functionality is going to become forthcoming MPD-5.4,
supporting CoA and DR of RFC 3576: Dynamic Authorization Extensions to RADIUS.
MFC after: 1 month
- Add vesa kernel options for amd64.
- Connect libvgl library and splash kernel modules to amd64 build.
- Connect manual page dpms(4) to amd64 build.
- Remove old vesa/dpms files.
Submitted by: paradox <ddkprog yahoo com> [1], swell k at gmail.com
(with some minor tweaks)
in a seperate array. As such we need to use kvm_read rather than bcopy
to populate the ki_groups field.
This fixes a crash when running ps -ax on a coredump.
Reported by: brucec
Tested by: brucec
MFC after: 3 days
(incorrect handling of zero-length reads before the copy buffer is
allocated) is masked by the iso9660 taster. Tar and cpio both enable
that taster so were protected from the bug; unzip is susceptible.
This both fixes the bug and updates the test harness to exercise
this case.
Submitted by: Ed Schouten diagnosed the bug and drafted a patch
MFC after: 7 days
on iso9660 images were returned. While I'm poking around, update
some comments around this area to try to clarify what's going on and
what still remains to be improved.
When I wrote the pseudo-terminal driver for the MPSAFE TTY code, Robert
Watson and I agreed the best way to implement this, would be to let
posix_openpt() create a pseudo-terminal with proper permissions in place
and let grantpt() and unlockpt() be no-ops.
This isn't valid behaviour when looking at the spec. Because I thought
it was an elegant solution, I filed a bug report at the Austin Group
about this. In their last teleconference, they agreed on this subject.
This means that future revisions of POSIX may allow grantpt() and
unlockpt() to be no-ops if an open() on /dev/ptmx (if the implementation
has such a device) and posix_openpt() already do the right thing.
I'd rather put this in the manpage, because simply mentioning we don't
comply to any standard makes it look worse than it is. Right now we
don't, but at least we took care of it.
Approved by: re (kib)
MFC after: 3 days
