note that says that this man page is sub-optimal. Bruce Mah should be
happier about this, but someone that groks the cards supported by the
digi driver is encouraged to make this man page suck less.
Instead, allow the mapping to persist, but add the sf_buf to a free list.
If a later sendfile(2) or zero-copy send resends the same physical page,
perhaps with the same or different contents, then the mapping overhead is
avoided and the sf_buf is simply removed from the free list.
In other words, the i386 sf_buf implementation now behaves as a cache of
virtual-to-physical translations using an LRU replacement policy on
inactive sf_bufs. This is similar in concept to a part of
http://www.cs.princeton.edu/~yruan/debox/ patch, but much simpler in
implementation. Note: none of this is required on alpha, amd64, or ia64.
They now use their direct virtual-to-physical mapping to avoid any
emphemeral mapping overheads in their sf_buf implementations.
an int constant to a long constant. This change improves consistency
in the following two ways:
1. The first 8 arguments are always passed in registers on ia64, which
by virtue of the generated code implicitly widens ints to longs and
allows the use of an 32-bit integral type for 64-bit arguments.
Subsequent arguments are passed onto the memory stack, which does
not exhibit the same behaviour and consequently do not allow this.
In practice this means that variadic functions taking pointers
and given NULL (without cast) work as long as the NULL is passed
in one of the first 8 arguments. A SIGSEGV is more likely the
result if such would be done for stack-based arguments. This is
due to the fact that the upper 4 bytes remain undefined.
2. All 64-bit platforms that FreeBSD supports, with the obvious
exception of ia64, allow 32-bit integral types (specifically NULL)
when 64-bit pointers are expected in variadic functions by way of
how the compiler generates code. As such, code that works correctly
(whether rightfully so or not) on any platform other than ia64, may
fail on ia64.
To more easily allow tweaking of the definition of NULL, this commit
removes the 12 definitions in the various headers and puts it in a
new header that can be included whenever NULL is to be made visible.
This commit fixes GNOME, emacs, xemacs and a whole bunch of ports
that I don't particularly care about at this time...
flags. We now create asynchronous contexts or syscall contexts only.
Syscall contexts differ from the minimal ABI dictated contexts by
having the scratch registers saved and restored because that's where
we keep the syscall arguments and syscall return values.
Since this change affects KSE, have it use kse_switchin(2) for the
"new" syscall context.
functions less noisy: We printf if a new function took longer than
the previous record holder, or of the previous record holder took
more than twice as long as the current record.
to have the kernel switch to a new thread, instead of doing it in
userland. It is in fact needed on ia64 where syscall restarts do not
return to userland first. It's completely handled inside the kernel.
As such, any context created by the kernel as part of an upcall and
caused by some syscall needs to be restored by the kernel.
The use of libkvm for post-mortem analysis is still supported (though it
could use more testing). We can now remove vmstat's setgid bit.
While I'm here, hack the interrupt listing code to not display interrupts
that haven't occurred unless the -a option was given on the command line,
and document this change.
Be sure to shift (long)1 << 33 and higher, not (int)1. Otherwise bad
things happen(TM). This is why beast.freebsd.org paniced with ULE.
Reviewed by: jeff
it returns. This allows it to connect to the server side again, which
has been listening on IPv6 addresses exclusively for more than 2 years.
PR: 59369
mutex to be locked. It is redundant since em_init() is called and this
correctly locks the mutex and calls em_stop().
5.2 release candidate since this can cause a panic if the watchdog
expires.
Tested by: kuriyama
