implementations can provide a base zero ffs function if they wish.
This changes
#define RQB_FFS(mask) (ffs64(mask))
foo = RQB_FFS(mask) - 1;
to
#define RQB_FFS(mask) (ffs64(mask) - 1)
foo = RQB_FFS(mask);
On some platforms we can get the "- 1" for free, eg: those that use the
C code for ffs64().
Reviewed by: jake (in principle)
Consequently, use vm_map_insert() and vm_map_delete(), which expect
the vm_map to be locked, instead of vm_map_find() and vm_map_remove(),
which do not.
Register the ISR early, but do not actually kick off the timer until we
see some activity. This still saves us from running the arp timers on
a system with no network cards.
- Added a mutex, kld_mtx, to protect the kernel_linker system. Note that
while ``classes'' is global (to that file), it is only read only after
SI_SUB_KLD, SI_ORDER_ANY.
- Add a SYSINIT to flip a flag that disallows class registration after
SI_SUB_KLD, SI_ORDER_ANY.
Idea for ``classes'' read only by: jake
Reviewed by: jake
allocator.
- Properly set M_ZERO when talking to the back end page allocators for
non malloc zones. This forces us to zero fill pages when they are first
brought into a cache.
- Properly handle M_ZERO in uma_zalloc_internal. This fixes a problem where
per cpu buckets weren't always getting zeroed.
expansion of embedded variables in the left-hand-side of an assignment
expression, using the simplest case - hiding recursion using nil-expanded
variables.
seen (somewhat) in NetBSD. This catches a few extra recursion cases that
could be hidden by expanding a NIL variable causing an existing variable to
be returned (which caused infinite looping and climbing memory usage in at
least one case).
Obtained from: NetBSD (in principle)
the second buildworld environment is fully isolated from parent's
environment variables.
Tested virtually on: snapshots.jp.FreeBSD.org
Approved by: arch@ (silently)
MFC after: 2 weeks
reality (and POSIX): current directory isn't searched unless CDPATH has
a "." element or is unset.
PR: 38442
Submitted by: oleg dashevskii <be9@be9.ru>
MFC after: 1 week
in a user process gaining visibility into the 'old' contents of a filesystem
block. There were two cases: (1) when uiomove() fails (user process issues
illegal write), and (2) when uiomove() overlaps a mmap() of the same file at
the same offset (fault -> recursive buffer I/O reads contents of old block).
Unfortunately 1.72 also had the unintended effect of forcing the filesystem
to do a read-before-write in the case of a full-block-write (non append case),
e.g. 'dd if=/dev/zero of=test.dat bs=1m count=256 conv=notrunc'. This
destroys performance.. not only is a read forced for every write, but
clustering breaks as well.
The solution is to clear the buffer manually in the full-block case rather
then asking BALLOC to do it (BALLOC issues the read-before-write). In the
partial-block case we want BALLOC to do it because the read-before-write
is necessary. This patch should greatly improve database and news-feed
server performance.
Found by: MKI <mki@mozone.net>
MFC after: 3 days
executes in the usage() message and manual page. Use "utility" instead of
"command" in both places to emphasise that shell builtins etc. will not work,
and to be consistent with the terminology used by POSIX.
PR: 39210
Submitted by: Danny J. Zerkel <dzerkel@columbus.rr.com>
MFC after: 1 week
uifind() with a proc lock held.
change_ruid() and change_euid() have been modified to take a uidinfo
structure which will be pre-allocated by callers, they will then
call uihold() on the uidinfo structure so that the caller's logic
is simplified.
This allows one to call uifind() before locking the proc struct and
thereby avoid a potential blocking allocation with the proc lock
held.
This may need revisiting, perhaps keeping a spare uidinfo allocated
per process to handle this situation or re-examining if the proc
lock needs to be held over the entire operation of changing real
or effective user id.
Submitted by: Don Lewis <dl-freebsd@catspoiler.org>
release of Giant.
o Reduce the scope of GIANT_REQUIRED in vm_map_insert().
These changes will enable us to remove the acquisition and release
of Giant from obreak().
