proper parens mean that fd is always set by open(2) [in any part of C],
and so we can accurately check for it returning -1, without feeling like
we need to initialise fd to -1 in its declaration.
In other words, fix a stylistic/bogus nit.
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
