this is called /boot/nextboot.conf. This file is required to have it's first
line be nextboot_enable="YES" for it to be read. Also, this file is
rewritten by the loader to nextboot_enable="NO"<space> after it is read.
This makes it so the file is read exactly once. Finally, the nextboot.conf
is removed shortly after the filesystems are mounted r/w.
Caution should be taken as you can shoot yourself in the foot. This is only
the loader piece. There will be a tool called nextboot(8) that will manage
the nextboot.conf file for you. It is coming shortly.
Reviewed by: dcs
Approved by: jake (mentor)
the last accessed datum is moved to the root of the splay tree.
Therefore, on lookups in which the hint resulted in O(1) access,
the splay tree still achieves O(1) access. In contrast, on lookups
in which the hint failed miserably, the splay tree achieves amortized
logarithmic complexity, resulting in dramatic improvements on vm_maps
with a large number of entries. For example, the execution time
for replaying an access log from www.cs.rice.edu against the thttpd
web server was reduced by 23.5% due to the large number of files
simultaneously mmap()ed by this server. (The machine in question has
enough memory to cache most of this workload.)
Nothing comes for free: At present, I see a 0.2% slowdown on "buildworld"
due to the overhead of maintaining the splay tree. I believe that
some or all of this can be eliminated through optimizations
to the code.
Developed in collaboration with: Juan E Navarro <jnavarro@cs.rice.edu>
Reviewed by: jeff
back to -fformat-extensions (or whatever) when we have the functionality.
We are gaining warnings again that should be fixed but the are being hidden
by NO_WERROR and all the -Wformat noise.
o Use POSIX spelling for types, where possible.
o Define size_t in the __BSD_VISIBLE case (this isn't really needed
for standards conformance, but follows the tradition of not
requiring <sys/types.h> as a prerequisite).
o Use _BYTE_ORDER and friends instead of BYTE_ORDER and friends, since
there may not be enough pollution in order for the latter to work.
o Add an XXX note about the missing IPPROTO_IPV6 macro.
MI API with empty cpu_pause() functions on other arch's, but this
functionality is definitely unique to IA-32, so I decided to leave it
as i386-only and wrap it in #ifdef's. I should have dropped the cpu_
prefix when I made that decision.
Requested by: bde
byte offset of the directory entry for the inode number for all types
of files except directories, although this breaks hard links for
non-directories even if it doesn't cause overflow. Just ignore this
broken inode number for stat() and readdir() and return a less broken
one (the block offset of the file), so that applications normally can't
see the brokenness.
This leaves at least the following brokenness:
- extra inodes, vnodes and caching for hard links.
- various overflow bugs. cd9660 supports 64-bit block numbers, but we
silently ignore the top 32 bits in isonum_733() and then drop another
10 bits for our broken inode numbers. We may also have sign extension
bugs from storing 32-bit extents in ints and longs even if ints are
32-bits. These bugs affect DVDs. mkisofs apparently limits them
by writing directory entries first.
Inode numbers were broken mainly in 4.4BSD-Lite2. FreeBSD-1.1.5 seems
to have a correct implementation modulo the overflow bugs. We need
to look up directory entries from inodes for symlinks only. FreeBSD-1.1.5
use separate fields (iso_parent_extent, iso_parent) to point to the
directory entry. 4.4BSD-Lite doesn't have these, and abuses i_ino to
point to the directory entry. Correct pointers are impossible for
hard links, but symlinks can't be hard links.
