freebsd kernel with SKQ
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Konstantin Belousov c480f781ea Current implementations of sync(2) and syncer vnode fsync() VOP uses
mnt_noasync counter to temporary remove MNTK_ASYNC mount option, which
is needed to guarantee a synchronous completion of the initiated i/o
before syscall or VOP return.  Global removal of MNTK_ASYNC option is
harmful because not only i/o started from corresponding thread becomes
synchronous, but all i/o is synchronous on the filesystem which is
initiated during sync(2) or syncer activity.

Instead of removing MNTK_ASYNC from mnt_kern_flag, provide a local
thread flag to disable async i/o for current thread only. Use the
opportunity to move DOINGASYNC() macro into sys/vnode.h and
consistently use it through places which tested for MNTK_ASYNC.

Some testing demonstrated 60-70% improvements in run time for the
metadata-intensive operations on async-mounted UFS volumes, but still
with great deviation due to other reasons.

Reviewed by:	mckusick
Tested by:	scottl
MFC after:	2 weeks
2012-02-06 11:04:36 +00:00
bin sh: Fix swapped INTON/INTOFF. 2012-02-04 23:29:07 +00:00
cddl Set SVN text/plain property for some shell scripts that 2012-01-28 00:17:17 +00:00
contrib Add a WITH_CLANG_EXTRAS option for src.conf(5), disabled by default, 2012-02-05 23:56:22 +00:00
crypto Fix a problem whereby a corrupt DNS record can cause named to crash. [11:06] 2011-12-23 15:00:37 +00:00
etc Fix $ipv6_network_interfaces handling in rc.d/routing. It could fail when 2012-02-04 18:14:49 +00:00
games o Preserve argv[0] to use it later in usage(). 2012-01-28 15:29:43 +00:00
gnu Adopt to new layout of struct pcb. 2012-01-21 17:50:14 +00:00
include Only use the static assertion when __generic is available. 2012-01-17 20:22:10 +00:00
kerberos5 Don't support OpenLDAP during lib32 build. 2011-12-06 12:03:01 +00:00
lib Add a WITH_CLANG_EXTRAS option for src.conf(5), disabled by default, 2012-02-05 23:56:22 +00:00
libexec Add support for GNU RELRO. 2012-01-30 19:52:17 +00:00
release Fix installation script after r230482 -- a missing character apparently. 2012-02-04 23:00:27 +00:00
rescue -lreadline is not required anymore. 2011-11-29 03:27:09 +00:00
sbin If a local write request is from the synchronization thread, when it 2012-02-05 15:23:32 +00:00
secure Force linker error when created shared library contains a relocation 2011-12-06 11:28:17 +00:00
share Add a WITH_CLANG_EXTRAS option for src.conf(5), disabled by default, 2012-02-05 23:56:22 +00:00
sys Current implementations of sync(2) and syncer vnode fsync() VOP uses 2012-02-06 11:04:36 +00:00
tools Add fixwhite(1). 2012-02-06 10:23:11 +00:00
usr.bin Add a WITH_CLANG_EXTRAS option for src.conf(5), disabled by default, 2012-02-05 23:56:22 +00:00
usr.sbin Be as explicit as possible when describing relation between the -m mask 2012-02-04 13:12:52 +00:00
COPYRIGHT Happy 2012 to FreeBSD users in Samoa. 2011-12-31 04:38:04 +00:00
LOCKS
MAINTAINERS Add isci(4) driver for amd64 and i386 targets. 2012-01-31 19:38:18 +00:00
Makefile Replace 'chflags' with 'file flags' in a comment, since 'chflags' 2011-11-20 20:05:47 +00:00
Makefile.inc1 Allow specification of build shell for the buildenv target. 2012-01-30 20:19:28 +00:00
Makefile.mips Retire TARGET_ABI. 2011-01-07 20:26:33 +00:00
ObsoleteFiles.inc Remove wtmpcvt(1). 2012-01-13 15:40:49 +00:00
README Add the cddl/ directory. 2010-11-14 11:32:56 +00:00
UPDATING For the mass rc.d changes, add a command line to make the update easier 2012-01-14 23:19:10 +00:00

This is the top level of the FreeBSD source directory.  This file
was last revised on:
$FreeBSD$

For copyright information, please see the file COPYRIGHT in this
directory (additional copyright information also exists for some
sources in this tree - please see the specific source directories for
more information).

The Makefile in this directory supports a number of targets for
building components (or all) of the FreeBSD source tree, the most
commonly used one being ``world'', which rebuilds and installs
everything in the FreeBSD system from the source tree except the
kernel, the kernel-modules and the contents of /etc.  The ``world''
target should only be used in cases where the source tree has not
changed from the currently running version.  See:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html
for more information, including setting make(1) variables.

The ``buildkernel'' and ``installkernel'' targets build and install
the kernel and the modules (see below).  Please see the top of
the Makefile in this directory for more information on the
standard build targets and compile-time flags.

Building a kernel is a somewhat more involved process, documentation
for which can be found at:
   http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html
And in the config(8) man page.
Note: If you want to build and install the kernel with the
``buildkernel'' and ``installkernel'' targets, you might need to build
world before.  More information is available in the handbook.

The sample kernel configuration files reside in the sys/<arch>/conf
sub-directory (assuming that you've installed the kernel sources), the
file named GENERIC being the one used to build your initial installation
kernel.  The file NOTES contains entries and documentation for all possible
devices, not just those commonly used.  It is the successor of the ancient
LINT file, but in contrast to LINT, it is not buildable as a kernel but a
pure reference and documentation file.


Source Roadmap:
---------------
bin		System/user commands.

cddl		Various commands and libraries under the Common Development
		and Distribution License.

contrib		Packages contributed by 3rd parties.

crypto		Cryptography stuff (see crypto/README).

etc		Template files for /etc.

games		Amusements.

gnu		Various commands and libraries under the GNU Public License.
		Please see gnu/COPYING* for more information.

include		System include files.

kerberos5	Kerberos5 (Heimdal) package.

lib		System libraries.

libexec		System daemons.

release		Release building Makefile & associated tools.

rescue		Build system for statically linked /rescue utilities.

sbin		System commands.

secure		Cryptographic libraries and commands.

share		Shared resources.

sys		Kernel sources.

tools		Utilities for regression testing and miscellaneous tasks.

usr.bin		User commands.

usr.sbin	System administration commands.


For information on synchronizing your source tree with one or more of
the FreeBSD Project's development branches, please see:

  http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html