freebsd_amp_hwpstate

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Christian S.J. Peron 4d621040ff Introduce support for zero-copy BPF buffering, which reduces the overhead of packet capture by allowing a user process to directly "loan" buffer memory to the kernel rather than using read(2) to explicitly copy data from kernel address space. The user process will issue new BPF ioctls to set the shared memory buffer mode and provide pointers to buffers and their size. The kernel then wires and maps the pages into kernel address space using sf_buf(9), which on supporting architectures will use the direct map region. The current "buffered" access mode remains the default, and support for zero-copy buffers must, for the time being, be explicitly enabled using a sysctl for the kernel to accept requests to use it. The kernel and user process synchronize use of the buffers with atomic operations, avoiding the need for system calls under load; the user process may use select()/poll()/kqueue() to manage blocking while waiting for network data if the user process is able to consume data faster than the kernel generates it. Patchs to libpcap are available to allow libpcap applications to transparently take advantage of this support. Detailed information on the new API may be found in bpf(4), including specific atomic operations and memory barriers required to synchronize buffer use safely. These changes modify the base BPF implementation to (roughly) abstrac the current buffer model, allowing the new shared memory model to be added, and add new monitoring statistics for netstat to print. The implementation, with the exception of some monitoring hanges that break the netstat monitoring ABI for BPF, will be MFC'd. Zerocopy bpf buffers are still considered experimental are disabled by default. To experiment with this new facility, adjust the net.bpf.zerocopy_enable sysctl variable to 1. Changes to libpcap will be made available as a patch for the time being, and further refinements to the implementation are expected. Sponsored by: Seccuris Inc. In collaboration with: rwatson Tested by: pwood, gallatin MFC after: 4 months [1] [1] Certain portions will probably not be MFCed, specifically things that can break the monitoring ABI.		2008-03-24 13:49:17 +00:00
bin	Reset the internal state used for the 'getopts' built-in when 'shift' or 'set'	2008-03-22 14:06:01 +00:00
cddl	Remove _SOLARIS_C_SOURCE now that it doesn't do anything in FreeBSD	2007-11-28 22:58:09 +00:00
compat/opensolaris	Add more OpenSolaris compatibilty headers.	2007-11-28 21:40:07 +00:00
contrib	Resolve conflicts.	2008-03-20 02:56:24 +00:00
crypto	Fix the Xlist so it actually works with 'tar -X', and update the upgrade	2008-02-06 23:14:24 +00:00
etc	Be sure to run rc.d/zfs before mountcritremote. This way we can for example	2008-03-19 14:44:55 +00:00
games	Fix typo.	2008-03-03 10:06:52 +00:00
gnu	Re-enable the CVS build.	2008-03-19 15:21:44 +00:00
include	Add POSIX pthread API pthread_getcpuclockid() to get a thread's cpu	2008-03-22 09:59:20 +00:00
kerberos5	While checking over the libraries for 7.0-REL Kris found the following	2007-11-20 04:20:32 +00:00
lib	- Restore kse.h in this directory so other tools don't find it by mistake.	2008-03-23 09:38:11 +00:00
libexec	For un-prototyped static inline functions declared in pthread_md.h on	2007-12-01 14:24:44 +00:00
release	New release notes: KSE removed, cmx(4), uslcom(4), sf(4) update,	2008-03-23 04:12:07 +00:00
rescue	Add an alias for glabel(8).	2008-03-05 23:32:12 +00:00
sbin	Remove comment about "-r" flag from readlabel. "-r" is a no-op.	2008-03-23 03:01:10 +00:00
secure	For users of FreeBSD <= 6.2 we recommend during the x.org 7.x upgrade	2008-03-05 20:58:15 +00:00
share	Introduce support for zero-copy BPF buffering, which reduces the	2008-03-24 13:49:17 +00:00
sys	Introduce support for zero-copy BPF buffering, which reduces the	2008-03-24 13:49:17 +00:00
tools	sync w/ p4: minor cleanups to improve msgs	2008-03-22 16:39:30 +00:00
usr.bin	Fix splitting into words of the .for expression to allow for	2008-03-24 12:33:28 +00:00
usr.sbin	When updating the install list for files which have had local changes	2008-03-23 13:41:54 +00:00
COPYRIGHT	Happy new year 2008!	2007-12-31 22:09:19 +00:00
LOCKS	Once the release goes out, RELENG_7_* will need approval from so@.	2008-01-24 22:07:03 +00:00
MAINTAINERS	OLDCARD is gone, release imp's lock.	2008-01-26 21:58:52 +00:00
Makefile	Add a note pointing to build(7) for more info.	2008-01-30 19:33:18 +00:00
Makefile.inc1	Set AR=gnu-ar and RANLIB=gnu-ranlib on systems where we are forced	2008-03-02 11:10:46 +00:00
ObsoleteFiles.inc	Add an include file from the removed XRPU driver.	2008-03-13 18:17:46 +00:00
README	Simply running ``make world'' will bomb unless you dig up the	2006-06-07 03:33:48 +00:00
UPDATING	- Add an UPDATING entry about the removal of KSE.	2008-03-12 09:48:42 +00:00

README

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.

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