freebsd kernel with SKQ
25da94eb3e
o Introduce a notion of "not ready" mbufs in socket buffers. These mbufs are now being populated by some I/O in background and are referenced outside. This forces following implications: - An mbuf which is "not ready" can't be taken out of the buffer. - An mbuf that is behind a "not ready" in the queue neither. - If sockbet buffer is flushed, then "not ready" mbufs shouln't be freed. o In struct sockbuf the sb_cc field is split into sb_ccc and sb_acc. The sb_ccc stands for ""claimed character count", or "committed character count". And the sb_acc is "available character count". Consumers of socket buffer API shouldn't already access them directly, but use sbused() and sbavail() respectively. o Not ready mbufs are marked with M_NOTREADY, and ready but blocked ones with M_BLOCKED. o New field sb_fnrdy points to the first not ready mbuf, to avoid linear search. o New function sbready() is provided to activate certain amount of mbufs in a socket buffer. A special note on SCTP: SCTP has its own sockbufs. Unfortunately, FreeBSD stack doesn't yet allow protocol specific sockbufs. Thus, SCTP does some hacks to make itself compatible with FreeBSD: it manages sockbufs on its own, but keeps sb_cc updated to inform the stack of amount of data in them. The new notion of "not ready" data isn't supported by SCTP. Instead, only a mechanical substitute is done: s/sb_cc/sb_ccc/. A proper solution would be to take away struct sockbuf from struct socket and allow protocols to implement their own socket buffers, like SCTP already does. This was discussed with rrs@. Sponsored by: Netflix Sponsored by: Nginx, Inc. |
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| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| games | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| ObsoleteFiles.inc | ||
| README | ||
| UPDATING | ||
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