freebsd with flexible iflib nic queues
875b66a05b
Back in 1.1 of kern_sysctl.c the sysctl() routine wired the "old" userland buffer for most sysctls (everything except kern.vnode.*). I think to prevent issues with wiring too much memory it used a 'memlock' to serialize all sysctl(2) invocations, meaning that only one user buffer could be wired at a time. In 5.0 the 'memlock' was converted to an sx lock and renamed to 'sysctl lock'. However, it still only served the purpose of serializing sysctls to avoid wiring too much memory and didn't actually protect the sysctl tree as its name suggested. These changes expand the lock to actually protect the tree. Later on in 5.0, sysctl was changed to not wire buffers for requests by default (sysctl_handle_opaque() will still wire buffers larger than a single page, however). As a result, user buffers are no longer wired as often. However, many sysctl handlers still wire user buffers, so it is still desirable to serialize userland sysctl requests. Kernel sysctl requests are allowed to run in parallel, however. - Expose sysctl_lock()/sysctl_unlock() routines to exclusively lock the sysctl tree for a few places outside of kern_sysctl.c that manipulate the sysctl tree directly including the kernel linker and vfs_register(). - sysctl_register() and sysctl_unregister() require the caller to lock the sysctl lock using sysctl_lock() and sysctl_unlock(). The rest of the public sysctl API manage the locking internally. - Add a locked variant of sysctl_remove_oid() for internal use so that external uses of the API do not need to be aware of locking requirements. - The kernel linker no longer needs Giant when manipulating the sysctl tree. - Add a missing break to the loop in vfs_register() so that we stop looking at the sysctl MIB once we have changed it. MFC after: 1 month |
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| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| games | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| 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. 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