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chunks. This allows runs to be any multiple of the page size. The primary advantage is that large objects are no longer constrained to be 2^n pages, which can dramatically decrease internal fragmentation for large objects. This also allows the sizes for runs that back small objects to be more finely tuned. Free runs are searched for linearly using the chunk page map (with the help of some heuristic optimizations). This changes the allocation policy from "first best fit" to "first fit". A prototype red-black tree implementation for tracking free runs that implemented "first best fit" did not cause a measurable speed or memory usage difference for realistic chunk sizes (though of course it is possible to construct benchmarks that favor one allocation policy over another). Refine the handling of fullness constraints for small runs to be more tunable. Restructure the per chunk page map to contain only two fields per entry, rather than four. Also, increase each entry from 4 to 8 bytes, since it allows for 32-bit integers, without increasing the number of chunk header pages. Relax the maximum chunk size constraint. This is of no practical interest; it is merely fallout from the chunk page map restructuring. Revamp statistics gathering and reporting to be faster, clearer and more informative. Statistics gathering is fast enough now to have little to no impact on application speed, but it still requires approximately two extra pages of memory per arena (per process). This memory overhead may be acceptable for most systems, but we still need to leave statistics gathering disabled by default in RELENG branches. Rename NO_MALLOC_EXTRAS to MALLOC_PRODUCTION in order to make its intent clearer (i.e. it should be defined in RELENG branches).
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