freebsd kernel with SKQ
15a925bf93
that describe a buffer of variable size). The problem is, allocating MDLs off the heap is slow, and it can happen that drivers will allocate lots and lots of lots of MDLs as they run. As a compromise, we now do the following: we pre-allocate a zone for MDLs big enough to describe any buffer with 16 or less pages. If IoAllocateMdl() needs a MDL for a buffer with 16 or less pages, we'll allocate it from the zone. Otherwise, we allocate it from the heap. MDLs allocate from the zone have a flag set in their mdl_flags field. When the MDL is released, IoMdlFree() will uma_zfree() the MDL if it has the MDL_ZONE_ALLOCED flag set, otherwise it will release it to the heap. The assumption is that 16 pages is a "big number" and we will rarely need MDLs larger than that. - Moved the ndis_buffer zone to subr_ntoskrnl.c from kern_ndis.c and named it mdl_zone. - Modified IoAllocateMdl() and IoFreeMdl() to use uma_zalloc() and uma_zfree() if necessary. - Made ndis_mtop() use IoAllocateMdl() instead of calling uma_zalloc() directly. Inspired by: discussion with Giridhar Pemmasani |
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| bin | ||
| contrib | ||
| crypto | ||
| etc | ||
| games | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| COPYRIGHT | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| 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 ``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. 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