freebsd with flexible iflib nic queues
5e758b9561
application wishes to request high precision time stamps be returned: Alias Existing CLOCK_REALTIME_PRECISE CLOCK_REALTIME CLOCK_MONOTONIC_PRECISE CLOCK_MONOTONIC CLOCK_UPTIME_PRECISE CLOCK_UPTIME Add experimental low-precision clockid_t names corresponding to these clocks, but implemented using cached timestamps in kernel rather than a full time counter query. This offers a minimum update rate of 1/HZ, but in practice will often be more frequent due to the frequency of time stamping in the kernel: New clockid_t name Approximates existing clockid_t CLOCK_REALTIME_FAST CLOCK_REALTIME CLOCK_MONOTONIC_FAST CLOCK_MONOTONIC CLOCK_UPTIME_FAST CLOCK_UPTIME Add one additional new clockid_t, CLOCK_SECOND, which returns the current second without performing a full time counter query or cache lookup overhead to make sure the cached timestamp is stable. This is intended to support very low granularity consumers, such as time(3). The names, visibility, and implementation of the above are subject to change, and will not be MFC'd any time soon. The goal is to expose lower quality time measurement to applications willing to sacrifice accuracy in performance critical paths, such as when taking time stamps for the purpose of rescheduling select() and poll() timeouts. Future changes might include retrofitting the time counter infrastructure to allow the "fast" time query mechanisms to use a different time counter, rather than a cached time counter (i.e., TSC). NOTE: With different underlying time mechanisms exposed, using different time query mechanisms in the same application may result in relative non-monoticity or the appearance of clock stalling for a single clockid_t, as a cached time stamp queried after a precision time stamp lookup may be "before" the time returned by the earlier live time counter query. |
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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 | ||
| 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 ``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