FreeBSD src
875b8844be
writing event timer drivers, for choosing best possible drivers by machine independent code and for operating them to supply kernel with hardclock(), statclock() and profclock() events in unified fashion on various hardware. Infrastructure provides support for both per-CPU (independent for every CPU core) and global timers in periodic and one-shot modes. MI management code at this moment uses only periodic mode, but one-shot mode use planned for later, as part of tickless kernel project. For this moment infrastructure used on i386 and amd64 architectures. Other archs are welcome to follow, while their current operation should not be affected. This patch updates existing drivers (i8254, RTC and LAPIC) for the new order, and adds event timers support into the HPET driver. These drivers have different capabilities: LAPIC - per-CPU timer, supports periodic and one-shot operation, may freeze in C3 state, calibrated on first use, so may be not exactly precise. HPET - depending on hardware can work as per-CPU or global, supports periodic and one-shot operation, usually provides several event timers. i8254 - global, limited to periodic mode, because same hardware used also as time counter. RTC - global, supports only periodic mode, set of frequencies in Hz limited by powers of 2. Depending on hardware capabilities, drivers preferred in following orders, either LAPIC, HPETs, i8254, RTC or HPETs, LAPIC, i8254, RTC. User may explicitly specify wanted timers via loader tunables or sysctls: kern.eventtimer.timer1 and kern.eventtimer.timer2. If requested driver is unavailable or unoperational, system will try to replace it. If no more timers available or "NONE" specified for second, system will operate using only one timer, multiplying it's frequency by few times and uing respective dividers to honor hz, stathz and profhz values, set during initial setup. |
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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