FreeBSD src
1d3c0fa7b2
preserve the ABI and API for applications. It was removed in the port to amd64, but was remained as garbage giving a micro-pessimization and spurious single-step traps on i386. pcb_psl was intended to be used just to do a context switch of PSL_I, but this context switch was null in most or all versions, and mis-switching of PSL_T was done instead. Some history: - in 386BSD-0.0, cpu_switch() ran at splhigh() and splhigh() did too much interrupt disabling, so interrupts were hard-disabled across cpu_switch() and too many other places - in 386BSD-0.0-patchkit through FreeBSD-4 and FreeBSD-5 before SMPng, splhigh() did soft interrupt masking, and cpu_switch() was excessively cautious and did a cli at the start and a sti at the end to hard-disable interrupts across the switch - SMPng replaced the spl's and cli's by spinlocks (just sched_lock?), so interrupts were hard-disabled across cpu_switch() and too many other places again - initial attempts to fix this intended to restore some soft interrupt disabling, but to support variations in this cpu_switch() used pushfl/popfl into pcb_psl to avoid hard-coding the assumption that the initial and final states have PSL_I enabled. But the version with soft interrupt disabling wasn't used for long, or was never committed, (except I always used my different version of it for UP) so the pushfl/popl and pcb_psl to hold them have been doing less than nothing for about 14 years. |
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| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| targets | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.libcompat | ||
| 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. See build(7) and 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. See build(7), config(8), and http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information. 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 kernel configuration files reside in the sys/<arch>/conf sub-directory. GENERIC is the default configuration used in release builds. NOTES contains entries and documentation for all possible devices, not just those commonly used. Source Roadmap: --------------- bin System/user commands. cddl Various commands and libraries under the Common Development and Distribution License. contrib Packages contributed by 3rd parties. crypto Cryptography stuff (see crypto/README). etc Template files for /etc. 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. tests Regression tests which can be run by Kyua. See tests/README for additional information. 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