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Peter Wemm a2a1c95c10 The biggie: Get rid of the UPAGES from the top of the per-process address
space. (!)

Have each process use the kernel stack and pcb in the kvm space.  Since
the stacks are at a different address, we cannot copy the stack at fork()
and allow the child to return up through the function call tree to return
to user mode - create a new execution context and have the new process
begin executing from cpu_switch() and go to user mode directly.
In theory this should speed up fork a bit.

Context switch the tss_esp0 pointer in the common tss.  This is a lot
simpler since than swithching the gdt[GPROC0_SEL].sd.sd_base pointer
to each process's tss since the esp0 pointer is a 32 bit pointer, and the
sd_base setting is split into three different bit sections at non-aligned
boundaries and requires a lot of twiddling to reset.

The 8K of memory at the top of the process space is now empty, and unmapped
(and unmappable, it's higher than VM_MAXUSER_ADDRESS).

Simplity the pmap code to manage process contexts, we no longer have to
double map the UPAGES, this simplifies and should measuably speed up fork().

The following parts came from John Dyson:

Set PG_G on the UPAGES that are now in kernel context, and invalidate
them when swapping them out.

Move the upages object (upobj) from the vmspace to the proc structure.

Now that the UPAGES (pcb and kernel stack) are out of user space, make
rfork(..RFMEM..) do what was intended by sharing the vmspace
entirely via reference counting rather than simply inheriting the mappings.
1997-04-07 07:16:06 +00:00
bin Fix several problems with mkdir: 1997-04-01 23:46:22 +00:00
contrib Disallow "-p" when linking, with a diagnostic that recommends using 1997-04-05 16:19:08 +00:00
eBones Use srandomdev() now 1997-03-24 14:52:51 +00:00
etc Make the default VERASE key the <-- key and remove root's 1997-04-03 21:42:42 +00:00
games Use srandomdev() now 1997-03-30 23:33:29 +00:00
gnu Bmake Makefile for building info files for GNU cpio. 1997-04-03 11:20:39 +00:00
include Declare issetugid() 1997-04-05 13:03:15 +00:00
lib Speedup in case locale not used 1997-04-04 20:10:53 +00:00
libexec Use MAXHOSTNAMELEN, as opposed to an arbitrary number, and ensure 1997-04-01 20:39:59 +00:00
lkm Make MOD_* macros almost consistent: 1997-04-06 11:14:13 +00:00
release YAMF22 1997-04-05 07:08:14 +00:00
sbin Allow "modern" syntax: 1997-04-02 17:05:30 +00:00
secure Revert $FreeBSD$ to $Id$ 1997-02-22 14:40:44 +00:00
share New translation which corresponds to the 1.11 -> 1.12 change of 1997-04-07 04:56:51 +00:00
sys The biggie: Get rid of the UPAGES from the top of the per-process address 1997-04-07 07:16:06 +00:00
tools Add ac which check if the FreeBSD handbook is in sync with the committers list 1997-03-28 14:40:39 +00:00
usr.bin Support for -c, byte count. 1997-04-06 00:54:27 +00:00
usr.sbin YAMF22 1997-04-05 07:08:14 +00:00
COPYRIGHT This is the official 4.4 Lite copyright. 1994-09-11 07:53:28 +00:00
Makefile Back out csu fix, because it was just fixed differently 1997-04-02 17:10:16 +00:00
README Revert $FreeBSD$ to $Id$ 1997-02-23 09:21:14 +00:00

This is the top level of the FreeBSD source directory.  This file
was last revised on: $Id$

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.  Please see the top of the Makefile for more information on
the standard build targets and compile-time flags.

Building a kernel with config(8) is a somewhat more involved process,
documentation for which can be found at:
   http://www.freebsd.org/handbook/kernelconfig.html
And in the config(8) man page.

The sample kernel configuration files reside in the sys/i386/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 LINT contains entries for all possible devices, not
just those commonly used, and is meant more as a general reference
than an actual kernel configuration file (a kernel built from it
wouldn't even run).


Source Roadmap:
---------------
bin		System/User commands.

contrib		Packages contributed by 3rd parties.

eBones		Kerberos package - NOT FOR EXPORT!

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.

lib		System libraries.

libexec		System daemons.

lkm		Loadable Kernel Modules.

release		Release building Makefile & associated tools.

sbin		System commands.

secure		DES and DES-related utilities - NOT FOR EXPORT!

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/handbook/synching.html