FreeBSD src
4d05e7b184
which takes an physical address instead of an virtual one, for loading TTEs of the kernel TSB so we no longer need to lock the kernel TSB into the dTLB, which only has a very limited number of lockable dTLB slots. The net result is that we now basically can handle a kernel TSB of any size and no longer need to limit the kernel address space based on the number of dTLB slots available for locked entries. Consequently, other parts of the trap handlers now also only access the the kernel TSB via its physical address in order to avoid nested traps, as does the PMAP bootstrap code as we haven't taken over the trap table at that point, yet. Apart from that the kernel TSB now is accessed via a direct mapping when we are otherwise taking advantage of ASI_ATOMIC_QUAD_LDD_PHYS so no further code changes are needed. Most of this is implemented by extending the patching of the TSB addresses and mask as well as the ASIs used to load it into the trap table so the runtime overhead of this change is rather low. Currently the use of ASI_ATOMIC_QUAD_LDD_PHYS is not yet enabled on SPARC64 CPUs due to lack of testing and due to the fact it might require minor adjustments there. Theoretically it should be possible to use the same approach also for the user TSB, which already is not locked into the dTLB, avoiding nested traps. However, for reasons I don't understand yet OpenSolaris only does that with SPARC64 CPUs. On the other hand I think that also addressing the user TSB physically and thus avoiding nested traps would get us closer to sharing this code with sun4v, which only supports trap level 0 and 1, so eventually we could have a single kernel which runs on both sun4u and sun4v (as does Linux and OpenBSD). Developed at and committed from: 27C3 |
||
|---|---|---|
| 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 | ||
| Makefile.mips | ||
| 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. 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. 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