a971139680
multiprocessors. Specifically, the error is conditioning the call to pmap_invalidate_page() on whether the pmap is active on the current CPU. This call must be unconditional. Regardless of whether the pmap is active on the CPU performing _pmap_unwire_pte_hold(), it could be active on another CPU. For example, a call to pmap_remove_all() by the page daemon could result in a call to _pmap_unwire_pte_hold() with the pmap inactive on the current CPU and active on another CPU. In such circumstances, failing to call pmap_invalidate_page() results in a stale TLB entry on the other CPU that still maps the now deallocated page table page. What happens next is typically a mysterious panic in pmap_enter() by the other CPU, either "pmap_enter: attempted pmap_enter on 4MB page" or "pmap_enter: pte vanished, va: 0x%lx". Both occur because the former page table page has been recycled and allocated to a new purpose. Consequently, it no longer contains zeroes. See also Peter's i386/i386/pmap.c revision 1.448 and the related e-mail thread last year. Many thanks to the engineers at Sandvine for providing clear and concise information until all of the pieces of the puzzle fell into place and for testing an earlier patch. MT5 Candidate
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