freebsd kernel with SKQ
e9271f5376
After discussions with jeff, alc, (various Ironport people), david Xu, and mostly Alfred (who found the problem) it has been demonstrated that this is not needed for our implementations of threads and represents a real (as in we've seen it happen a lot) deadlock danger. Several points: Since forking multiple threads is not allowed, and posix states that any mutexes owned by othre threads wilol be owned in the child by phantom threads, and therads shouldn't ba accessing shared structures without protection, It can be proved that if this leads to the child process accessing inconsistent data, it's a programming error. The mode of thread_single() being used in fork() is the wrong one. It is using SINGLE_NO_EXIT when it should be using SINGLE_BOUNDARY. Even if this we used, System processes have no need to do it as they have no userland to get inconsistent. This commmit first fixes the above bugs to get tehm correct in CVS. then removes them with #ifdef. This is so that history contains the corrected version should it be needed in the future. This code may be needed if we implement the forkall() syscall from Solaris. It may be needed for other non-posix thread libraries at some time in the future, so let the code sit for a short while while I do some work on it anyhow. This removes a reproducible lockup in NFS. It may be argued that maybe doing a fork while holding a vnode lock may not be the best idea in th efirst place but it shouldn't cause a deadlock. The removal has been running under soak test for several days now. This removal should be seriously considered for 7.0 and RELENG_6. Note. There is code in the core-dumping code that may have a similar problem with coredumping threaded processes MFC After: 4 days |
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| bin | ||
| cddl | ||
| compat/opensolaris | ||
| 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