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data structure called kse_upcall to manage UPCALL. All KSE binding and loaning code are gone. A thread owns an upcall can collect all completed syscall contexts in its ksegrp, turn itself into UPCALL mode, and takes those contexts back to userland. Any thread without upcall structure has to export their contexts and exit at user boundary. Any thread running in user mode owns an upcall structure, when it enters kernel, if the kse mailbox's current thread pointer is not NULL, then when the thread is blocked in kernel, a new UPCALL thread is created and the upcall structure is transfered to the new UPCALL thread. if the kse mailbox's current thread pointer is NULL, then when a thread is blocked in kernel, no UPCALL thread will be created. Each upcall always has an owner thread. Userland can remove an upcall by calling kse_exit, when all upcalls in ksegrp are removed, the group is atomatically shutdown. An upcall owner thread also exits when process is in exiting state. when an owner thread exits, the upcall it owns is also removed. KSE is a pure scheduler entity. it represents a virtual cpu. when a thread is running, it always has a KSE associated with it. scheduler is free to assign a KSE to thread according thread priority, if thread priority is changed, KSE can be moved from one thread to another. When a ksegrp is created, there is always N KSEs created in the group. the N is the number of physical cpu in the current system. This makes it is possible that even an userland UTS is single CPU safe, threads in kernel still can execute on different cpu in parallel. Userland calls kse_create to add more upcall structures into ksegrp to increase concurrent in userland itself, kernel is not restricted by number of upcalls userland provides. The code hasn't been tested under SMP by author due to lack of hardware. Reviewed by: julian
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. kerberosIV KerberosIV (eBones) 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