freebsd kernel with SKQ
1fd90b0565
Previously rl(4) continuously checked whether there are RX events or TX completions in forever loop. This caused TX starvation under high RX load as well as consuming too much CPU cycles in the interrupt handler. If interrupt was shared with other devices which may be always true due to USB devices in these days, rl(4) also tried to process the interrupt. This means polling(4) was the only way to mitigate the these issues. To address these issues, rl(4) now disables interrupts when it knows the interrupt is ours and limit the number of iteration of the loop to 16. The interrupt would be enabled again before exiting interrupt handler if the driver is still running. Because RX buffer is 64KB in size, the number of iterations in the loop has nothing to do with number of RX packets being processed. This change ensures sending TX frames under high RX load. RX handler drops a driver lock to pass received frames to upper stack such that there is a window that user can down the interface. So rl(4) now checks whether driver is still running before serving RX or TX completion in the loop. While I'm here, exit interrupt handler when driver initialized controller. With this change, now rl(4) can send frames under high RX load even though the TX performance is still not good(rl(4) controllers can't queue more than 4 frames at a time so low TX performance was one of design issue of rl(4) controllers). It's much better than previous TX starvation and you should not notice RX performance drop with this change. Controller still shows poor performance under high network load but for many cases it's now usable without resorting to polling(4). MFC after: 2 weeks |
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| 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. 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