freebsd kernel with SKQ
c28447da4c
the adapter's selections. Many fast periferals were getting upset when the sequencer decided to rearbitrate after the device had already won arbitration. This also forced the creation of a list threaded through the SCBs (since we don't have enough space anywhere else) of commands that are awaiting reselection. This list is run down before any new transactions from the input queue are allowed. The list is appened to whenever we begin a selection (simple case since the selecting device is always at the head) and by the kernel driver whenever a request sense occurs. In the common case, the list is only one element long, but when a reselection wins out over a selection and that reselection generates a request sense, the outstanding selection required for the retreval of the sense code grows the list. On machines with many targets, this might cause the list to grow large, so this solution, which will allow up to the maximum number of I/O requests capible of the card elements in the list, was chosen. The list manipulation is trivial and adds three sequencer instructions of overhead to the selection phase. This fixes the "target busy" errors from micropolis drives and the bursty I/O problem when performing I/O between a Quantum Grand Prix and any other device. I anticipate that this will correct many of the problems that have been reported with this driver. Reviewed by: Wcarchive and David Greenman |
||
---|---|---|
bin | ||
eBones | ||
etc | ||
games | ||
gnu | ||
include | ||
lib | ||
libexec | ||
lkm | ||
release | ||
sbin | ||
secure | ||
share | ||
sys | ||
tools/regression/usr.bin/sed | ||
usr.bin | ||
usr.sbin | ||
COPYRIGHT | ||
CVS-INFO | ||
HW.TROUBLE | ||
Makefile | ||
README | ||
TODO |
----------------------------------------- FreeBSD 2.0 --- ALPHA Release , , ----------------------------------------- /( )` \ \___ / | Welcome to the ALPHA release of FreeBSD 2.0 - the /- _ `-/ ' first public snapshot of our new 4.4BSD Lite based (/\/ \ \ /\ operating system environment. This install proce- / / | ` \ dure is also at the ALPHA stage, and contains only O O ) / | the minimum functionality required by an `-^--'`< ' *EXPERIENCED* person to install the system. (_.) _ ) / It is our hope, of course, that the feedback `.___/` / provided from this snapshot will `-----' / greatly assist us in making the release <----. __ / __ \ of 2.0 much more user friendly. Your <----|====O)))==) \) /==== comments and criticisms are very <----' `--' `.__,' \ valuable to us, so please don't hesitate | | in contacting us! Full details on where and \ / /\ how to provide feedback are given below. ______( (_ / \______/ ,' ,-----' | This install procedure is ALPHA code, and `--{__________) may very possibly *DESTROY* the contents of your ENTIRE DISK! Please do not proceed with this installation unless you've adequately backed up your data first! If any errors occur during this installation, you can see them by toggling over to the alternate screen - type ALT-F2 to switch over, ALT-F1 to switch back to the install screen. The debugging output on the second screen may be very valuable to us in understanding your bug report, so please be sure to take note of it when reporting any failures in the installation! Thanks! Menus and scrolling output windows may be traversed with the arrow and Page Up/Page Down keys. To suspend the installation at any point, hit ESC twice. Hitting TAB will move the focus to different controls. If you've ever dealt with a DOS installation, you'll know how to deal with this. For a more complete description of what's new in this release, please see the release notes. For more documentation on this system, it is recommended that you purchase the 4.4BSD Document Set from O'Reilly Associates and the USENIX Association. ISBN 1-56592-082-1 We have no connection with O'Reilly, we're just satisfied customers! Have fun, and please let us know of any problems you encounter with this release! Comments should be sent to: hackers@FreeBSD.org Bug reports should be sent using the `send-pr' utility, if you were able to get the system installed, otherwise to: bugs@FreeBSD.org And general questions to: questions@FreeBSD.org Please have patience if your questions are not answered right away - this is an especially busy time for us, and our volunteer resources are often strained to the limit (if not somewhat past!). Thanks! The FreeBSD Project