1) check va before clearing the page clean flag. Not doing so was
causing the vnode pager error 5 messages when paging from
NFS. (pmap.c)
2) put back interrupt protection in idle_loop. Bruce didn't think
it was necessary, John insists that it is (and I agree). (swtch.s)
3) various improvements to the clustering code (vm_machdep.c). It's
now enabled/used by default.
4) bad disk blocks are now handled properly when doing clustered IOs.
(wd.c, vm_machdep.c)
5) bogus bad block handling fixed in wd.c.
6) algorithm improvements to the pageout/pagescan daemons. It's amazing
how well 4MB machines work now.
>From: Adam David <adam@veda.is>
Subject: SCSI timeout in sdopen()
Date: Sun, 6 Feb 1994 21:40:48 GMT
Index: sys FreeBSD-current
Reference: FreeBSD-current/sys/9
Description:
sdopen() times out on slow SCSI devices. This code was moved into
a different file, which might explain why it got missed again.
Repeat-By:
using slow SCSI disks
cd.c:
Initialize channel info in CDIOCSETVOL ioctl.
Correct CDIOCSTOP and CDIOCEJCET ioctls to use scsi_stop_unit
instead of scsi_start_unit.
Add CDIOCALLOW and CDIOCPREVENT ioctls.
ch.h:
Return EBUSY instead of ENXIO if the device is already in use.
scsi_base.c:
Add scsi_stop_unit routine.
sd.c:
Add mising indirection through sc_link to sd_get_parms routine
when checking for media loaded.
st.c:
Return EBUSY instead of ENXIO if the device is already in use.
Clear the SDEV_WAITING flag in ststart if we do the wakeup call.
a binary link-kit. Make all non-optional options (pagers, procfs) standard,
and update LINT to reflect new symtab requirements.
NB: -Wtraditional will henceforth be forgotten. This editing pass was
primarily intended to detect any constructions where the old code might
have been relying on traditional C semantics or syntax. These were all
fixed, and the result of fixing some of them means that -Wall is now a
realistic possibility within a few weeks.
Here is the fix for the 'hanging' bug.
This bug happenned whenever two operations were already underway on the
disk and a third (non-IO) command was requested..
in this case the process submitting the NON-IO command was requested to wait,
and a flag set so that on completion of the IO commands, the Non-io command
was given priority over any pending IO commands. (the queue is not
allowed to drain while there are pending "special" ops).
The flag that indicated this was not being reset, so further IO commands
were prohibited from that moment on.
