Fixed remaining known bugs in the buffer IO and VM system.
vfs_bio.c:
Fixed some race conditions and locking bugs. Improved performance
by removing some (now) unnecessary code and fixing some broken
logic.
Fixed process accounting of # of FS outputs.
Properly handle NFS interrupts (B_EINTR).
(various)
Replaced calls to clrbuf() with calls to an optimized routine
call vfs_bio_clrbuf().
(various FS sync)
Sync out modified vnode_pager backed pages.
ffs_vnops.c:
Do two passes: Sync out file data first, then indirect blocks.
vm_fault.c:
Fixed deadly embrace caused by acquiring locks in the wrong order.
vnode_pager.c:
Changed to use buffer I/O system for writing out modified pages. This
should fix the problem with the modification date previous not getting
updated. Also dramatically simplifies the code. Note that this is
going to change in the future and be implemented via VOP_PUTPAGES().
vm_object.c:
Fixed a pile of bugs related to cleaning (vnode) objects. The performance
of vm_object_page_clean() is terrible when dealing with huge objects,
but this will change when we implement a binary tree to keep the object
pages sorted.
vm_pageout.c:
Fixed broken clustering of pageouts. Fixed race conditions and other
lockup style bugs in the scanning of pages. Improved performance.
drivers to protect DDB from being invoked while the console is in
process-controlled (i.e., graphics) mode.
Implement the logic to use this hook from within pcvt. (I'm sure
Søren will do the syscons part RSN).
I've still got one occasion where the system stalled, but my attempts
to trigger the situation artificially resulted int the expected
behaviour. It's hard to track bugs without the console and DDB
available. :-/
Added a new type to uiomove - "UIO_NOCOPY" which causes it to update
pointers and counts, but doesn't do any data copying. This is needed
for upcoming changes to the way that the vnode pager does its page
outs.
Added a new hash init function call "phashinit" that allocates and
initializes a prime number sized hash table.
vfs_cache.c:
Changed hashing algorithm to use the remainder of dividing by a prime
number to improve the distribution characteristcs. Uses new phashinit
function in kern_subr.c.
#179). The fix implements a ttyhalfclose() (sort of), resetting the
session and pgrp pointers when the physical device is about to be
closed.
Suggested by: bde
1) Preserve old buffer contents when input buffer overflows.
Old code clear buffer and rewrite it again, if !MAXBEL
(for MAXBEL it does right thing :-).
F.e. if you type too long string, last chars passed,
not first ones as expected.
Moreover, it flush output queue too in this case without any needs.
2) Don't do IXOFF, if IGNCR and c==\r, ignore completely.
3) If PARMRK is active and !ISTRIP and char == 0377
put yet one 0377 to distinguish it from parity mark sequence.
POSIX standard (thanx Bruce).
Reviewed by:
Submitted by:
Obtained from:
CVS:
merged cache changes, and figure it out based on the B_VMIO buffer flag.
Fixes a problem where delayed write VMIO buffers would sometimes get
recopied into kernel-alloced memory.
Submitted by: John Dyson
- ignore the partition table if it is identical with the bogus one in
/usr/src/sys/i386/boot/biosboot/start.S. Honoring the bogus size
field was fatal. The error is detected but other compatibilty
cruft weakens the error handling too much for this case.
- weaken the partition entry checking to allow the following treatments
of C/H/S addresses when C should be >= 1024:
(1) allow C = 1023, H = max, S = max.
(2) allow C to be correct modulo 1024.
Other compatibilty cruft weakens the error handling to allow all
C/H/S addresses, but there too many errors were reported.
Improve error messages:
- print C/H/S addresses if relevant.
- distinguish primary partition table from extended partition tables.
- don't use diskerr() except for i/o errors.
to the user address space unless pcb_onfault is set. The code is currently
commented out because iBCS2 and process debugging parts of the kernel
need to be changed/fixed first.
It was previously after the VOP_RENAME and the reference and lock on
the vnode had already been lost, allowing interesting internel
inconsistencies. This is one of the two reasons why freefall was crashing
every hour or two (the other being nullfs bugs).
Don't call vnode_pager_uncache in revoke(). revoke() is only allowed on
VCHR and VBLK vnodes.
now returns NULL and sets a global 'mb_map_full' when the map is full.
m_clalloc() has further been taught to expect this and do the right thing.
This should fix the "mb_map full" panics that several people have reported.
1. We always keep one 16th of the vnodes on the freelist, so that the
namecache doesn't get trashed. It used to be that it wasn't a problem, but
the only vnodes getting released these days are directories and things which
Clean up and improve the namecache.
1. We always keep one 16th of the vnodes on the freelist, so that the
namecache doesn't get trashed. It used to be that it wasn't a problem, but
the only vnodes getting released these days are directories and things which
gets forced out of the VM/cache. The latter is not numerous enough to keep
the pool of vnodes needed for the namecache sufficiently big.
2. Purge invalid entries in the namecache as soon as we notice them. This
avoids a stale entry pushing out a valid entry on the LRU list.
3. Speed up the lookup in the namecache by avoid a special case branch.
4. Make the cache purge routines do the thing they're supposed to, and in
a decently efficient manner.
5. Make the size of the namecache follow the number of vnodes, so that we
can always point to all the vnodes we have in core.
6. Readability has gone way up.
7. Added a "options NCH_STATISTICS" feature that will gather more
detailed statistics on the performance of the namecache.
Reviewed by: davidg
(cvs is dumping core on me :-( )
1. We always keep one 16th of the vnodes on the freelist, so that the
namecache doesn't get trashed. It used to be that it wasn't a problem, but
the only vnodes getting released these days are directories and things which
gets forced out of the VM/cache. The latter is not numerous enough to keep
the pool of vnodes needed for the namecache sufficiently big.
2. Purge invalid entries in the namecache as soon as we notice them. This
avoids a stale entry pushing out a valid entry on the LRU list.
3. Speed up the lookup in the namecache by avoid a special case branch.
4. Make the cache purge routines do the thing they're supposed to, and in
a decently efficient manner.
5. Make the size of the namecache follow the number of vnodes, so that we
can always point to all the vnodes we have in core.
6. Readability has gone way up.
7. Added a "options NCH_STATISTICS" feature that will gather more
detailed statistics on the performance of the namecache.
Reviewed by: davidg
Don't print debugging messages by default.
Initialize the compatibility slice here and not in the machine-dependent
code.
Fix initialization of the label for the whole disk slice.
Make it clear that write protection of labels doesn't apply when there is
no label.
New functions create - vm_object_pip_wakeup and pagedaemon_wakeup that
are used to reduce the actual number of wakeups.
New function vm_page_protect which is used in conjuction with some new
page flags to reduce the number of calls to pmap_page_protect.
Minor changes to reduce unnecessary spl nesting.
Rewrote vm_page_alloc() to improve readability.
Various other mostly cosmetic changes.
(a) bring back ttselect, now that we have xxxdevtotty() it isn't dangerous.
(b) remove all of the wrappers that have been replaced by ttselect
(c) fix formatting in syscons.c and definition in syscons.h
(d) add cxdevtotty
NOT DONE:
(e) make pcvt work... it was already broken...when someone fixes pcvt to
link properly, just rename get_pccons to xxxdevtotty and we're done
may not properly initialize this field in all cases, and this would
result in very anti-social behavior (overwriting on some other random
device/location).
Submitted by: John Dyson
(b) add a function callback vector to tty drivers that will return a pointer
to a valid tty structure based upon a dev_t
(c) make syscons structures the same size whether or not APM is enabled so
utilities don't crash if NAPM changes (and make the damn kernel compile!)
(d) rewrite /dev/snp ioctl interface so that it is device driver and i386
independant
Fix the sign of the adjustment after writing a label.
Writing of labels should work now.
Merge adjust_label() into fixlabel(). Detect more errors and don't
write if there is an error. Adjust sectors/unit and total sectors
to the numbers on the slice.
Add a function dsname() to print slice device names consistently, and
use it.
Various more tweaks from John Dyson to improve read ahead calculations.
vfs_subr.c:
Only wakeup if numoutput is 0 in vwakeup().
Submitted by: John Dyson
metadata aren't thrashed by regular file I/O.
Added mechanism to limit the amount of outstanding I/O on a given vnode.
Pagedaemon wakeup policy changed to skew priority a little in favor of
file caching.
Slight code reorganization to improve clarity.
Added a few more comments.
Submitted by: John Dyson
the same as when initializing the in-core copies. Adjust checksums in
labels after adjusting labels. This finishes fudging the on-disk label to
make it coherent with the in-core label.
Handle EIO during initialization better.
Initialize the compatibility slice to the whole disk If there are no real
slices.
Don't warn about adjusting offsets in the label to make the 'c' partition
start at 0. The 'c' offset is now always absolute on-disk and 0 in-core
so an adjustment is usually required.
Don't confuse LABEL_PART with RAW_PART so much.
Check for partitions being within slices differently.
via sysctl(8). The initial value of maxprocperuid is maxproc-1,
that of maxfilesperproc is maxfiles (untill maxfile will disappear)
Now it is at least possible to prohibit one user opening maxfiles
-Guido
Submitted by:
Obtained from:
requires complications to adjust the offsets to relative when a block
containing the label is read and back to absolute when such a block is
written. The adjustment is not made on the whole disk slice.
Don't allow setting the offset of partition C to nonzero in in-core labels.
This will cause some (nonstandard) disktab entries to fail. They will
need to be changed to have relative offsets (and no partitions outside
of the slice).
Don't write protect the (nonexistent) label on the whole disk slice.
Writing labels and bootstraps should work right now (except if there is
no DOSpartition table).
Slice 0 is now for the first BSD slice. The first BSD slice is
the first DOSpartition with id 0xa5 or the whole disk if their
are no DOSpartitions (except the latter is not yet implemented).
Existing partitions on it work the same as in 2.0 except the
'd' partition is no longer special and partitions are relative
to the skice.
Slice 1 is now for the whole disk and gets a read-only label
describing the disk. Previously, slice 0 was for the whole disk
and there was no label on it.
Slices 2-31 are for DOSpartitions. Slice 0 is an alias for one
of these if there is a BSD slice. Previously, slices 1-31 were
for DOSpartitions.
diskslice_machdep.c:
Expand whole disk slice to include all DOSpartitions. More work
is required for >1024 cylinders and to rewrite the label iff the
driver is unsure about the geometry.
subr_diskslice.c:
New function dsisopen() to help handle media changes.
mapping from numbers to names is messy for backwards compatibility.
E.g., for driver "sd", unit "0":
slice 0: omit the slice number for compatibility; names are sd0[a-h].
slice 1: omit the partition letter 'c' because the whole disk device
shouldn't have anything to do with partitions; sd0 is the
only name.
slices 2-31: subtract 1 from slice number to compensate for the
compatibility slice 0; names are sd0s[1-30][a-h].
