Commit Graph

265 Commits

Author SHA1 Message Date
Joerg Wunsch
8eea4d3c76 Add a DDB command `show buffer', to display a struct buf. It's impossible
to display everything, so i've chosen a small subset.  Add more to this as
you think seems useful.
1997-05-10 09:09:42 +00:00
John Dyson
95395ca1c1 Improve the buffer cache memory policy by moving pages over to the
cache queue more often.  The pageout daemon had to be waken up
more often than necessary since pages were not put on the
cache queue, when they should have been.
Submitted by:	David Greenman <dg@freebsd.org>
1997-04-13 03:33:25 +00:00
Bruce Evans
3f39dbc52d Removed potentially harmful garbage <vm/lock.h> and fixed bogus
use of it.  It was actually harmless because the use was null due
to fortuitous include orders and identical (wrong) idempotency
macros.
1997-04-01 08:39:07 +00:00
Peter Wemm
6875d25465 Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.
1997-02-22 09:48:43 +00:00
Bruce Evans
16a02c1105 Removed redundant spl0()'s from kernel processes. They were work-arounds
for a bug in fork().
1997-01-15 19:05:08 +00:00
Jordan K. Hubbard
1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00
John Dyson
3596818baa Clean-up of the new buffer kva allocation code. Also, there was an
error in the !BOUNCE_BUFFERS case.
1996-12-05 04:28:52 +00:00
John Dyson
621d520e2f Fix a problem with the new buffer_map management code. Additionally,
decrease the size of buffer_map to approx 2/3 of what it used to be
(buffer_map can be smaller now.)  The original commit of these changes
increased the size of buffer_map to the point where the system would
not boot on large systems -- now large systems with large caches will
have even less problems than before.
1996-12-01 15:46:40 +00:00
John Dyson
09e0c6ccdd Implement a new totally dynamic (up to MAXPHYS) buffer kva allocation
scheme.  Additionally, add the capability for checking for unexpected
kernel page faults.  The maximum amount of kva space for buffers hasn't
been decreased from where it is, but it will now be possible to do so.

This scheme manages the kva space similar to the buffers themselves.  If
there isn't enough kva space because of usage or fragementation, buffers
will be reclaimed until a buffer allocation is successful.  This scheme
should be very resistant to fragmentation problems until/if the LFS code
is fixed and uses the bogus buffer locking scheme -- but a 'fixed' LFS
is not likely to use such a scheme.

Now there should be NO problem allocating buffers up to MAXPHYS.
1996-11-30 22:41:49 +00:00
John Dyson
71a5742716 Potentially fix a problem, whereby MSDOSFS can request buffers
larger than the vfs layer can provide.  We now automatically support
32K clusters if MSDOSFS is installed, and panic if a filesystem tries
to allocate a buffer larger than MAXBSIZE.

This commit is a result of some "prodding" by BDE.
1996-11-28 04:26:04 +00:00
John Dyson
9970cd3721 Improve the caching of small files like directories, while not
substantially increasing buffer space.  Specifically, we double
the number of buffers, but allocate only half the amount of memory
per buffer.  Note that VDIR files aren't cached unless instantiated
in a buffer.  This will significantly improve caching.
1996-11-17 02:11:01 +00:00
John Dyson
402bcb9621 Fix a problem that could cause msync (or many other things) to deadlock.
The heuristic for managment of memory backing the buffer cache was
nice, but didn't work due to some architectural problems.  Simplify
and improve the algorithm.
1996-10-17 03:04:43 +00:00
John Dyson
ffe2522e29 Fix 4 problems:
Major: When blocking occurs in allocbuf() for VMIO files,
	       excess wire counts could accumulate.
	Major: Pages are incorrectly accumulated into the physical
	       buffer for clustered reads.  This happens when bogus
	       page is needed.
	Minor: When reclaiming buffers, the async flag on the buffer
	       needs to be zero, or the reclaim is not optimal.
	Minor: The age flag should be cleared, if a buffer is wanted.
1996-10-06 07:50:05 +00:00
John Dyson
08c2c9ddf5 Fix an spl window, a page manipulation at interrupt time that was
incorrect, and correct the support for B_ORDERED.  The spl window
fix was from Peter Wemm, and his questions led me to find the problem with
the interrupt time page manipulation.
1996-09-20 02:26:35 +00:00
John Dyson
f9da2540d2 Add needed spl protection, and some minor cleanups in vfs_vmio_release.
Submitted by:	Peter Wemm <peter@spinner.dialix.com> and me.
1996-09-18 15:57:41 +00:00
John Dyson
8fdfa820e4 Clean up some more problems with freeing busy or wired pages. The
vfs_bio code was not waiting properly for page state until manipulating
it.
1996-09-14 04:40:33 +00:00
John Dyson
9fc1279b79 A modification that allows the driver strategy to modify the
B_ASYNC flag broke things pretty bad (freeing buffer already on
queue or other wierd buffer queue errors.)  The broken code is
left in commented out, but this makes the problem go away for
now.
1996-09-13 03:15:45 +00:00
John Dyson
5070c7f8c5 Addition of page coloring support. Various levels of coloring are afforded.
The default level works with minimal overhead, but one can also enable
full, efficient use of a 512K cache.  (Parameters can be generated
to support arbitrary cache sizes also.)
1996-09-08 20:44:49 +00:00
Justin T. Gibbs
0b64164fca Add bowrite.
Bowrite guarantees that buffers queued after a call to bowrite will
be written after the specified buffer (on a particular device).
Bowrite does this either by taking advantage of hardware ordering support
(e.g. tagged queueing on SCSI devices) or resorting to a synchronous write.
1996-09-06 05:37:53 +00:00
John Dyson
6476c0d204 Even though this looks like it, this is not a complex code change.
The interface into the "VMIO" system has changed to be more consistant
and robust.  Essentially, it is now no longer necessary to call vn_open
to get merged VM/Buffer cache operation, and exceptional conditions
such as merged operation of VBLK devices is simpler and more correct.

This code corrects a potentially large set of problems including the
problems with ktrace output and loaded systems, file create/deletes,
etc.

Most of the changes to NFS are cosmetic and name changes, eliminating
a layer of subroutine calls.  The direct calls to vput/vrele have
been re-instituted for better cross platform compatibility.

Reviewed by: davidg
1996-08-21 21:56:23 +00:00
Poul-Henning Kamp
d1c4c866f0 Add separate kmalloc classes for BIO buffers and Ktrace info. 1996-08-04 20:13:08 +00:00
David Greenman
7c818168d5 Fixed a major bug that caused various pmap related panics, hangs, and reboots.
The i386 pmap module uses a special area of kernel virtual memory for mapping
of page tables pages when it needs to modify another process's virtual
address space. It's called the 'alternate page table map'. There is only one
of them and it's expected that only one process will be using it at once and
that the operation is atomic.
When the merged VM/buffer cache was implemented over a year ago, it became
necessary to rundown VM pages at I/O completion. The unfortunate and
unforeseen side effect of this is that pmap functions are now called at bio
interrupt time. If there happend to be a process using the alternate page
table map when this I/O completion occurred, it was possible for a different
process's address space to be switched into the alternate page table map -
leaving the current pmap process with the wrong address space mapped when
the interrupt completed. This resulted in BAD things happening like pages
being mapped or removed from the wrong address space, etc.. Since a very
common case of a process modifying another process's address space is during
fork when the kernel stack is inserted, one of the most common manifestations
of this bug was the kernel stack not being mapped properly, resulting in a
silent hang or reboot. This made it VERY difficult to troubleshoot this bug
(I've been trying to figure out the cause of this for >6 months). Fortunately,
the set of conditions that must be true before this problem occurs is
sufficiently rare enough that most people never saw the bug occur. As I/O
rates increase, however, so does the frequency of the crashes. This problem
used to kill wcarchive about every 10 days, but in more recent times when
the traffic exceeded >100GB/day, the machine could barely manage 6 hours of
uptime.
The fix is to make certain that no process has the pages mapped that are
involved in the I/O, before the I/O is started. The pages are made busy, so
no process will be able to map them, either, until the I/O has finished.
This side-steps the issue by still allowing the pmap functions to be called
at interrupt time, but also assuring that the alternate page table map won't
be switched.
Unfortunately, this appears to not be the only cause of this problem. :-(

Reviewed by:	dyson
1996-06-30 05:17:08 +00:00
Satoshi Asami
ad63a118b2 The Great PC98 Merge.
All new code is "#ifdef PC98"ed so this should make no difference to
PC/AT (and its clones) users.

Ok'd by:	core
Submitted by:	FreeBSD(98) development team
1996-06-14 11:02:28 +00:00
John Dyson
268e9c5397 Keep brelse from freeing busy pages. 1996-05-31 00:41:37 +00:00
John Dyson
301051a01e Make sure that we don't place a busy or held page onto the PQ_CACHE queue. 1996-05-24 05:21:58 +00:00
John Dyson
b18bfc3da7 This set of commits to the VM system does the following, and contain
contributions or ideas from Stephen McKay <syssgm@devetir.qld.gov.au>,
Alan Cox <alc@cs.rice.edu>, David Greenman <davidg@freebsd.org> and me:

	More usage of the TAILQ macros.  Additional minor fix to queue.h.
	Performance enhancements to the pageout daemon.
		Addition of a wait in the case that the pageout daemon
		has to run immediately.
		Slightly modify the pageout algorithm.
	Significant revamp of the pmap/fork code:
		1) PTE's and UPAGES's are NO LONGER in the process's map.
		2) PTE's and UPAGES's reside in their own objects.
		3) TOTAL elimination of recursive page table pagefaults.
		4) The page directory now resides in the PTE object.
		5) Implemented pmap_copy, thereby speeding up fork time.
		6) Changed the pv entries so that the head is a pointer
		   and not an entire entry.
		7) Significant cleanup of pmap_protect, and pmap_remove.
		8) Removed significant amounts of machine dependent
		   fork code from vm_glue.  Pushed much of that code into
		   the machine dependent pmap module.
		9) Support more completely the reuse of already zeroed
		   pages (Page table pages and page directories) as being
		   already zeroed.
	Performance and code cleanups in vm_map:
		1) Improved and simplified allocation of map entries.
		2) Improved vm_map_copy code.
		3) Corrected some minor problems in the simplify code.
	Implemented splvm (combo of splbio and splimp.)  The VM code now
		seldom uses splhigh.
	Improved the speed of and simplified kmem_malloc.
	Minor mod to vm_fault to avoid using pre-zeroed pages in the case
		of objects with backing objects along with the already
		existant condition of having a vnode.  (If there is a backing
		object, there will likely be a COW...  With a COW, it isn't
		necessary to start with a pre-zeroed page.)
	Minor reorg of source to perhaps improve locality of ref.
1996-05-18 03:38:05 +00:00
Poul-Henning Kamp
aa8de40ae5 Another sweep over the pmap/vm macros, this time with more focus on
the usage.  I'm not satisfied with the naming, but now at least there is
less bogus stuff around.
1996-05-03 21:01:54 +00:00
John Dyson
18ff64943e Correct handling of dirty pages in I/O buffers. The case where pages
residing in a buffer that had been dirtied by a process was being
handled incorrectly.  The pages were mistakenly placed into the
cache queue.  This would likely have the effect of mmaped page modifications
being lost when I/O system calls were being used simultaneously to
the same locations in a file.
Submitted by: davidg
1996-03-09 06:46:51 +00:00
John Dyson
c735bcf57d Fix the buffer queue problem differently. The previous fix could panic
with a buffer not on queue panic.
1996-03-03 01:04:28 +00:00
John Dyson
6538dda3dc 1) Fix a bug that a buffer is removed from a queue, but the
queue type is not set to QUEUE_NONE.  This appears to have
	caused a hang bug that has been lurking.
2)	Fix bugs that brelse'ing locked buffers do not "free" them, but the
	code assumes so.  This can cause hangs when LFS is used.
3)	Use malloced memory for directories when applicable.  The amount
	of malloced memory is seriously limited, but should decrease the
	amount of memory used by an average directory to 1/4 - 1/2 previous.
	This capability is fully tunable.  (Note that there is no config
	parameter, and might never be.)
4)	Bias slightly the buffer cache usage towards non-VMIO buffers.  Since
	the data in VMIO buffers is not lost when the buffer is reclaimed, this
	will help performance.  This is adjustable also.
1996-03-02 04:40:56 +00:00
John Dyson
91477adc6e Enable VMIO for non-VDIR metadata and block device. 1996-03-02 03:45:12 +00:00
John Dyson
bd7e5f992e Eliminated many redundant vm_map_lookup operations for vm_mmap.
Speed up for vfs_bio -- addition of a routine bqrelse to greatly diminish
	overhead for merged cache.
Efficiency improvement for vfs_cluster.  It used to do alot of redundant
	calls to cluster_rbuild.
Correct the ordering for vrele of .text and release of credentials.
Use the selective tlb update for 486/586/P6.
Numerous fixes to the size of objects allocated for files.  Additionally,
	fixes in the various pagers.
Fixes for proper positioning of vnode_pager_setsize in msdosfs and ext2fs.
Fixes in the swap pager for exhausted resources.  The pageout code
	will not as readily thrash.
Change the page queue flags (PG_ACTIVE, PG_INACTIVE, PG_FREE, PG_CACHE) into
	page queue indices (PQ_ACTIVE, PQ_INACTIVE, PQ_FREE, PQ_CACHE),
	thereby improving efficiency of several routines.
Eliminate even more unnecessary vm_page_protect operations.
Significantly speed up process forks.
Make vm_object_page_clean more efficient, thereby eliminating the pause
	that happens every 30seconds.
Make sequential clustered writes B_ASYNC instead of B_DELWRI even in the
	case of filesystems mounted async.
Fix a panic with busy pages when write clustering is done for non-VMIO
	buffers.
1996-01-19 04:00:31 +00:00
David Greenman
7548aeb5c5 Print out the queue index if it's found to be inconsistent. 1996-01-06 23:58:03 +00:00
David Greenman
2199f986f1 Rework vm_hold_{load,free}_pages to calculate an index once and use that.
At the same time, be sure to page-truncate bp->b_data so that the result
of the calculation isn't negative.
1996-01-06 23:23:02 +00:00
Garrett Wollman
8890984dc9 Convert BOUNCE_BUFFERS and BOUNCEPAGES to new option scheme. 1996-01-05 20:12:53 +00:00
David Greenman
a5782ecc36 Fixed minor struct cred leak. Discovered while looking for the opposite
condition - too many frees, which has yet to be found.

Reviewed by:	dyson
1996-01-04 06:09:00 +00:00
Poul-Henning Kamp
87b6de2b76 A Major staticize sweep. Generates a couple of warnings that I'll deal
with later.
A number of unused vars removed.
A number of unused procs removed or #ifdefed.
1995-12-14 08:32:45 +00:00
John Dyson
1cdb60485c Fix a problem that was caused by new (partial) support for merged cache
metadata and VBLK type devices.  The code is currently mostly disabled,
and a work-around has been added to disabled attempted clustered writes
for VBLK type device buffers.  Clustered write of meta-data is currently
a work in progress.
1995-12-13 03:47:01 +00:00
John Dyson
beb2f78fb0 This should have fixed some conditions that could cause the
"getblk" hang.  The B_WANTED flag was being cleared gratuitously,
also the optimization of gbincore for ignoring the B_INVAL flag was
incorrect.  There is no place in the code where buffers are on the
hash list that are B_INVAL and not B_BUSY.
1995-12-12 04:18:10 +00:00
John Dyson
a316d390bd Changes to support 1Tb filesizes. Pages are now named by an
(object,index) pair instead of (object,offset) pair.
1995-12-11 04:58:34 +00:00
David Greenman
efeaf95a41 Untangled the vm.h include file spaghetti. 1995-12-07 12:48:31 +00:00
Poul-Henning Kamp
946bb7a268 A major sweep over the sysctl stuff.
Move a lot of variables home to their own code (In good time before xmas :-)

Introduce the string descrition of format.

Add a couple more functions to poke into these marvels, while I try to
decide what the correct interface should look like.

Next is adding vars on the fly, and sysctl looking at them too.

Removed a tine bit of defunct and #ifdefed notused code in swapgeneric.
1995-12-04 16:48:58 +00:00
Bruce Evans
98d938220c Completed function declarations and/or added prototypes. 1995-12-02 18:58:56 +00:00
Bruce Evans
d841aaa740 Finished (?) cleaning up sysinit stuff. 1995-12-02 17:11:20 +00:00
John Dyson
5fe17eeb8a General fixes to the vfs clustring code:
1) Make cluster buffer list be a non-malloced chain.  This eliminates
yet another 'evil' M_WAITOK and generally cleans up the code.
2) Fix write clustering for ext2fs.  It was just broken.  Also, ffs
clustering had an efficiency problem that more bawrites were happening
than should have been.
3) Make changes to buf.h to support the above, plus remove b_pfcent
at the request of David Greenman.
Reviewed by: davidg (partially)
1995-11-19 19:54:31 +00:00
John Dyson
0ada0d6748 Added a missing splx(s). 1995-11-18 23:33:48 +00:00
John Dyson
aef922f514 Greatly simplify the msync code. Eliminate complications in vm_pageout
for msyncing.  Remove a bug that manifests itself primarily on NFS
(the dirty range on the buffers is not set on msync.)
1995-11-05 20:46:03 +00:00
Poul-Henning Kamp
a98ca4699e Second batch of cleanup changes.
This time mostly making a lot of things static and some unused
variables here and there.
1995-10-29 15:33:36 +00:00
John Dyson
6d875bf526 If we clear the B_CACHE flag because a buffer isn't composed fully of
valid bytes, we must also clear the B_DONE flag.  Some filesystems
depend on this (incl NFS) and is probably the cause of the biodone
error and subsequent crash.  Anyway this change needs to be made.
1995-10-19 23:48:25 +00:00
Steven Wallace
ad7507e248 Remove prototype definitions from <sys/systm.h>.
Prototypes are located in <sys/sysproto.h>.

Add appropriate #include <sys/sysproto.h> to files that needed
protos from systm.h.

Add structure definitions to appropriate files that relied on sys/systm.h,
right before system call definition, as in the rest of the kernel source.

In kern_prot.c, instead of using the dummy structure "args", create
individual dummy structures named <syscall>_args.  This makes
life easier for prototype generation.
1995-10-08 00:06:22 +00:00
David Greenman
7329854ac4 Two critical bugfixes:
1) "obj" was't initialized properly, resulting in an important vm_page_lookup
   always failing (resulting in a panic).
2) busy pages could be put on the cache queue or freed (resulting in a panic).
1995-10-01 05:50:27 +00:00
John Dyson
164fd96f34 These changes fix a bug in the clustering code that I made worse when adding
support for EXT2FS.  Note that the Sig-11 problems appear to be caused by
this, but there is still probably an underlying VM problem that let this
clustering bug cause vnode objects to appear to be corrupted.

The direct manifestation of this bug would have been severely mis-read
files.  It is possible that processes would Sig-11 on very damaged
input files and might explain the mysterious differences in system
behaviour when phk's malloc is being used.
1995-09-23 21:12:45 +00:00
David Greenman
4590fd3a2a Fixed init functions argument type - caddr_t -> void *. Fixed a couple of
compiler warnings.
1995-09-09 18:10:37 +00:00
John Dyson
c83ebe7781 Added VOP_GETPAGES/VOP_PUTPAGES and also the "backwards" block count
for VOP_BMAP.  Updated affected filesystems...
1995-09-04 00:21:16 +00:00
John Dyson
8c601f7da8 Improvements to the cluster code, minor vfs_bio efficiency:
Better performance -- more aggressive read-ahead
	under certain circumstanses.

	Mods to support clustering on small
	( < PAGE_SIZE) block size filesystems (e.g. ext2fs,
	msdosfs.)
1995-09-03 19:56:15 +00:00
Julian Elischer
2b14f991e6 Reviewed by: julian with quick glances by bruce and others
Submitted by:	terry (terry lambert)
This is  a composite of 3 patch sets submitted by terry.
they are:
New low-level init code that supports loadbal modules better
some cleanups in the namei code to help terry in 16-bit character support
some changes to the mount-root code to make it a little more
modular..

NOTE: mounting root off cdrom or NFS MIGHT be broken as I haven't been able
to test those cases..

certainly mounting root of disk still works just fine..
mfs should work but is untested. (tomorrows task)

The low level init stuff includes a total rewrite of init_main.c
to make it possible for new modules to have an init phase by simply
adding an entry to a TEXT_SET (or is it DATA_SET) list. thus a new module can
be added to the kernel without editing any other files other than the
'files' file.
1995-08-28 09:19:25 +00:00
David Greenman
9f95e53cff Another minor optimization, this time to incore(). 1995-08-24 13:59:14 +00:00
David Greenman
ff3aaf2582 Minor optimization. 1995-08-24 13:28:16 +00:00
David Greenman
d63abe4172 Resize both VMIO and non-VMIO buffers if the size changes. 1995-08-06 12:10:39 +00:00
Bruce Evans
28f8db1403 Eliminate sloppy common-style declarations. There should be none left for
the LINT configuation.
1995-07-29 11:44:31 +00:00
David Greenman
23953f95f6 Killed bogus casts in tsleep/wakeup calls. 1995-07-25 05:41:57 +00:00
David Greenman
cd9015557e Fixed broken offset use in vfs_unbusy_pages() which resulted in several
different types of panics/inconsistencies with NFS clients.
Cleared PG_WANTED where appropriate.
Added checks for buffer busy in allocbuf and biodone.

Reviewed by:	John Dyson
1995-07-25 05:03:06 +00:00
David Greenman
23f762689d Panic if no object in biodone. Slightly optimized allocbuf() again. 1995-07-24 03:16:41 +00:00
David Greenman
be49bd16c6 Added some additional diagnostic information output when panicing in
biodone().
1995-07-23 19:37:52 +00:00
David Greenman
31de6175b7 Fixed two cases where some parans were missing, resulting in some bogus
logic. Slightly simplified allocbuf().
1995-07-23 18:49:48 +00:00
David Greenman
44918dfed7 Re-lookup the buffer if the vnode isn't locked. The previous check for
VBLK vnodes isn't adequate since all NFS nodes aren't locked, either. The
result is a race condition that would lead to duplicate buffers at the
same block offset.

Submitted by:	John Dyson
1995-07-21 04:55:45 +00:00
David Greenman
1ce781c3af Fixed "bufspace" calculation. It was lossy in some circumstances of the
buffer resizing and caused a "newbuf" deadlock.

Reviewed by:	John Dyson & David Greenman
Submitted by:	Peter Wemm
1995-07-17 06:26:07 +00:00
David Greenman
8393c48a22 Resize buffers if they aren't the correct size. Several months ago we
made a change to NFS that caused buffers at EOF to be variable size. This
had the undesired side-effect of breaking delayed writes on NFS. This
fixes it.

Submitted by:	John Dyson
1995-07-15 16:01:46 +00:00
David Greenman
aa2cabb958 1) Converted v_vmdata to v_object.
2) Removed unnecessary vm_object_lookup()/pager_cache(object, TRUE) pairs
   after vnode_pager_alloc() calls - the object is already guaranteed to be
   persistent.
3) Removed some gratuitous casts.
1995-06-28 12:01:13 +00:00
Rodney W. Grimes
9b2e535452 Remove trailing whitespace. 1995-05-30 08:16:23 +00:00
David Greenman
61f5d51062 Changes to fix the following bugs:
1) Files weren't properly synced on filesystems other than UFS. In some
   cases, this lead to lost data. Most likely would be noticed on NFS.
   The fix is to make the VM page sync/object_clean general rather than
   in each filesystem.
2) Mixing regular and mmaped file I/O on NFS was very broken. It caused
   chunks of files to end up as zeroes rather than the intended contents.
   The fix was to fix several race conditions and to kludge up the
   "b_dirtyoff" and "b_dirtyend" that NFS relies upon - paying attention
   to page modifications that occurred via the mmapping.

Reviewed by:	David Greenman
Submitted by:	John Dyson
1995-05-21 21:39:31 +00:00
Rodney W. Grimes
b2b795f07c Fix -Wformat warnings from LINT kernel. 1995-05-11 19:26:53 +00:00
David Greenman
fc3d49a9dc Check for curproc != NULL before dereferencing it. 1995-04-30 05:09:13 +00:00
David Greenman
5baf11ce97 Removed unused & empty bufstats() function. 1995-04-16 12:02:42 +00:00
David Greenman
cece489df8 Killed gratuitous b_vp=NULL in bufinit. The entire buffer is already
bzero()'d.
1995-04-16 11:45:30 +00:00
David Greenman
d94a4c0434 1) Check for curproc != NULL in bread/bwrite. John convinced me that this
is necessary in order for panic+sync to work. Will also gloss over a panic
that Jordan was having with the install floppies that remains unexplainable.
2) Handle "bogus_page" a little better.
3) Set page protection to VM_PROT_NONE if the entire page has become !valid.

Submitted by:	John Dyson (2&3), me (1).
1995-04-16 05:11:14 +00:00
David Greenman
213fd1b6e8 Changes from John Dyson and myself:
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.
1995-04-09 06:02:46 +00:00
David Greenman
6e14d964ac Removed some redundant 'vmio' checks. 1995-03-27 00:11:45 +00:00
David Greenman
f57459b632 Removed third arg (vmio) to allocbuf() that was added with the original
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
1995-03-26 23:29:13 +00:00
Bruce Evans
b5e8ce9f12 Add and move declarations to fix all of the warnings from `gcc -Wimplicit'
(except in netccitt, netiso and netns) and most of the warnings from
`gcc -Wnested-externs'.  Fix all the bugs found.  There were no serious
ones.
1995-03-16 18:17:34 +00:00
David Greenman
5dcf309046 Removed most of the special policy regarding the seperation of VMIO and
dir/metadata buffers as it seems to have anomolous effects.
1995-03-07 19:53:27 +00:00
David Greenman
9bd1697199 Added some more of John's "anti-chatter" fixes - set the page activation
count to 0 after activating the page; the previous behavior biased the
pages too high in some cases.

Submitted by:	John Dyson
1995-03-04 15:16:07 +00:00
David Greenman
22470903a0 Fixes from John Dyson to work around vnode lock hang. Basically, remove
the VOP_BMAP calls, and add one to bdwrite.

Submitted by:	John Dyson
1995-03-03 22:13:16 +00:00
David Greenman
fde2cdc48a Various changes from John and myself that do the following:
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.
1995-03-01 22:08:55 +00:00
David Greenman
4494100855 Fixed thrashing buffer problem.
Submitted by:	John Dyson
1995-02-25 01:46:26 +00:00
David Greenman
701d45805b Added some code to make sure that buffers associated with directories and
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
1995-02-22 09:30:13 +00:00
David Greenman
7a53944444 Only do object paging_in_progress wakeups if someone is waiting on this
condition.
Added some comments.

Submitted by:	John Dyson
1995-02-22 09:16:07 +00:00
David Greenman
0e65588688 Only clear B_VMIO in brelse() - a bunch of special processing is required
whenever this happens, and that wasn't occurring in some cases.
1995-02-18 02:55:09 +00:00
David Greenman
b82c50c4e6 Make B_NOCACHE and B_INVAL buffers work correctly - throw away the data in
the page cache.

Submitted by:	John Dyson
1995-02-03 03:35:56 +00:00
David Greenman
6a1c735df7 Fix problem with freeing busy pages reported by Nick Sayer.
Submitted by:	 John Dyson
1995-01-26 03:34:31 +00:00
David Greenman
9532143ae6 Fixed a variety of deadlock and panic bugs, removed the bypass code, and
implemented the ability to limit bufferspace by memory consumed. (vfs_bio.c)
Fixed recently introduced bugs that caused extra I/O to happen in some
cases. (vfs_cluster.c)

Submitted by:	John Dyson
1995-01-24 10:00:46 +00:00
Andrey A. Chernov
60efec1dab Restore original fix from ohki, not check m for NULL it is already done
in the code above.
Submitted by: ohki@gssm.otsuka.tsukuba.ac.jp
1995-01-21 06:32:26 +00:00
Andrey A. Chernov
f76c8e8cc3 Change if (m->valid == 0) to if (m && m->valid == 0) 1995-01-20 23:30:42 +00:00
Bill Paul
fc042b6935 Submitted by: ohki@gssm.otsuka.tsukuba.ac.jp
When using cp to copy a file under the following circumstanes:

- original file in on an NFS filesystem
- destination file is on the same NFS filesystem
- the file is less than 8Mbytes in size
- the file is larger than 65536 bytes in size

the cp process can get frozen in device-wait and never wake up (cp uses
mmap() in this case).
A small change to allocbuf() fixes this.
1995-01-20 20:11:31 +00:00
David Greenman
761dd66739 Attempt to close a hole using splhigh/splx. There still appears to be a
serious one in the same area that I don't have time to fix.
1995-01-15 09:35:58 +00:00
David Greenman
c3d05da5e3 MFS doesn't bother to associate a struct mount with the vnode...so work
around this by not trying to cluster this type of I/O.

Submitted by:	John Dyson
1995-01-11 01:53:18 +00:00
David Greenman
5943df8331 PG_FAKE is no longer used - so don't bother to clear it. 1995-01-10 09:20:34 +00:00
David Greenman
480dff540b Fixed some formatting weirdness that I overlooked in the previous commit. 1995-01-10 07:32:52 +00:00
David Greenman
0d94caffca These changes embody the support of the fully coherent merged VM buffer cache,
much higher filesystem I/O performance, and much better paging performance. It
represents the culmination of over 6 months of R&D.

The majority of the merged VM/cache work is by John Dyson.

The following highlights the most significant changes. Additionally, there are
(mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to
support the new VM/buffer scheme.

vfs_bio.c:
Significant rewrite of most of vfs_bio to support the merged VM buffer cache
scheme.  The scheme is almost fully compatible with the old filesystem
interface.  Significant improvement in the number of opportunities for write
clustering.

vfs_cluster.c, vfs_subr.c
Upgrade and performance enhancements in vfs layer code to support merged
VM/buffer cache.  Fixup of vfs_cluster to eliminate the bogus pagemove stuff.

vm_object.c:
Yet more improvements in the collapse code.  Elimination of some windows that
can cause list corruption.

vm_pageout.c:
Fixed it, it really works better now.  Somehow in 2.0, some "enhancements"
broke the code.  This code has been reworked from the ground-up.

vm_fault.c, vm_page.c, pmap.c, vm_object.c
Support for small-block filesystems with merged VM/buffer cache scheme.

pmap.c vm_map.c
Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of
kernel PTs.

vm_glue.c
Much simpler and more effective swapping code.  No more gratuitous swapping.

proc.h
Fixed the problem that the p_lock flag was not being cleared on a fork.

swap_pager.c, vnode_pager.c
Removal of old vfs_bio cruft to support the past pseudo-coherency.  Now the
code doesn't need it anymore.

machdep.c
Changes to better support the parameter values for the merged VM/buffer cache
scheme.

machdep.c, kern_exec.c, vm_glue.c
Implemented a seperate submap for temporary exec string space and another one
to contain process upages. This eliminates all map fragmentation problems
that previously existed.

ffs_inode.c, ufs_inode.c, ufs_readwrite.c
Changes for merged VM/buffer cache.  Add "bypass" support for sneaking in on
busy buffers.

Submitted by:	John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
David Greenman
e03b612d87 Only VM_WAIT if curproc != pageproc. A deadlock can occur otherwise.
Submitted by:	John Dyson
1994-10-23 20:52:11 +00:00
David Greenman
08d7d166b8 Removed references to bclnlist which we don't use/support/need. 1994-10-18 06:55:57 +00:00
David Greenman
8e58bf6875 Stuff object into v_vmdata rather than pager. Not important which at
the moment, but will be in the future. Other changes mostly cosmetic,
but are made for future VMIO considerations.

Submitted by:	John Dyson
1994-10-05 09:48:45 +00:00
David Greenman
91b1e28556 Commented out anti-paging code as it was found to be the cause of a
buffer deadlock.
1994-10-04 03:10:47 +00:00
Poul-Henning Kamp
bb56ec4a05 While in the real world, I had a bad case of being swapped out for a lot of
cycles.  While waiting there I added a lot of the extra ()'s I have, (I have
never used LISP to any extent).  So I compiled the kernel with -Wall and
shut up a lot of "suggest you add ()'s", removed a bunch of unused var's
and added a couple of declarations here and there.  Having a lap-top is
highly recommended.  My kernel still runs, yell at me if you kernel breaks.
1994-09-25 19:34:02 +00:00
David Greenman
9aba88bf29 Rather than exclude bounce buffers support with NOBOUNCE, include it
with BOUNCE_BUFFERS. This is more intuitive, and is better for future
multiplatform support. Added BOUNCE_BUFFERS option to the GENERIC and
LINT kernel config files.
1994-08-31 06:17:49 +00:00
David Greenman
e66defe8ab Changed to reclaim memory from other buffers to eliminate memory
thrashing.

Submitted by:	John Dyson
1994-08-30 18:19:11 +00:00
Garrett Wollman
f23b4c91c4 Fix up some sloppy coding practices:
- Delete redundant declarations.
- Add -Wredundant-declarations to Makefile.i386 so they don't come back.
- Delete sloppy COMMON-style declarations of uninitialized data in
  header files.
- Add a few prototypes.
- Clean up warnings resulting from the above.

NB: ioconf.c will still generate a redundant-declaration warning, which
is unavoidable unless somebody volunteers to make `config' smarter.
1994-08-18 22:36:09 +00:00
Garrett Wollman
57034e7407 Run-time configuration of VFS update interval. Old UPDATE_INTERVAL
configuration option is no longer supported.
1994-08-08 15:41:08 +00:00
David Greenman
8339815ff9 Made pmap_kenter "TLB safe". ...and then removed all the pmap_updates that
are no longer needed because of this.
1994-08-07 14:53:27 +00:00
David Greenman
16f62314cd Incorporated post 1.1.5 work from John Dyson. This includes performance
improvements via the new routines pmap_qenter/pmap_qremove and pmap_kenter/
pmap_kremove. These routine allow fast mapping of pages for those
architectures that have "normal" MMUs. Also included is a fix to the
pageout daemon to properly check a queue end condition.

Submitted by:	John Dyson
1994-08-06 09:15:42 +00:00
David Greenman
ce921c90fd Fixed bug that would cause free memory reserves to be depleted and cause a
panic in some cases.
Submitted by:	John Dyson
1994-08-04 19:43:13 +00:00
David Greenman
3c4dd3568f Added $Id$ 1994-08-02 07:55:43 +00:00
David Greenman
594110fe18 Moved header definitions to buf.h, and added missing splx() - found
by Johannes Helander.
1994-05-26 08:45:29 +00:00
Rodney W. Grimes
26f9a76710 The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch.
Reviewed by:	Rodney W. Grimes
Submitted by:	John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
Rodney W. Grimes
df8bae1de4 BSD 4.4 Lite Kernel Sources 1994-05-24 10:09:53 +00:00