Commit Graph

85 Commits

Author SHA1 Message Date
bde
38a74a7bc2 Eliminate sloppy common-style declarations. There should be none left for
the LINT configuation.
1995-07-29 11:44:31 +00:00
dg
b8e783516f vnode_pager_alloc() never returns NULL, so don't check for it. 1995-07-20 09:43:12 +00:00
dg
c8b0a7332c NOTE: libkvm, w, ps, 'top', and any other utility which depends on struct
proc or any VM system structure will have to be rebuilt!!!

Much needed overhaul of the VM system. Included in this first round of
changes:

1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages,
   haspage, and sync operations are supported. The haspage interface now
   provides information about clusterability. All pager routines now take
   struct vm_object's instead of "pagers".

2) Improved data structures. In the previous paradigm, there is constant
   confusion caused by pagers being both a data structure ("allocate a
   pager") and a collection of routines. The idea of a pager structure has
   escentially been eliminated. Objects now have types, and this type is
   used to index the appropriate pager. In most cases, items in the pager
   structure were duplicated in the object data structure and thus were
   unnecessary. In the few cases that remained, a un_pager structure union
   was created in the object to contain these items.

3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now
   be removed. For instance, vm_object_enter(), vm_object_lookup(),
   vm_object_remove(), and the associated object hash list were some of the
   things that were removed.

4) simple_lock's removed. Discussion with several people reveals that the
   SMP locking primitives used in the VM system aren't likely the mechanism
   that we'll be adopting. Even if it were, the locking that was in the code
   was very inadequate and would have to be mostly re-done anyway. The
   locking in a uni-processor kernel was a no-op but went a long way toward
   making the code difficult to read and debug.

5) Places that attempted to kludge-up the fact that we don't have kernel
   thread support have been fixed to reflect the reality that we are really
   dealing with processes, not threads. The VM system didn't have complete
   thread support, so the comments and mis-named routines were just wrong.
   We now use tsleep and wakeup directly in the lock routines, for instance.

6) Where appropriate, the pagers have been improved, especially in the
   pager_alloc routines. Most of the pager_allocs have been rewritten and
   are now faster and easier to maintain.

7) The pagedaemon pageout clustering algorithm has been rewritten and
   now tries harder to output an even number of pages before and after
   the requested page. This is sort of the reverse of the ideal pagein
   algorithm and should provide better overall performance.

8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup
   have been removed. Some other unnecessary casts have also been removed.

9) Some almost useless debugging code removed.

10) Terminology of shadow objects vs. backing objects straightened out.
    The fact that the vm_object data structure escentially had this
    backwards really confused things. The use of "shadow" and "backing
    object" throughout the code is now internally consistent and correct
    in the Mach terminology.

11) Several minor bug fixes, including one in the vm daemon that caused
    0 RSS objects to not get purged as intended.

12) A "default pager" has now been created which cleans up the transition
    of objects to the "swap" type. The previous checks throughout the code
    for swp->pg_data != NULL were really ugly. This change also provides
    the rudiments for future backing of "anonymous" memory by something
    other than the swap pager (via the vnode pager, for example), and it
    allows the decision about which of these pagers to use to be made
    dynamically (although will need some additional decision code to do
    this, of course).

13) (dyson) MAP_COPY has been deprecated and the corresponding "copy
    object" code has been removed. MAP_COPY was undocumented and non-
    standard. It was furthermore broken in several ways which caused its
    behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will
    continue to work correctly, but via the slightly different semantics
    of MAP_PRIVATE.

14) (dyson) Sharing maps have been removed. It's marginal usefulness in a
    threads design can be worked around in other ways. Both #12 and #13
    were done to simplify the code and improve readability and maintain-
    ability. (As were most all of these changes)

TODO:

1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing
   this will reduce the vnode pager to a mere fraction of its current size.

2) Rewrite vm_fault and the swap/vnode pagers to use the clustering
   information provided by the new haspage pager interface. This will
   substantially reduce the overhead by eliminating a large number of
   VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be
   improved to provide both a "behind" and "ahead" indication of
   contiguousness.

3) Implement the extended features of pager_haspage in swap_pager_haspage().
   It currently just says 0 pages ahead/behind.

4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps
   via a much more general mechanism that could also be used for disk
   striping of regular filesystems.

5) Do something to improve the architecture of vm_object_collapse(). The
   fact that it makes calls into the swap pager and knows too much about
   how the swap pager operates really bothers me. It also doesn't allow
   for collapsing of non-swap pager objects ("unnamed" objects backed by
   other pagers).
1995-07-13 08:48:48 +00:00
dg
24d64ff84a Moved call to VOP_GETATTR() out of vnode_pager_alloc() and into the places
that call vnode_pager_alloc() so that a failure return can be dealt with.
This fixes a panic seen on NFS clients when a file being opened is deleted
on the server before the open completes.
1995-07-09 06:58:03 +00:00
dg
3c7c1dd62f 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
dg
5d0d9f974b Fixed VOP_LINK argument order botch. 1995-06-28 07:06:55 +00:00
dfr
666343f7f0 Changes to support version 3 of the NFS protocol.
The version 2 support has been tested (client+server) against FreeBSD-2.0,
IRIX 5.3 and FreeBSD-current (using a loopback mount).  The version 2 support
is stable AFAIK.
The version 3 support has been tested with a loopback mount and minimally
against an IRIX 5.3 server.  It needs more testing and may have problems.
I have patched amd to support the new variable length filehandles although
it will still only use version 2 of the protocol.

Before booting a kernel with these changes, nfs clients will need to at least
build and install /usr/sbin/mount_nfs.  Servers will need to build and
install /usr/sbin/mountd.

NFS diskless support is untested.

Obtained from: Rick Macklem <rick@snowhite.cis.uoguelph.ca>
1995-06-27 11:07:30 +00:00
joerg
1c9ad9c342 The duplicate information returned in fa_type and fa_mode
is an ambiguity in the NFS version 2 protocol.

VREG should be taken literally as a regular file.  If a
server intents to return some type information differently
in the upper bits of the mode field (e.g. for sockets, or
FIFOs), NFSv2 mandates fa_type to be VNON.  Anyway, we
leave the examination of the mode bits even in the VREG
case to avoid breakage for bogus servers, but we make sure
that there are actually type bits set in the upper part of
fa_mode (and failing that, trust the va_type field).

NFSv3 cleared the issue, and requires fa_mode to not
contain any type information (while also introduing sockets
and FIFOs for fa_type).

The fix has been tested against a variety of NFS servers.
It fixes problems with the ``Tropic'' NFS server for Windows,
while apparently not breaking anything.

Pointed-out by: scott@zorch.sf-bay.org (Scott Hazen Mueller)
1995-06-14 06:23:38 +00:00
rgrimes
1b1ee55538 Merge RELENG_2_0_5 into HEAD 1995-06-11 19:33:05 +00:00
rgrimes
c86f0c7a71 Remove trailing whitespace. 1995-05-30 08:16:23 +00:00
dg
da17d8251a Fixed some serious bugs that resulted in object reference counts not being
handled correctly. This would manifest itself as "object deallocated too
many times" panics and perhaps other strange inconsistencies on NFS servers.

Reviewed by:	me, of course
Submitted by:	John Dyson
1995-05-29 04:01:09 +00:00
dyson
20f29bf525 Slight re-ordering of the creation of a vmio object to fix a condition
that can cause NFS I/O failures.
1995-04-21 02:58:49 +00:00
dg
fa7269fdef Removed unnecessary call to vnode_pager_uncache(). We automatically clear
the VTEXT flag after all mappers have finished with the object.
1995-03-19 12:08:03 +00:00
dg
ca2e4bfc64 Changed some (incorrect) nfsrv_vput()'s back into regular vput()'s. This
fixes the last of the known NQNFS problems (until I find more, that is :-)).
1995-03-17 07:45:19 +00:00
bde
289f11acb4 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
phk
5911bb0d89 YF fix. 1995-02-15 04:21:32 +00:00
dg
65ebc47880 Fixed two more bugs related to the merged cache changes.
Submitted by:	John Dyson
1995-02-15 03:40:00 +00:00
dg
0e8333d2b1 Woops, change a nfsrv_vput back into a nfsrv_vrele.
Submitted by:	John Dyson
1995-02-15 03:38:12 +00:00
dg
01a43e3165 Fixed three bugs related to the merged cache changes. The bugs likely would
make NFS servers flakey - probably the cause of freefall's recent hangs.

Submitted by:	John Dyson
1995-02-15 03:03:03 +00:00
phk
90c55d5f1c YFfix
+int    nfsrv_vput __P(( struct vnode * ));
+int    nfsrv_vrele __P(( struct vnode * ));
+int    nfsrv_vmio __P(( struct vnode * ));
1995-02-14 06:22:18 +00:00
dg
977da6cc01 Changed order of release of vnode/object to fix a problem where the vnode
is freed with an old object still attached (subsequently causing a panic).
Fixes NFS server panic "object/pager mismatch".

Submitted by:	John Dyson
1995-02-06 02:20:40 +00:00
dg
1707d41102 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
wollman
c6477bf5ea Forward-declare a few structures to avoid warning messages. 1994-11-02 00:11:00 +00:00
wollman
a9f28ccb91 Implement fs.nfs MIB variables. 1994-10-23 23:26:18 +00:00
phk
071d10f334 This is a bunch of changes from NetBSD. There are a couple of bug-fixes.
But mostly it is changes to use the list-maintenance macros instead of
doing the pointer-gymnastics by hand.

Obtained from: NetBSD
1994-10-17 17:47:45 +00:00
phk
42a70cf15d Prototyping and general gcc-shutting up. Gcc has one warning now which looks
bad, I will get to it eventually, unless somebody beats me to it.
1994-10-02 17:27:07 +00:00
dfr
57b6c0c34c Make NFS ask the filesystems for directory cookies instead of making them
itself.
1994-09-28 16:45:22 +00:00
wollman
d8d853f4fa Make NFS loadable. 1994-09-22 22:10:49 +00:00
wollman
900d29807d More loadable VFS changes:
- Make a number of filesystems work again when they are statically compiled
  (blush)

- FIFOs are no longer optional; ``options FIFO'' removed from distributed
  config files.
1994-09-22 19:38:41 +00:00
dg
f15c464e97 "bogus" fixes from 1.1.5 to work around some cache coherency problems. 1994-08-29 06:09:15 +00:00
paul
9e34f0cb59 More idempotency....... this is fun :-) 1994-08-21 06:50:16 +00:00
dg
7c5373446c Made NFS attribute cache timeouts kernel config file tunable via
NFS_MINATTRTIMO and NFS_MAXATTRTIMO.
1994-08-04 06:03:46 +00:00
dg
8d205697aa Added $Id$ 1994-08-02 07:55:43 +00:00
rgrimes
2469c867a1 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
rgrimes
27464aaa8e BSD 4.4 Lite Kernel Sources 1994-05-24 10:09:53 +00:00