Commit Graph

127 Commits

Author SHA1 Message Date
Matthew Dillon
fe8e0238cc Fix deadlock introduced in 1.73 (Jan 1998). The paging-in-progress count
on a vnode-backed object must be incremented *after* obtaining the vnode
lock.  If it is bumped before obtaining the vnode lock we can deadlock
against vtruncbuf().

Submitted by:	peter, ps
MFC after:	3 days
2001-11-09 21:34:45 +00:00
Matthew Dillon
245df27cee Implement kern.maxvnodes. adjusting kern.maxvnodes now actually has a
real effect.

Optimize vfs_msync().  Avoid having to continually drop and re-obtain
mutexes when scanning the vnode list.  Improves looping case by 500%.

Optimize ffs_sync().  Avoid having to continually drop and re-obtain
mutexes when scanning the vnode list.  This makes a couple of assumptions,
which I believe are ok, in regards to vnode stability when the mount list
mutex is held.  Improves looping case by 500%.

(more optimization work is needed on top of these fixes)

MFC after:	1 week
2001-10-26 00:08:05 +00:00
Julian Elischer
b40ce4165d KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after:    ha ha ha ha
2001-09-12 08:38:13 +00:00
Matthew Dillon
6d03d577a5 Reorg vm_page.c into vm_page.c, vm_pageq.c, and vm_contig.c (for contigmalloc).
Also removed some spl's and added some VM mutexes, but they are not actually
used yet, so this commit does not really make any operational changes
to the system.

vm_page.c relates to vm_page_t manipulation, including high level deactivation,
activation, etc...  vm_pageq.c relates to finding free pages and aquiring
exclusive access to a page queue (exclusivity part not yet implemented).
And the world still builds... :-)
2001-07-04 23:27:09 +00:00
Matthew Dillon
54d9214595 whitespace / register cleanup 2001-07-04 19:00:13 +00:00
Matthew Dillon
0cddd8f023 With Alfred's permission, remove vm_mtx in favor of a fine-grained approach
(this commit is just the first stage).  Also add various GIANT_ macros to
formalize the removal of Giant, making it easy to test in a more piecemeal
fashion. These macros will allow us to test fine-grained locks to a degree
before removing Giant, and also after, and to remove Giant in a piecemeal
fashion via sysctl's on those subsystems which the authors believe can
operate without Giant.
2001-07-04 16:20:28 +00:00
John Baldwin
576f0c5fa4 Take a more conservative approach and still lock Giant around VM faults
for now.
2001-05-23 22:09:18 +00:00
John Baldwin
4edf4a58e6 Sort includes. 2001-05-22 00:56:25 +00:00
Alfred Perlstein
2395531439 Introduce a global lock for the vm subsystem (vm_mtx).
vm_mtx does not recurse and is required for most low level
vm operations.

faults can not be taken without holding Giant.

Memory subsystems can now call the base page allocators safely.

Almost all atomic ops were removed as they are covered under the
vm mutex.

Alpha and ia64 now need to catch up to i386's trap handlers.

FFS and NFS have been tested, other filesystems will need minor
changes (grabbing the vm lock when twiddling page properties).

Reviewed (partially) by: jake, jhb
2001-05-19 01:28:09 +00:00
Mark Murray
fb919e4d5a Undo part of the tangle of having sys/lock.h and sys/mutex.h included in
other "system" header files.

Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.

Sort sys/*.h includes where possible in affected files.

OK'ed by:	bde (with reservations)
2001-05-01 08:13:21 +00:00
Matthew Dillon
b823bbd6be Fix a lock reversal problem in the VM subsystem related to threaded
programs.   There is a case during a fork() which can cause a deadlock.

From Tor -
The workaround that consists of setting a flag in the vm map that
indicates that a fork is in progress and using that mark in the page
fault handling to force a revalidation failure.  That change will only
affect (pessimize) page fault handling during fork for threaded
(linuxthreads style) applications and applications using aio_*().

Submited by: tegge
2001-03-14 06:48:53 +00:00
Matthew Dillon
5bf53acb74 If we intend to make the page writable without requiring another fault,
make sure that PG_NOSYNC is properly set.  Previously we only set it
for a write-fault, but this can occur on a read-fault too.
(will be MFCd prior to 4.3 freeze)
2001-02-28 04:26:43 +00:00
Bosko Milekic
9ed346bab0 Change and clean the mutex lock interface.
mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)
2001-02-09 06:11:45 +00:00
John Baldwin
b939335607 - Catch up to proc flag changes. 2001-01-24 11:20:05 +00:00
Matthew Dillon
ef0646f9d8 Add the splvm()'s suggested in PR 20609 to protect vm_pager_page_unswapped().
The remainder of the PR is still open.

PR: kern/20609 (partial fix)
2000-11-18 21:11:23 +00:00
Matthew Dillon
8b03c8ed5e This is a cleanup patch to Peter's new OBJT_PHYS VM object type
and sysv shared memory support for it.  It implements a new
    PG_UNMANAGED flag that has slightly different characteristics
    from PG_FICTICIOUS.

    A new sysctl, kern.ipc.shm_use_phys has been added to enable the
    use of physically-backed sysv shared memory rather then swap-backed.
    Physically backed shm segments are not tracked with PV entries,
    allowing programs which use a large shm segment as a rendezvous
    point to operate without eating an insane amount of KVM in the
    PV entry management.  Read: Oracle.

    Peter's OBJT_PHYS object will also allow us to eventually implement
    page-table sharing and/or 4MB physical page support for such segments.
    We're half way there.
2000-05-29 22:40:54 +00:00
Peter Wemm
0385347c1a Implement an optimization of the VM<->pmap API. Pass vm_page_t's directly
to various pmap_*() functions instead of looking up the physical address
and passing that.  In many cases, the first thing the pmap code was doing
was going to a lot of trouble to get back the original vm_page_t, or
it's shadow pv_table entry.

Inspired by: John Dyson's 1998 patches.

Also:
Eliminate pv_table as a seperate thing and build it into a machine
dependent part of vm_page_t.  This eliminates having a seperate set of
structions that shadow each other in a 1:1 fashion that we often went to
a lot of trouble to translate from one to the other. (see above)
This happens to save 4 bytes of physical memory for each page in the
system.  (8 bytes on the Alpha).

Eliminate the use of the phys_avail[] array to determine if a page is
managed (ie: it has pv_entries etc).  Store this information in a flag.
Things like device_pager set it because they create vm_page_t's on the
fly that do not have pv_entries.  This makes it easier to "unmanage" a
page of physical memory (this will be taken advantage of in subsequent
commits).

Add a function to add a new page to the freelist.  This could be used
for reclaiming the previously wasted pages left over from preloaded
loader(8) files.

Reviewed by:	dillon
2000-05-21 12:50:18 +00:00
Philippe Charnier
5929bcfaba Revert spelling mistake I made in the previous commit
Requested by: Alan and Bruce
2000-03-27 20:41:17 +00:00
Philippe Charnier
956f31353c Spelling 2000-03-26 15:20:23 +00:00
Matthew Dillon
4f79d873c1 Add MAP_NOSYNC feature to mmap(), and MADV_NOSYNC and MADV_AUTOSYNC to
madvise().

    This feature prevents the update daemon from gratuitously flushing
    dirty pages associated with a mapped file-backed region of memory.  The
    system pager will still page the memory as necessary and the VM system
    will still be fully coherent with the filesystem.  Modifications made
    by other means to the same area of memory, for example by write(), are
    unaffected.  The feature works on a page-granularity basis.

    MAP_NOSYNC allows one to use mmap() to share memory between processes
    without incuring any significant filesystem overhead, putting it in
    the same performance category as SysV Shared memory and anonymous memory.

Reviewed by: julian, alc, dg
1999-12-12 03:19:33 +00:00
Poul-Henning Kamp
923502ff91 useracc() the prequel:
Merge the contents (less some trivial bordering the silly comments)
of <vm/vm_prot.h> and <vm/vm_inherit.h> into <vm/vm.h>.  This puts
the #defines for the vm_inherit_t and vm_prot_t types next to their
typedefs.

This paves the road for the commit to follow shortly: change
useracc() to use VM_PROT_{READ|WRITE} rather than B_{READ|WRITE}
as argument.
1999-10-29 18:09:36 +00:00
Matthew Dillon
40360b1bbb Final commit to remove vnode->v_lastr. vm_fault now handles read
clustering issues (replacing code that used to be in
    ufs/ufs/ufs_readwrite.c).  vm_fault also now uses the new VM page counter
    inlines.

    This completes the changeover from vnode->v_lastr to vm_entry_t->v_lastr
    for VM, and fp->f_nextread and fp->f_seqcount (which have been in the
    tree for a while).  Determination of the I/O strategy (sequential, random,
    and so forth) is now handled on a descriptor-by-descriptor basis for
    base I/O calls, and on a memory-region-by-memory-region and
    process-by-process basis for VM faults.

Reviewed by:	David Greenman <dg@root.com>, Alan Cox <alc@cs.rice.edu>
1999-09-21 00:36:16 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Alan Cox
7f866e4b29 Move the memory access behavior information provided by madvise
from the vm_object to the vm_map.

Submitted by:	dillon
1999-08-01 06:05:09 +00:00
Alan Cox
ca06c247ba Convert a "page not busy" warning to an assertion.
Submitted by:	dillon@backplane.com
1999-07-20 05:46:56 +00:00
Alan Cox
4221e284a3 The VFS/BIO subsystem contained a number of hacks in order to optimize
piecemeal, middle-of-file writes for NFS.  These hacks have caused no
end of trouble, especially when combined with mmap().  I've removed
them.  Instead, NFS will issue a read-before-write to fully
instantiate the struct buf containing the write.  NFS does, however,
optimize piecemeal appends to files.  For most common file operations,
you will not notice the difference.  The sole remaining fragment in
the VFS/BIO system is b_dirtyoff/end, which NFS uses to avoid cache
coherency issues with read-merge-write style operations.  NFS also
optimizes the write-covers-entire-buffer case by avoiding the
read-before-write.  There is quite a bit of room for further
optimization in these areas.

The VM system marks pages fully-valid (AKA vm_page_t->valid =
VM_PAGE_BITS_ALL) in several places, most noteably in vm_fault.  This
is not correct operation.  The vm_pager_get_pages() code is now
responsible for marking VM pages all-valid.  A number of VM helper
routines have been added to aid in zeroing-out the invalid portions of
a VM page prior to the page being marked all-valid.  This operation is
necessary to properly support mmap().  The zeroing occurs most often
when dealing with file-EOF situations.  Several bugs have been fixed
in the NFS subsystem, including bits handling file and directory EOF
situations and buf->b_flags consistancy issues relating to clearing
B_ERROR & B_INVAL, and handling B_DONE.

getblk() and allocbuf() have been rewritten.  B_CACHE operation is now
formally defined in comments and more straightforward in
implementation.  B_CACHE for VMIO buffers is based on the validity of
the backing store.  B_CACHE for non-VMIO buffers is based simply on
whether the buffer is B_INVAL or not (B_CACHE set if B_INVAL clear,
and vise-versa).  biodone() is now responsible for setting B_CACHE
when a successful read completes.  B_CACHE is also set when a bdwrite()
is initiated and when a bwrite() is initiated.  VFS VOP_BWRITE
routines (there are only two - nfs_bwrite() and bwrite()) are now
expected to set B_CACHE.  This means that bowrite() and bawrite() also
set B_CACHE indirectly.

There are a number of places in the code which were previously using
buf->b_bufsize (which is DEV_BSIZE aligned) when they should have
been using buf->b_bcount.  These have been fixed.  getblk() now clears
B_DONE on return because the rest of the system is so bad about
dealing with B_DONE.

Major fixes to NFS/TCP have been made.  A server-side bug could cause
requests to be lost by the server due to nfs_realign() overwriting
other rpc's in the same TCP mbuf chain.  The server's kernel must be
recompiled to get the benefit of the fixes.

Submitted by:	Matthew Dillon <dillon@apollo.backplane.com>
1999-05-02 23:57:16 +00:00
Alan Cox
14286e5e8f Reviewed by: Matthew Dillon <dillon@apollo.backplane.com>
Corrected the computation of cnt.v_ozfod in vm_fault: vm_fault
was counting the number of unoptimized rather than optimized
zero-fill faults.
1999-02-25 06:00:52 +00:00
Matthew Dillon
b33fb764f1 Submitted by: Luoqi Chen <luoqi@watermarkgroup.com>
Unlock vnode before messing with map to avoid deadlock between map and
    vnode ( e.g. with exec_map and underlying program binary vnode ).  Solves
    a deadlock that most often occurs during a large -j# buildworld reported
    by three people.
1999-02-17 09:08:29 +00:00
Matthew Dillon
9fdfe602fc Remove MAP_ENTRY_IS_A_MAP 'share' maps. These maps were once used to
attempt to optimize forks but were essentially given-up on due to
    problems and replaced with an explicit dup of the vm_map_entry structure.
    Prior to the removal, they were entirely unused.
1999-02-07 21:48:23 +00:00
Matthew Dillon
7dbf82dc13 Change all manual settings of vm_page_t->dirty = VM_PAGE_BITS_ALL
to use the vm_page_dirty() inline.

    The inline can thus do sanity checks ( or not ) over all cases.
1999-01-24 06:04:52 +00:00
Matthew Dillon
bc6d84a6a3 Get rid of unused old_m in vm_fault. Add INVARIANTS to test whether
page is still busy after all the hell vm_fault goes through.. it is
    supposed to be, and printf() if it isn't.  don't panic, though.
1999-01-24 00:55:04 +00:00
Matthew Dillon
7615edaa49 Reenable John Dyson's low-memory VM_WAIT code for page reactivations out
of PQ_CACHE.  Add comments explaining what it accomplishes and its
    limitations.
1999-01-23 06:00:27 +00:00
Matthew Dillon
4c23ae0916 Mainly cleanup. Removed some inappropriate low-memory handling code
and added lots of comments.  Add tie-in to vm_pager ( and thus the
    new swapper ) to deallocate backing swap for dirtied pages on the fly.
1999-01-21 09:35:38 +00:00
Matthew Dillon
1c7c3c6a86 This is a rather large commit that encompasses the new swapper,
changes to the VM system to support the new swapper, VM bug
    fixes, several VM optimizations, and some additional revamping of the
    VM code.  The specific bug fixes will be documented with additional
    forced commits.  This commit is somewhat rough in regards to code
    cleanup issues.

Reviewed by:	"John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
Eivind Eklund
219cbf59f2 KNFize, by bde. 1999-01-10 01:58:29 +00:00
Eivind Eklund
5526d2d920 Split DIAGNOSTIC -> DIAGNOSTIC, INVARIANTS, and INVARIANT_SUPPORT as
discussed on -hackers.

Introduce 'KASSERT(assertion, ("panic message", args))' for simple
check + panic.

Reviewed by:	msmith
1999-01-08 17:31:30 +00:00
David Greenman
c699f45e35 Add missing splvm protection around unqueue call. Without this, the page
queues would eventually get corrupted.
1998-11-25 07:40:49 +00:00
David Greenman
730075613a Added a second argument, "activate" to the vm_page_unwire() call so that
the caller can select either inactive or active queue to put the page on.
1998-10-28 13:37:02 +00:00
Poul-Henning Kamp
f5ef029e92 Nitpicking and dusting performed on a train. Removes trivial warnings
about unused variables, labels and other lint.
1998-10-25 17:44:59 +00:00
Doug Rabson
e69763a315 Cosmetic changes to the PAGE_XXX macros to make them consistent with
the other objects in vm.
1998-09-04 08:06:57 +00:00
Doug Rabson
069e9bc1b4 Change various syscalls to use size_t arguments instead of u_int.
Add some overflow checks to read/write (from bde).

Change all modifications to vm_page::flags, vm_page::busy, vm_object::flags
and vm_object::paging_in_progress to use operations which are not
interruptable.

Reviewed by: Bruce Evans <bde@zeta.org.au>
1998-08-24 08:39:39 +00:00
Doug Rabson
d474eaaa5f Protect all modifications to paging_in_progress with splvm(). The i386
managed to avoid corruption of this variable by luck (the compiler used a
memory read-modify-write instruction which wasn't interruptable) but other
architectures cannot.

With this change, I am now able to 'make buildworld' on the alpha (sfx: the
crowd goes wild...)
1998-08-06 08:33:19 +00:00
David Greenman
f3679e351a Improved pager input failure message. 1998-07-22 09:38:04 +00:00
Bruce Evans
92c4c4eb52 Fixed printf format errors. 1998-07-11 12:07:52 +00:00
John Dyson
cbd8ec0902 Work around some VM bugs, the worst being an overly aggressive
swap space free calculation.  More complete fixes will be forthcoming,
in a week.
1998-05-04 03:01:44 +00:00
John Dyson
4866e0856c Make vm_fault much cleaner by removing the evil macro inlines, and
put alot of it's context into a data structure.  This allows
significant shortening of its codepath, and will significantly
decrease it's cache footprint.

Also, add some stats to vmmeter.  Note that you'll have to
rebuild/recompile vmstat, systat, etc... Otherwise, you'll
get "very interesting" paging stats.
1998-03-07 20:45:47 +00:00
John Dyson
ffc82b0a70 1) Use a more consistent page wait methodology.
2)	Do not unnecessarily force page blocking when paging
	pages out.
3)	Further improve swap pager performance and correctness,
	including fixing the paging in progress deadlock (except
	in severe I/O error conditions.)
4)	Enable vfs_ioopt=1 as a default.
5)	Fix and enable the page prezeroing in SMP mode.

All in all, SMP systems especially should show a significant
improvement in "snappyness."
1998-03-01 04:18:54 +00:00
Eivind Eklund
303b270b0a Staticize. 1998-02-09 06:11:36 +00:00
Eivind Eklund
0b08f5f737 Back out DIAGNOSTIC changes. 1998-02-06 12:14:30 +00:00
Eivind Eklund
47cfdb166d Turn DIAGNOSTIC into a new-style option. 1998-02-04 22:34:03 +00:00