Commit Graph

61 Commits

Author SHA1 Message Date
Alfred Perlstein
305dd591ee Fix the botched rev 1.59 where I made it such that without INVARIANTS
the map is never locked.

Submitted by: tegge
2001-04-18 05:30:24 +00:00
Alfred Perlstein
493607117e use %p for pointer printf, include sys/systm.h for printf proto 2001-04-13 10:22:14 +00:00
Alfred Perlstein
7d26b6a450 Use a macro wrapper over printf along with KASSERT to reduce the amount
of code here.
2001-04-13 08:07:37 +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
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
Jason Evans
9722d88fba For lockmgr mutex protection, use an array of mutexes that are allocated
and initialized during boot.  This avoids bloating sizeof(struct lock).
As a side effect, it is no longer necessary to enforce the assumtion that
lockinit()/lockdestroy() calls are paired, so the LK_VALID flag has been
removed.

Idea taken from:	BSD/OS.
2000-10-12 22:37:28 +00:00
Jason Evans
a18b1f1d4d Convert lockmgr locks from using simple locks to using mutexes.
Add lockdestroy() and appropriate invocations, which corresponds to
lockinit() and must be called to clean up after a lockmgr lock is no
longer needed.
2000-10-04 01:29:17 +00:00
Paul Saab
9730a5daab Add MAP_NOCORE to mmap(2), and MADV_NOCORE and MADV_CORE to madvise(2).
This
This feature allows you to specify if mmap'd data is included in
an application's corefile.

Change the type of eflags in struct vm_map_entry from u_char to
vm_eflags_t (an unsigned int).

Reviewed by:	dillon,jdp,alfred
Approved by:	jkh
2000-02-28 04:10:35 +00:00
Peter Wemm
c447342094 Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot).  This is consistant with the other
BSD's who made this change quite some time ago.  More commits to come.
1999-12-29 05:07:58 +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
Matthew Dillon
b430905573 cleanup madvise code, add a few more sanity checks.
Reviewed by:	Alan Cox <alc@cs.rice.edu>,  dg@root.com
1999-09-21 05:00:48 +00:00
Matthew Dillon
3f873b513b Add 'lastr' field to vm_map_entry in preparation for its removal
from the vnode.  (The changeover is undergoing final testing and
    will be committed soon).

Reviewed by:	Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:40:17 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Alan Cox
e394748e8e Correct the inconsistent formatting in struct vm_map.
Addendum to rev 1.47: submitted by dillon.
1999-08-23 18:16:05 +00:00
Alan Cox
b7d742995e struct vm_map:
The lock structure cannot be the first element of the vm_map
	because this can result in livelock between two or more system
	processes trying to kmem_alloc_wait.
1999-08-23 18:08:34 +00:00
Matt Jacob
c531b7fc1f Fix breakage - an extra brace got inserted where DIAGNOSTIC was defined
but MAP_LOCK_DIAGNOSTIC wasn't.
1999-08-18 03:56:57 +00:00
Alan Cox
557582141f vm_map_lock*:
Remove semicolons or add "do { } while (0)" as necessary
	to enable the use of these macros in arbitrary statements.
	(There are no functional changes.)

Submitted by:	dillon
1999-08-16 18:21:09 +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
cae826d0de Remove unused function prototypes. 1999-07-10 18:16:08 +00:00
Alan Cox
6ea5bd80fe Remove some unused function and variable declarations. 1999-06-19 18:42:53 +00:00
Alan Cox
e972780a11 Add the options MAP_PREFAULT and MAP_PREFAULT_PARTIAL to vm_map_find/insert,
eliminating the need for the pmap_object_init_pt calls in imgact_* and
mmap.

Reviewed by:	David Greenman <dg@root.com>
1999-05-17 00:53:56 +00:00
Alan Cox
ea41812fe5 Remove prototypes for functions that don't exist anymore (vm_map.h).
Remove a useless argument from vm_map_madvise's interface (vm_map.c,
	vm_map.h, and vm_mmap.c).

Remove a redundant test in vm_uiomove (vm_map.c).

Make two changes to vm_object_coalesce:

1. Determine whether the new range of pages actually overlaps
the existing object's range of pages before calling vm_object_page_remove.
(Prior to this change almost 90% of the calls to vm_object_page_remove
were to remove pages that were beyond the end of the object.)

2. Free any swap space allocated to removed pages.
1999-05-16 05:07:34 +00:00
Alan Cox
e5f13bdd09 Simplify vm_map_find/insert's interface: remove the MAP_COPY_NEEDED option.
It never makes sense to specify MAP_COPY_NEEDED without also specifying
MAP_COPY_ON_WRITE, and vice versa.  Thus, MAP_COPY_ON_WRITE suffices.

Reviewed by:	David Greenman <dg@root.com>
1999-05-14 23:09:34 +00:00
Alan Cox
f59e8eb9b1 Upgrading a map's lock to exclusive status should increment
the map's timestamp.  In general, whenever an exclusive lock is
acquired the timestamp should be incremented.
1999-03-06 07:11:33 +00:00
Alan Cox
e5f251d2d3 Remove the last of the share map code: struct vm_map::is_main_map.
Reviewed by:	Matthew Dillon <dillon@apollo.backplane.com>
1999-03-02 05:43:18 +00:00
Luoqi Chen
b1028ad122 Hide access to vmspace:vm_pmap with inline function vmspace_pmap(). This
is the preparation step for moving pmap storage out of vmspace proper.

Reviewed by:	Alan Cox	<alc@cs.rice.edu>
		Matthew Dillion	<dillon@apollo.backplane.com>
1999-02-19 14:25:37 +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
Julian Elischer
2907af2a96 Mostly remove the VM_STACK OPTION.
This changes the definitions of a few items so that structures are the
same whether or not the option itself is enabled. This allows
people to enable and disable the option without recompilng the world.

As the author says:

|I ran into a problem pulling out the VM_STACK option.  I was aware of this
|when I first did the work, but then forgot about it.  The VM_STACK stuff
|has some code changes in the i386 branch.  There need to be corresponding
|changes in the alpha branch before it can come out completely.

what is done:
|
|1) Pull the VM_STACK option out of the header files it appears in.  This
|really shouldn't affect anything that executes with or without the rest
|of the VM_STACK patches.  The vm_map_entry will then always have one
|extra element (avail_ssize).  It just won't be used if the VM_STACK
|option is not turned on.
|
|I've also pulled the option out of vm_map.c.  This shouldn't harm anything,
|since the routines that are enabled as a result are not called unless
|the VM_STACK option is enabled elsewhere.
|
|2) Add what appears to be appropriate code the the alpha branch, still
|protected behind the VM_STACK switch.  I don't have an alpha machine,
|so we would need to get some testers with alpha machines to try it out.
|
|Once there is some testing, we can consider making the change permanent
|for both i386 and alpha.
|
[..]
|
|Once the alpha code is adequately tested, we can pull VM_STACK out
|everywhere.
|

Submitted by:	"Richard Seaman, Jr." <dick@tar.com>
1999-01-26 02:49:52 +00:00
Julian Elischer
2267af789e Add (but don't activate) code for a special VM option to make
downward growing stacks more general.
Add (but don't activate) code to use the new stack facility
when running threads, (specifically the linux threads support).
This allows people to use both linux compiled linuxthreads, and also the
native FreeBSD linux-threads port.

The code is conditional on VM_STACK. Not using this will
produce the old heavily tested system.

Submitted by: Richard Seaman <dick@tar.com>
1999-01-06 23:05:42 +00:00
John Dyson
2d8acc0f4a VM level code cleanups.
1)	Start using TSM.
	Struct procs continue to point to upages structure, after being freed.
	Struct vmspace continues to point to pte object and kva space for kstack.
	u_map is now superfluous.
2)	vm_map's don't need to be reference counted.  They always exist either
	in the kernel or in a vmspace.  The vmspaces are managed by reference
	counts.
3)	Remove the "wired" vm_map nonsense.
4)	No need to keep a cache of kernel stack kva's.
5)	Get rid of strange looking ++var, and change to var++.
6)	Change more data structures to use our "zone" allocator.  Added
	struct proc, struct vmspace and struct vnode.  This saves a significant
	amount of kva space and physical memory.  Additionally, this enables
	TSM for the zone managed memory.
7)	Keep ioopt disabled for now.
8)	Remove the now bogus "single use" map concept.
9)	Use generation counts or id's for data structures residing in TSM, where
	it allows us to avoid unneeded restart overhead during traversals, where
	blocking might occur.
10)	Account better for memory deficits, so the pageout daemon will be able
	to make enough memory available (experimental.)
11)	Fix some vnode locking problems. (From Tor, I think.)
12)	Add a check in ufs_lookup, to avoid lots of unneeded calls to bcmp.
	(experimental.)
13)	Significantly shrink, cleanup, and make slightly faster the vm_fault.c
	code.  Use generation counts, get rid of unneded collpase operations,
	and clean up the cluster code.
14)	Make vm_zone more suitable for TSM.

This commit is partially as a result of discussions and contributions from
other people, including DG, Tor Egge, PHK, and probably others that I
have forgotten to attribute (so let me know, if I forgot.)

This is not the infamous, final cleanup of the vnode stuff, but a necessary
step.  Vnode mgmt should be correct, but things might still change, and
there is still some missing stuff (like ioopt, and physical backing of
non-merged cache files, debugging of layering concepts.)
1998-01-22 17:30:44 +00:00
John Dyson
4722175765 Tie up some loose ends in vnode/object management. Remove an unneeded
config option in pmap.  Fix a problem with faulting in pages.  Clean-up
some loose ends in swap pager memory management.

The system should be much more stable, but all subtile bugs aren't fixed yet.
1998-01-17 09:17:02 +00:00
John Dyson
95e5e988e0 Make our v_usecount vnode reference count work identically to the
original BSD code.  The association between the vnode and the vm_object
no longer includes reference counts.  The major difference is that
vm_object's are no longer freed gratuitiously from the vnode, and so
once an object is created for the vnode, it will last as long as the
vnode does.

When a vnode object reference count is incremented, then the underlying
vnode reference count is incremented also.  The two "objects" are now
more intimately related, and so the interactions are now much less
complex.

When vnodes are now normally placed onto the free queue with an object still
attached.  The rundown of the object happens at vnode rundown time, and
happens with exactly the same filesystem semantics of the original VFS
code.  There is absolutely no need for vnode_pager_uncache and other
travesties like that anymore.

A side-effect of these changes is that SMP locking should be much simpler,
the I/O copyin/copyout optimizations work, NFS should be more ponderable,
and further work on layered filesystems should be less frustrating, because
of the totally coherent management of the vnode objects and vnodes.

Please be careful with your system while running this code, but I would
greatly appreciate feedback as soon a reasonably possible.
1998-01-06 05:26:17 +00:00
John Dyson
1efb74fbcc Some performance improvements, and code cleanups (including changing our
expensive OFF_TO_IDX to btoc whenever possible.)
1997-12-19 09:03:37 +00:00
John Dyson
03e9c6c101 Fix kern_lock so that it will work. Additionally, clean-up some of the
VM systems usage of the kernel lock (lockmgr) code.  This is a first
pass implementation, and is expected to evolve as needed.  The API
for the lock manager code has not changed, but the underlying implementation
has changed significantly.  This change should not materially affect
our current SMP or UP code without non-standard parameters being used.
1997-08-18 02:06:35 +00:00
John Dyson
3075778b63 Get rid of the ad-hoc memory allocator for vm_map_entries, in lieu of
a simple, clean zone type allocator.  This new allocator will also be
used for machine dependent pmap PV entries.
1997-08-05 00:02:08 +00:00
Peter Wemm
a2a1c95c10 The biggie: Get rid of the UPAGES from the top of the per-process address
space. (!)

Have each process use the kernel stack and pcb in the kvm space.  Since
the stacks are at a different address, we cannot copy the stack at fork()
and allow the child to return up through the function call tree to return
to user mode - create a new execution context and have the new process
begin executing from cpu_switch() and go to user mode directly.
In theory this should speed up fork a bit.

Context switch the tss_esp0 pointer in the common tss.  This is a lot
simpler since than swithching the gdt[GPROC0_SEL].sd.sd_base pointer
to each process's tss since the esp0 pointer is a 32 bit pointer, and the
sd_base setting is split into three different bit sections at non-aligned
boundaries and requires a lot of twiddling to reset.

The 8K of memory at the top of the process space is now empty, and unmapped
(and unmappable, it's higher than VM_MAXUSER_ADDRESS).

Simplity the pmap code to manage process contexts, we no longer have to
double map the UPAGES, this simplifies and should measuably speed up fork().

The following parts came from John Dyson:

Set PG_G on the UPAGES that are now in kernel context, and invalidate
them when swapping them out.

Move the upages object (upobj) from the vmspace to the proc structure.

Now that the UPAGES (pcb and kernel stack) are out of user space, make
rfork(..RFMEM..) do what was intended by sharing the vmspace
entirely via reference counting rather than simply inheriting the mappings.
1997-04-07 07:16:06 +00:00
John Dyson
a04c970a7a Fix the gdb executable modify problem. Thanks to the detective work
by Alan Cox <alc@cs.rice.edu>, and his description of the problem.

The bug was primarily in procfs_mem, but the mistake likely happened
due to the lack of vm system support for the operation.  I added
better support for selective marking of page dirty flags so that
vm_map_pageable(wiring) will not cause this problem again.

The code in procfs_mem is now less bogus (but maybe still a little
so.)
1997-04-06 02:29:45 +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
697030ed3d Removed vestiges of Mach lock types.
vm_map.h:
Removed #include of <sys/proc.h>.  curproc is only used in some macros
and users of the macros already include <sys/proc.h>.
1997-02-18 14:07:03 +00:00
John Dyson
996c772f58 This is the kernel Lite/2 commit. There are some requisite userland
changes, so don't expect to be able to run the kernel as-is (very well)
without the appropriate Lite/2 userland changes.

The system boots and can mount UFS filesystems.

Untested: ext2fs, msdosfs, NFS
Known problems: Incorrect Berkeley ID strings in some files.
		Mount_std mounts will not work until the getfsent
		library routine is changed.

Reviewed by:	various people
Submitted by:	Jeffery Hsu <hsu@freebsd.org>
1997-02-10 02:22:35 +00:00
John Dyson
afa07f7e83 Change the map entry flags from bitfields to bitmasks. Allows
for some code simplification.
1997-01-16 04:16:22 +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
b7b2aac2b6 Eliminate the redundancy due to the similarity between the routines
vm_map_simplify and vm_map_simplify_entry.  Make vm_map_simplify_entry
handle wired maps so that we can get rid of vm_map_simplify.  Modify
the callers of vm_map_simplify to properly use vm_map_simplify_entry.
Submitted by:	Alan Cox <alc@cs.rice.edu>
1996-12-28 23:07:49 +00:00
John Dyson
7aaaa4fd5d Implement closer-to POSIX mlock semantics. The major difference is
that we do allow mlock to span unallocated regions (of course, not
mlocking them.)  We also allow mlocking of RO regions (which the old
code couldn't.)  The restriction there is that once a RO region is
wired (mlocked), it cannot be debugged (or EVER written to.)

Under normal usage, the new mlock code will be a significant improvement
over our old stuff.
1996-12-14 17:54:17 +00:00
John Dyson
cdc2c29161 Make vm_map_insert much more intelligent in the MAP_NOFAULT case so
that map entries are coalesced when appropriate.  Also, conditionalize
some code that is currently not used in vm_map_insert.  This mod
has been added to eliminate unnecessary map entries in buffer map.

Additionally, there were some cases where map coalescing could be done
when it shouldn't.  That problem has been resolved.
1996-12-07 00:03:43 +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
67bf686897 Backed out the recent changes/enhancements to the VM code. The
problem with the 'shell scripts' was found, but there was a 'strange'
problem found with a 486 laptop that we could not find.  This commit
backs the code back to 25-jul, and will be re-entered after the snapshot
in smaller (more easily tested) chunks.
1996-07-30 03:08:57 +00:00
John Dyson
4f4d35edf0 This commit is meant to solve a couple of VM system problems or
performance issues.

	1) The pmap module has had too many inlines, and so the
	   object file is simply bigger than it needs to be.
	   Some common code is also merged into subroutines.
	2) Removal of some *evil* PHYS_TO_VM_PAGE macro calls.
	   Unfortunately, a few have needed to be added also.
	   The removal caused the need for more vm_page_lookups.
	   I added lookup hints to minimize the need for the
	   page table lookup operations.
	3) Removal of some bogus performance improvements, that
	   mostly made the code more complex (tracking individual
	   page table page updates unnecessarily).  Those improvements
	   actually hurt 386 processors perf (not that people who
	   worry about perf use 386 processors anymore :-)).
	4) Changed pv queue manipulations/structures to be TAILQ's.
	5) The pv queue code has had some performance problems since
	   day one.  Some significant scalability issues are resolved
	   by threading the pv entries from the pmap AND the physical
	   address instead of just the physical address.  This makes
	   certain pmap operations run much faster.  This does
	   not affect most micro-benchmarks, but should help loaded system
	   performance *significantly*.  DG helped and came up with most
	   of the solution for this one.
	6) Most if not all pmap bit operations follow the pattern:
		pmap_test_bit();
		pmap_clear_bit();
	   That made for twice the necessary pv list traversal.   The
	   pmap interface now supports only pmap_tc_bit type operations:
	   pmap_[test/clear]_modified, pmap_[test/clear]_referenced.
	   Additionally, the modified routine now takes a vm_page_t arg
	   instead of a phys address.  This eliminates a PHYS_TO_VM_PAGE
	   operation.
	7) Several rewrites of routines that contain redundant code to
	   use common routines, so that there is a greater likelihood of
	   keeping the cache footprint smaller.
1996-07-27 03:24:10 +00:00
John Dyson
867a482d66 Initial support for mincore and madvise. Both are almost fully
supported, except madvise does not page in with MADV_WILLNEED, and
MADV_DONTNEED doesn't force dirty pages out.
1996-05-19 07:36:50 +00:00
Mike Pritchard
6c5e9bbdf5 Fix a bunch of spelling errors in the comment fields of
a bunch of system include files.
1996-01-30 23:02:38 +00:00