Commit Graph

70 Commits

Author SHA1 Message Date
imp
f0bf889d0d /* -> /*- for license, minor formatting changes 2005-01-07 02:29:27 +00:00
alc
c380417937 - pmap_kenter_temporary() is unused by machine-independent code. Therefore,
move its declaration to the machine-dependent header file on those
   machines that use it.  In principle, only i386 should have it.
   Alpha and AMD64 should use their direct virtual-to-physical mapping.
 - Remove pmap_kenter_temporary() from ia64.  It is unused.  Approved
   by: marcel@
2004-04-10 22:41:46 +00:00
imp
04c9462c02 Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core
2004-04-06 20:15:37 +00:00
alc
19e5eda309 Remove unused arguments from pmap_init(). 2004-04-05 00:37:50 +00:00
alc
f13324f65b Retire pmap_pinit2(). Alpha was the last platform that used it. However,
ever since alpha/alpha/pmap.c revision 1.81 introduced the list allpmaps,
there has been no reason for having this function on Alpha.  Briefly,
when pmap_growkernel() relied upon the list of all processes to find and
update the various pmaps to reflect a growth in the kernel's valid
address space, pmap_init2() served to avoid a race between pmap
initialization and pmap_growkernel().  Specifically, pmap_pinit2() was
responsible for initializing the kernel portions of the pmap and
pmap_pinit2() was called after the process structure contained a pointer
to the new pmap for use by pmap_growkernel().  Thus, an update to the
kernel's address space might be applied to the new pmap unnecessarily,
but an update would never be lost.
2004-03-07 21:06:48 +00:00
bms
d8d01a1fa7 Move pmap_resident_count() from the MD pmap.h to the MI pmap.h.
Add a definition of pmap_wired_count().
Add a definition of vmspace_wired_count().

Reviewed by:	truckman
Discussed with:	peter
2003-10-06 01:47:12 +00:00
alc
b1691aebe4 Migrate pmap_prefault() into the machine-independent virtual memory layer.
A small helper function pmap_is_prefaultable() is added.  This function
encapsulate the few lines of pmap_prefault() that actually vary from
machine to machine.  Note: pmap_is_prefaultable() and pmap_mincore() have
much in common.  Going forward, it's worth considering their merger.
2003-10-03 22:46:53 +00:00
alc
76fcb264a0 Add a new parameter to pmap_extract_and_hold() that is needed to eliminate
Giant from vmapbuf().

Idea from:	tegge
2003-09-12 07:07:49 +00:00
alc
a81d9ad0b9 Introduce a new pmap function, pmap_extract_and_hold(). This function
atomically extracts and holds the physical page that is associated with the
given pmap and virtual address.  Such a function is needed to make the
memory mapping optimizations used by, for example, pipes and raw disk I/O
MP-safe.

Reviewed by:	tegge
2003-09-08 02:45:03 +00:00
alc
0699f7e17f Background: pmap_object_init_pt() premaps the pages of a object in
order to avoid the overhead of later page faults.  In general, it
implements two cases: one for vnode-backed objects and one for
device-backed objects.  Only the device-backed case is really
machine-dependent, belonging in the pmap.

This commit moves the vnode-backed case into the (relatively) new
function vm_map_pmap_enter().  On amd64 and i386, this commit only
amounts to code rearrangement.  On alpha and ia64, the new machine
independent (MI) implementation of the vnode case is smaller and more
efficient than their pmap-based implementations.  (The MI
implementation takes advantage of the fact that objects in -CURRENT
are ordered collections of pages.)  On sparc64, pmap_object_init_pt()
hadn't (yet) been implemented.
2003-07-03 20:18:02 +00:00
alc
44509f207f - Export pmap_enter_quick() to the MI VM. This will permit the
implementation of a largely MI pmap_object_init_pt() for vnode-backed
   objects.  pmap_enter_quick() is implemented via pmap_enter() on sparc64
   and powerpc.
 - Correct a mismatch between pmap_object_init_pt()'s prototype and its
   various implementations.  (I plan to keep pmap_object_init_pt() as
   the MD hook for device-backed objects on i386 and amd64.)
 - Correct an error in ia64's pmap_enter_quick() and adjust its interface
   to match the other versions.  Discussed with: marcel
2003-06-29 21:20:04 +00:00
alc
83f108b04d Migrate the thread stack management functions from the machine-dependent
to the machine-independent parts of the VM.  At the same time, this
introduces vm object locking for the non-i386 platforms.

Two details:

1. KSTACK_GUARD has been removed in favor of KSTACK_GUARD_PAGES.  The
different machine-dependent implementations used various combinations
of KSTACK_GUARD and KSTACK_GUARD_PAGES.  To disable guard page, set
KSTACK_GUARD_PAGES to 0.

2. Remove the (unnecessary) clearing of PG_ZERO in vm_thread_new.  In
5.x, (but not 4.x,) PG_ZERO can only be set if VM_ALLOC_ZERO is passed
to vm_page_alloc() or vm_page_grab().
2003-06-14 23:23:55 +00:00
alc
d20c30720b Move the *_new_altkstack() and *_dispose_altkstack() functions out of the
various pmap implementations into the machine-independent vm.  They were
all identical.
2003-06-14 06:20:25 +00:00
jhb
526c3912c0 - Kill the pv_flags member of the alpha mdpage since it stop being used
in rev 1.61 of pmap.c.
- Now that pmap_page_is_free() is empty and since it is just a hack for
  the Alpha pmap, remove it.
2003-04-10 18:42:06 +00:00
jake
783ae539c3 - Add vm_paddr_t, a physical address type. This is required for systems
where physical addresses larger than virtual addresses, such as i386s
  with PAE.
- Use this to represent physical addresses in the MI vm system and in the
  i386 pmap code.  This also changes the paddr parameter to d_mmap_t.
- Fix printf formats to handle physical addresses >4G in the i386 memory
  detection code, and due to kvtop returning vm_paddr_t instead of u_long.

Note that this is a name change only; vm_paddr_t is still the same as
vm_offset_t on all currently supported platforms.

Sponsored by:	DARPA, Network Associates Laboratories
Discussed with:	re, phk (cdevsw change)
2003-03-25 00:07:06 +00:00
jake
c1838df603 Made the prototypes for pmap_kenter and pmap_kremove MD. These functions
are machine dependent because they are not required to update the tlb when
mappings are added or removed, and doing so is machine dependent.
In addition, an implementation may require that pages mapped with pmap_kenter
have a backing vm_page_t, which is not necessarily true of all physical
pages, and so may choose to pass the vm_page_t to pmap_kenter instead of the
physical address in order to make this requirement clear.
2003-03-16 04:16:03 +00:00
mux
541937cf73 Cleanup of the d_mmap_t interface.
- Get rid of the useless atop() / pmap_phys_address() detour.  The
  device mmap handlers must now give back the physical address
  without atop()'ing it.
- Don't borrow the physical address of the mapping in the returned
  int.  Now we properly pass a vm_offset_t * and expect it to be
  filled by the mmap handler when the mapping was successful.  The
  mmap handler must now return 0 when successful, any other value
  is considered as an error.  Previously, returning -1 was the only
  way to fail.  This change thus accidentally fixes some devices
  which were bogusly returning errno constants which would have been
  considered as addresses by the device pager.
- Garbage collect the poorly named pmap_phys_address() now that it's
  no longer used.
- Convert all the d_mmap_t consumers to the new API.

I'm still not sure wheter we need a __FreeBSD_version bump for this,
since and we didn't guarantee API/ABI stability until 5.1-RELEASE.

Discussed with:		alc, phk, jake
Reviewed by:		peter
Compile-tested on:	LINT (i386), GENERIC (alpha and sparc64)
Runtime-tested on:	i386
2003-02-25 03:21:22 +00:00
alc
11334c6aeb Move kernel_vm_end's declaration to pmap.h; add a comment regarding the
synchronization of access to kernel_vm_end.
2003-02-15 19:38:23 +00:00
alc
c02d224c79 Move pmap_collect() out of the machine-dependent code, rename it
to reflect its new location, and add page queue and flag locking.

Notes: (1) alpha, i386, and ia64 had identical implementations
of pmap_collect() in terms of machine-independent interfaces;
(2) sparc64 doesn't require it; (3) powerpc had it as a TODO.
2002-11-13 05:39:58 +00:00
alc
78766a7b7a - Clear the page's PG_WRITEABLE flag in the i386's pmap_changebit()
if we're removing write access from the page's PTEs.
 - Export pmap_remove_all() on alpha, i386, and ia64.  (It's already
   exported on sparc64.)
2002-11-11 05:17:34 +00:00
scottl
3a150bca9c Some kernel threads try to do significant work, and the default KSTACK_PAGES
doesn't give them enough stack to do much before blowing away the pcb.
This adds MI and MD code to allow the allocation of an alternate kstack
who's size can be speficied when calling kthread_create.  Passing the
value 0 prevents the alternate kstack from being created.  Note that the
ia64 MD code is missing for now, and PowerPC was only partially written
due to the pmap.c being incomplete there.
Though this patch does not modify anything to make use of the alternate
kstack, acpi and usb are good candidates.

Reviewed by:	jake, peter, jhb
2002-10-02 07:44:29 +00:00
alc
d5f256dae2 o Retire pmap_pageable(). It's an advisory routine that none
of our platforms implements.
2002-08-25 04:20:05 +00:00
peter
62e40d1277 Add a special page zero entry point intended to be called via the single
threaded VM pagezero kthread outside of Giant.  For some platforms, this
is really easy since it can just use the direct mapped region.  For others,
IPI sending is involved or there are other issues, so grab Giant when
needed.

We still have preemption issues to deal with, but Alan Cox has an
interesting suggestion on how to minimize the problem on x86.

Use Luigi's hack for preserving the (lack of) priority.

Turn the idle zeroing back on since it can now actually do something useful
outside of Giant in many cases.
2002-07-08 04:24:26 +00:00
peter
b73c441dad Collect all the (now equivalent) pmap_new_proc/pmap_dispose_proc/
pmap_swapin_proc/pmap_swapout_proc functions from the MD pmap code
and use a single equivalent MI version.  There are other cleanups
needed still.

While here, use the UMA zone hooks to keep a cache of preinitialized
proc structures handy, just like the thread system does.  This eliminates
one dependency on 'struct proc' being persistent even after being freed.
There are some comments about things that can be factored out into
ctor/dtor functions if it is worth it.  For now they are mostly just
doing statistics to get a feel of how it is working.
2002-07-07 23:05:27 +00:00
peter
c0e3147cc6 Tidy up some loose ends.
i386/ia64/alpha - catch up to sparc64/ppc:
- replace pmap_kernel() with refs to kernel_pmap
- change kernel_pmap pointer to (&kernel_pmap_store)
  (this is a speedup since ld can set these at compile/link time)
all platforms (as suggested by jake):
- gc unused pmap_reference
- gc unused pmap_destroy
- gc unused struct pmap.pm_count
(we never used pm_count - we track address space sharing at the vmspace)
2002-04-29 07:43:16 +00:00
peter
3d8c7d4cab Pass vm_page_t instead of physical addresses to pmap_zero_page[_area]()
and pmap_copy_page().  This gets rid of a couple more physical addresses
in upper layers, with the eventual aim of supporting PAE and dealing with
the physical addressing mostly within pmap.  (We will need either 64 bit
physical addresses or page indexes, possibly both depending on the
circumstances.  Leaving this to pmap itself gives more flexibilitly.)

Reviewed by:	jake
Tested on:	i386, ia64 and (I believe) sparc64. (my alpha was hosed)
2002-04-15 16:00:03 +00:00
alfred
1446d09429 Remove __P. 2002-03-19 22:20:14 +00:00
eivind
0799ec54b1 - Remove a number of extra newlines that do not belong here according to
style(9)
- Minor space adjustment in cases where we have "( ", " )", if(), return(),
  while(), for(), etc.
- Add /* SYMBOL */ after a few #endifs.

Reviewed by:	alc
2002-03-10 21:52:48 +00:00
silby
230f96f3ce Fix a horribly suboptimal algorithm in the vm_daemon.
In order to determine what to page out, the vm_daemon checks
reference bits on all pages belonging to all processes.  Unfortunately,
the algorithm used reacted badly with shared pages; each shared page
would be checked once per process sharing it; this caused an O(N^2)
growth of tlb invalidations.  The algorithm has been changed so that
each page will be checked only 16 times.

Prior to this change, a fork/sleepbomb of 1300 processes could cause
the vm_daemon to take over 60 seconds to complete, effectively
freezing the system for that time period.  With this change
in place, the vm_daemon completes in less than a second.  Any system
with hundreds of processes sharing pages should benefit from this change.

Note that the vm_daemon is only run when the system is under extreme
memory pressure.  It is likely that many people with loaded systems saw
no symptoms of this problem until they reached the point where swapping
began.

Special thanks go to dillon, peter, and Chuck Cranor, who helped me
get up to speed with vm internals.

PR:		33542, 20393
Reviewed by:	dillon
MFC after:	1 week
2002-02-27 18:03:02 +00:00
julian
5596676e6c 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
jhb
1de39ad1a0 Unrevert the pmap_map() changes. They weren't broken on x86.
Sense beaten into me by:	peter
2001-03-07 05:29:21 +00:00
jhb
74a74a3282 Back out the pmap_map() change for now, it isn't completely stable on the
i386.
2001-03-07 01:04:17 +00:00
jhb
a710dd7194 - Rework pmap_map() to take advantage of direct-mapped segments on
supported architectures such as the alpha.  This allows us to save
  on kernel virtual address space, TLB entries, and (on the ia64) VHPT
  entries.  pmap_map() now modifies the passed in virtual address on
  architectures that do not support direct-mapped segments to point to
  the next available virtual address.  It also returns the actual
  address that the request was mapped to.
- On the IA64 don't use a special zone of PV entries needed for early
  calls to pmap_kenter() during pmap_init().  This gets us in trouble
  because we end up trying to use the zone allocator before it is
  initialized.  Instead, with the pmap_map() change, the number of needed
  PV entries is small enough that we can get by with a static pool that is
  used until pmap_init() is complete.

Submitted by:		dfr
Debugging help:		peter
Tested by:		me
2001-03-06 06:06:42 +00:00
ps
c71ac689e0 Implement write combining for crashdumps. This is useful when
write caching is disabled on both SCSI and IDE disks where large
memory dumps could take up to an hour to complete.

Taking an i386 scsi based system with 512MB of ram and timing (in
seconds) how long it took to complete a dump, the following results
were obtained:

Before:				After:
	WCE           TIME		WCE           TIME
	------------------		------------------
	1	141.820972		1	 15.600111
	0	797.265072		0	 65.480465

Obtained from:	Yahoo!
Reviewed by:	peter
2000-10-17 10:05:49 +00:00
dfr
14048face6 Brucify the pmap_enter_temporary() changes. 2000-05-29 19:21:01 +00:00
dfr
3d3263476e Add a new pmap entry point, pmap_enter_temporary() to be used during
dumps to create temporary page mappings. This replaces the use of CADDR1
which is fairly x86 specific.

Reviewed by: dillon
2000-05-28 15:49:55 +00:00
peter
ee5cd6988f 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
peter
d53e4c1d80 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
peter
3b842d34e8 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
alc
279eafd09f Fix the following problem:
When creating new processes (or performing exec), the new page
directory is initialized too early.  The kernel might grow before
p_vmspace is initialized for the new process.  Since pmap_growkernel
doesn't yet know about the new page directory, it isn't updated, and
subsequent use causes a failure.

The fix is (1) to clear p_vmspace early, to stop pmap_growkernel
from stomping on memory, and (2) to defer part of the initialization
of new page directories until p_vmspace is initialized.

PR:		kern/12378
Submitted by:	tegge
Reviewed by:	dfr
1999-07-21 18:02:27 +00:00
dt
9efe75f7a6 Make pmap_collect() an official pmap interface. 1999-04-23 20:29:58 +00:00
julian
0ed09d2ad5 Catch a case spotted by Tor where files mmapped could leave garbage in the
unallocated parts of the last page when the file ended on a frag
but not a page boundary.
Delimitted by tags PRE_MATT_MMAP_EOF and POST_MATT_MMAP_EOF,
in files alpha/alpha/pmap.c i386/i386/pmap.c nfs/nfs_bio.c vm/pmap.h
    vm/vm_page.c vm/vm_page.h vm/vnode_pager.c miscfs/specfs/spec_vnops.c
    ufs/ufs/ufs_readwrite.c kern/vfs_bio.c

Submitted by: Matt Dillon <dillon@freebsd.org>
Reviewed by: Alan Cox <alc@freebsd.org>
1999-04-05 19:38:30 +00:00
dfr
9c96ae361d Notify pmap when a page is freed on the alpha to allow it to clean up
its emulated modified/referenced bits.
1998-07-26 18:15:20 +00:00
bde
2adc6309fe Forward declare more structs that are used in prototypes here - don't
depend on <sys/types.h> forward declaring common ones.
1998-02-01 20:08:39 +00:00
dyson
197bd655c4 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
dyson
738872cad6 After one of my analysis passes to evaluate methods for SMP TLB mgmt, I
noticed some major enhancements available for UP situations.  The number
of UP TLB flushes is decreased much more than significantly with these
changes.  Since a TLB flush appears to cost minimally approx 80 cycles,
this is a "nice" enhancement, equiv to eliminating between 40 and 160
instructions per TLB flush.

Changes include making sure that kernel threads all use the same PTD,
and eliminate unneeded PTD switches at context switch time.
1997-12-14 02:11:23 +00:00
dyson
e150d815cc Fixed the commit botch that was causing crashes soon after system
startup.  Due to the error, the initialization of the zone for
pv_entries was missing.  The system should be usable again.
1997-08-05 23:03:24 +00:00
dyson
55205b3be5 Fix some bugs, document vm_zone better. Add copyright to vm_zone.h. Use
the new zone code in pmap.c so that we can get rid of the ugly ad-hoc
allocations in pmap.c.
1997-08-05 22:07:27 +00:00
dyson
96f688be11 Modify pmap to use our new memory allocator. Also, change the vm_map_entry
allocations to be interrupt safe.
1997-08-05 01:32:52 +00:00
dyson
b39089e3e9 Add support for 4MB pages. This includes the .text, .data, .data parts
of the kernel, and also most of the dynamic parts of the kernel.  Additionally,
4MB pages will be allocated for display buffers as appropriate (only.)

The 4MB support for SMP isn't complete, but doesn't interfere with operation
either.
1997-07-17 04:34:03 +00:00