Commit Graph

282 Commits

Author SHA1 Message Date
Alan Cox
1bb816d3d1 Restructure vm_page_select_cache() so that adding assertions is easy.
Some of the conditions that caused vm_page_select_cache() to deactivate a
page were wrong.  For example, deactivating an unmanaged or wired page is a
nop.  Thus, if vm_page_select_cache() had ever encountered an unmanaged or
wired page, it would have looped forever.  Now, we assert that the page is
neither unmanaged nor wired.
2004-05-12 04:27:18 +00:00
Alan Cox
3f39cca96b Cache queue pages are not mapped. Thus, the pmap_remove_all() by
vm_page_alloc() is unnecessary.
2004-05-09 01:00:15 +00:00
Alan Cox
2ec91846fd Update the comment describing vm_page_grab() to reflect the previous
revision and correct some of its style errors.
2004-04-24 21:36:23 +00:00
Alan Cox
7ef6ba5d27 Push down the responsibility for zeroing a physical page from the
caller to vm_page_grab().  Although this gives VM_ALLOC_ZERO a
different meaning for vm_page_grab() than for vm_page_alloc(), I feel
such change is necessary to accomplish other goals.  Specifically, I
want to make the PG_ZERO flag immutable between the time it is
allocated by vm_page_alloc() and freed by vm_page_free() or
vm_page_free_zero() to avoid locking overheads.  Once we gave up on
the ability to automatically recognize a zeroed page upon entry to
vm_page_free(), the ability to mutate the PG_ZERO flag became useless.
Instead, I would like to say that "Once a page becomes valid, its
PG_ZERO flag must be ignored."
2004-04-24 20:53:55 +00:00
Warner Losh
05eb3785e7 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
Alan Cox
889eb0fc62 Eliminate unused arguments from vm_page_startup(). 2004-04-04 23:33:36 +00:00
Alan Cox
ca3b447732 Modify contigmalloc1() so that the free page queues lock is not held when
vm_page_free() is called.  The problem with holding this lock is that it is
a spin lock and vm_page_free() may attempt the acquisition of a different
default-type lock.
2004-03-02 08:25:58 +00:00
Alan Cox
0f75a97722 - Correct a long-standing race condition in vm_page_try_to_free() that
could result in a dirty page being unintentionally freed.
 - Simplify the dirty page check in vm_page_dontneed().

Reviewed by:	tegge
MFC after:	7 days
2004-02-19 07:43:55 +00:00
Alan Cox
84d98bf699 - Correct a long-standing race condition in vm_page_try_to_cache() that
could result in a panic "vm_page_cache: caching a dirty page, ...":
   Access to the page must be restricted or removed before calling
   vm_page_cache().  This race condition is identical in nature to that
   which was addressed by vm_pageout.c's revision 1.251.
 - Simplify the code surrounding the fix to this same race condition
   in vm_pageout.c's revision 1.251.  There should be no behavioral
   change.  Reviewed by: tegge

MFC after:	7 days
2004-02-14 08:54:37 +00:00
Alan Cox
65bae14d77 - Enable recursive acquisition of the mutex synchronizing access to the
free pages queue.  This is presently needed by contigmalloc1().
 - Move a sanity check against attempted double allocation of two pages
   to the same vm object offset from vm_page_alloc() to vm_page_insert().
   This provides better protection because double allocation could occur
   through a direct call to vm_page_insert(), such as that by
   vm_page_rename().
 - Modify contigmalloc1() to hold the mutex synchronizing access to the
   free pages queue while it scans vm_page_array in search of free pages.
 - Correct a potential leak of pages by contigmalloc1() that I introduced
   in revision 1.20: We must convert all cache queue pages to free pages
   before we begin removing free pages from the free queue.  Otherwise,
   if we have to restart the scan because we are unable to acquire the
   vm object lock that is necessary to convert a cache queue page to a
   free page, we leak those free pages already removed from the free queue.
2004-01-08 20:48:26 +00:00
Alan Cox
4804edb44f In vm_page_lookup() check the root of the vm object's splay tree for the
desired page before calling vm_page_splay().
2003-12-31 19:02:01 +00:00
Alan Cox
bcdaad7fe7 Simplify vm_page_grab(): Don't bother with the generation check. If the
vm object hasn't changed, the desired page will be at or near the root
of the vm object's splay tree, making vm_page_lookup() cheap.  (The only
lock required for vm_page_lookup() is already held.)  If, however, the
vm object has changed and retry was requested, eliminating the generation
check also eliminates a pointless acquisition and release of the page
queues lock.
2003-12-31 01:44:45 +00:00
Alan Cox
9582cd94cb - Create an unmapped guard page to trap access to vm_page_array[-1].
This guard page would have trapped the problems with the MFC of the PAE
   support to RELENG_4 at an earlier point in the sequence of events.

Submitted by:	tegge
2003-12-22 02:04:08 +00:00
Alan Cox
de33beddd5 - Additional vm object locking in vm_object_split()
- New vm object locking assertions in vm_page_insert() and
   vm_object_set_writeable_dirty()
2003-11-01 04:54:23 +00:00
Alan Cox
ab42316c2f - Retire vm_pageout_page_free(). Instead, use vm_page_select_cache() from
vm_pageout_scan().  Rationale: I don't like leaving a busy page in the
   cache queue with neither the vm object nor the vm page queues lock held.
 - Assert that the page is active in vm_pageout_page_stats().
2003-10-22 18:41:32 +00:00
Alan Cox
0d42c05ff4 - Assert that the containing vm object is locked in
vm_page_set_validclean().  (This function reads and modifies the
   vm page's valid field, which is synchronized by the lock on the
   containing vm object.)
2003-10-21 19:36:51 +00:00
Alan Cox
fee181a696 - Remove some long unused code. 2003-10-20 18:57:01 +00:00
Alan Cox
669890eaeb Retire vm_page_copy(). Its reason for being ended when peter@ modified
pmap_copy_page() et al. to accept a vm_page_t rather than a physical
address.  Also, this change will facilitate locking access to the vm page's
valid field.
2003-10-08 05:35:12 +00:00
Alan Cox
5a3970febf Assert that the containing vm object's lock is held in
vm_page_set_invalid().
2003-10-05 06:58:07 +00:00
Alan Cox
874f526de6 Assert that the containing vm object's lock is held in
vm_page_zero_invalid().
2003-10-04 21:56:27 +00:00
Alan Cox
bf0da100d6 - Extend the scope the vm object lock to cover calls to
vm_page_is_valid().
 - Assert that the lock on the containing vm object is held in
   vm_page_is_valid().
2003-10-04 19:23:29 +00:00
Alan Cox
50028aa7d2 In vm_page_remove(), assert that the vm object is locked, unless an Alpha.
(The Alpha still requires updates to its pmap.)
2003-09-28 04:50:48 +00:00
Alan Cox
95aad59a53 Initialize the page's pindex field even for VM_ALLOC_NOOBJ allocations.
(This field is useful for implementing sanity checks even if the page does
not belong to an object.)
2003-09-22 00:56:13 +00:00
Alan Cox
2370c6d40c Recent pmap changes permit the use of a more precise locking assertion
in vm_page_lookup().
2003-08-28 23:23:04 +00:00
Alan Cox
529e15ed69 Held pages, just like wired pages, should not be added to the cache queues.
Submitted by:	tegge
2003-08-23 20:29:29 +00:00
Alan Cox
b7ad744dc5 Hold the page queues lock when performing vm_page_clear_dirty() and
vm_page_set_invalid().
2003-08-23 18:11:53 +00:00
Alan Cox
0f132ba697 Assert that the vm object's lock is held on entry to vm_page_grab(); remove
code from this function that was needed when vm object locking was
incomplete.
2003-08-21 20:59:07 +00:00
Alan Cox
891c1d4bd3 Assert that the vm object lock is held in vm_page_alloc(). 2003-08-20 20:24:29 +00:00
Alan Cox
c53e8c5654 Modify vm_page_alloc() and vm_page_select_cache() to allow the page that
is returned by vm_page_select_cache() to belong to the object that is
already locked by the caller to vm_page_alloc().
2003-07-01 07:33:41 +00:00
Alan Cox
baaaadf125 - Use an int rather than a vm_pindex_t to represent the desired page
color in vm_page_alloc().  (This also has small performance benefits.)
 - Eliminate vm_page_select_free(); vm_page_alloc() might as well
   call vm_pageq_find() directly.
2003-06-28 07:58:10 +00:00
Alan Cox
9f2b1758c3 vm_page_select_cache() enforces a number of conditions on the returned
page.  Add the ability to lock the containing object to those conditions.
2003-06-26 15:44:03 +00:00
Alan Cox
f29ba63ec9 Maintain a lock on the vm object of interest throughout vm_fault(),
releasing the lock only if we are about to sleep (e.g., vm_pager_get_pages()
or vm_pager_has_pages()).  If we sleep, we have marked the vm object with
the paging-in-progress flag.
2003-06-22 21:35:41 +00:00
Alan Cox
37681d8642 Assert that the vm object is locked in vm_page_try_to_free(). 2003-06-19 01:50:14 +00:00
David E. O'Brien
874651b13c Use __FBSDID(). 2003-06-11 23:50:51 +00:00
Alan Cox
36d1fdf5a2 Teach vm_page_grab() how to handle the vm object's lock. 2003-06-07 23:22:04 +00:00
Alan Cox
5299887de5 - Relax the Giant required in vm_page_remove().
- Remove the Giant required from vm_page_free_toq().  (Any locking
   errors will be caught by vm_page_remove().)

This remedies a panic that occurred when kmem_malloc(NOWAIT) performed
without Giant failed to allocate the necessary pages.

Reported by:	phk
2003-04-25 06:35:05 +00:00
Alan Cox
2e9d00a15d Revision 1.246 should have also included
- Weaken the assertion in vm_page_insert() to require Giant only if the
   vm_object isn't locked.

Reported by:	 "Ilmar S. Habibulin" <ilmar@watson.org>
2003-04-22 14:26:02 +00:00
Alan Cox
03d4c1e644 Revision 1.52 of vm/uma_core.c has led to UMA's obj_alloc() being
called without Giant; and obj_alloc() in turn calls vm_page_alloc()
without Giant.  This causes an assertion failure in vm_page_alloc().
Fortunately, obj_alloc() is now MPSAFE.  So, we need only clean up
some assertions.

 - Weaken the assertion in vm_page_lookup() to require Giant only
   if the vm_object isn't locked.
 - Remove an assertion from vm_page_alloc() that duplicates a check
   performed in vm_page_lookup().

In collaboration with:	gallatin, jake, jeff
2003-04-22 05:36:14 +00:00
John Baldwin
d8fed0f0f2 - 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 Burkholder
227f9a1c58 - 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
Maxime Henrion
dab392a4d4 Remove an empty comment. 2003-03-19 00:34:43 +00:00
Jake Burkholder
9f77ba59c5 Subtract the memory that backs the vm_page structures from phys_avail
after mapping it.  This makes it possible to determine if a physical
page has a backing vm_page or not.
2003-03-17 03:16:00 +00:00
Alan Cox
1a1e9f41e5 Teach vm_page_sleep_if_busy() to release the vm_object lock before sleeping. 2003-03-01 19:16:32 +00:00
Alan Cox
3fa24ec9f1 In vm_page_dirty(), assert that the page is not in the free queue(s). 2003-02-24 17:30:45 +00:00
Alan Cox
e6f2748cbc - Convert the tsleep()s in vm_wait() and vm_waitpfault() to msleep()s
with the page queue lock.
 - Assert that the page queue lock is held in vm_page_free_wakeup().
2003-02-01 21:18:16 +00:00
Alan Cox
28ec30cd9f - Hold the page queues lock around vm_page_hold().
- Assert that the page queues lock rather than Giant is held in
   vm_page_hold().
2003-01-20 09:24:03 +00:00
Alan Cox
b0ef8c5fe4 - Update vm_pageout_deficit using atomic operations. It's a simple
counter outside the scope of existing locks.
 - Eliminate a redundant clearing of vm_pageout_deficit.
2003-01-14 06:57:03 +00:00
Alan Cox
a15700fe32 Make vm_page_alloc() return PG_ZERO only if VM_ALLOC_ZERO is specified.
The objective being to eliminate some cases of page queues locking.
(See, for example, vm/vm_fault.c revision 1.160.)

Reviewed by:	tegge

(Also, pointed out by tegge that I changed vm_fault.c before changing
vm_page.c.  Oops.)
2003-01-12 23:32:46 +00:00
Alan Cox
b5dc830507 In vm_page_alloc(), fuse two if statements that are conditioned on the same
expression.
2003-01-11 20:07:17 +00:00
Alan Cox
9a032278bd In vm_page_alloc(), honor VM_ALLOC_ZERO for system and interrupt class
requests when the number of free pages is below the reserved threshold.
Previously, VM_ALLOC_ZERO was only honored when the number of free pages
was above the reserved threshold.  Honoring it in all cases generally
makes sense, does no harm, and simplifies the code.
2003-01-08 19:58:42 +00:00