Commit Graph

152 Commits

Author SHA1 Message Date
Kip Macy
263811f724 exclude kmem_alloc'ed ARC data buffers from kernel minidumps on amd64
excluding other allocations including UMA now entails the addition of
a single flag to kmem_alloc or uma zone create

Reviewed by:	alc, avg
MFC after:	2 weeks
2012-01-27 20:18:31 +00:00
Alan Cox
703dec68bf Eliminate vestiges of page coloring in VM_ALLOC_NOOBJ calls to
vm_page_alloc().  While I'm here, for the sake of consistency, always
specify the allocation class, such as VM_ALLOC_NORMAL, as the first of
the flags.
2011-10-27 16:39:17 +00:00
Konstantin Belousov
d98d0ce27a - Move the PG_UNMANAGED flag from m->flags to m->oflags, renaming the flag
to VPO_UNMANAGED (and also making the flag protected by the vm object
  lock, instead of vm page queue lock).
- Mark the fake pages with both PG_FICTITIOUS (as it is now) and
  VPO_UNMANAGED. As a consequence, pmap code now can use use just
  VPO_UNMANAGED to decide whether the page is unmanaged.

Reviewed by:	alc
Tested by:	pho (x86, previous version), marius (sparc64),
    marcel (arm, ia64, powerpc), ray (mips)
Sponsored by:	The FreeBSD Foundation
Approved by:	re (bz)
2011-08-09 21:01:36 +00:00
Matthew D Fleming
cfb00e5aa7 Move the ZERO_REGION_SIZE to a machine-dependent file, as on many
architectures (i386, for example) the virtual memory space may be
constrained enough that 2MB is a large chunk.  Use 64K for arches
other than amd64 and ia64, with special handling for sparc64 due to
differing hardware.

Also commit the comment changes to kmem_init_zero_region() that I
missed due to not saving the file.  (Darn the unfamiliar development
environment).

Arch maintainers, please feel free to adjust ZERO_REGION_SIZE as you
see fit.

Requested by:	alc
MFC after:	1 week
MFC with:	r221853
2011-05-13 19:35:01 +00:00
Matthew D Fleming
89cb2a19ec Usa a globally visible region of zeros for both /dev/zero and the md
device.  There are likely other kernel uses of "blob of zeros" than can
be converted.

Reviewed by:	alc
MFC after:	1 week
2011-05-13 18:48:00 +00:00
Konstantin Belousov
56bdf2dbc2 Since r218070 reenabled the call to vm_map_simplify_entry() from
vm_map_insert(), the kmem_back() assumption about newly inserted
entry might be broken due to interference of two factors. In the low
memory condition, when vm_page_alloc() returns NULL, supplied map is
unlocked. If another thread performs kmem_malloc() meantime, and its
map entry is placed right next to our thread map entry in the map,
both entries wire count is still 0 and entries are coalesced due to
vm_map_simplify_entry().

Mark new entry with MAP_ENTRY_IN_TRANSITION to prevent coalesce.
Fix some style issues, tighten the assertions to account for
MAP_ENTRY_IN_TRANSITION state.

Reported and tested by:	pho
Reviewed by:	alc
2011-02-15 09:03:58 +00:00
Matthew D Fleming
d69b01efc2 Replace an XXX comment with the appropriate code.
Submitted by:	alc
2010-09-20 20:41:59 +00:00
Matthew D Fleming
e3813573bd Rework memguard(9) to reserve significantly more KVA to detect
use-after-free over a longer time.  Also release the backing pages of
a guarded allocation at free(9) time to reduce the overhead of using
memguard(9).  Allow setting and varying the malloc type at run-time.
Add knobs to allow:

 - randomly guarding memory
 - adding un-backed KVA guard pages to detect underflow and overflow
 - a lower limit on the size of allocations that are guarded

Reviewed by:    alc
Reviewed by:    brueffer, Ulrich Spörlein <uqs spoerlein net> (man page)
Silence from:   -arch
Approved by:    zml (mentor)
MFC after:      1 month
2010-08-11 22:10:37 +00:00
Alan Cox
746c2ddee8 The pages allocated by kmem_alloc_attr() and kmem_malloc() are unmanaged.
Consequently, neither the page lock nor the page queues lock is needed to
unwire and free them.
2010-05-03 07:08:16 +00:00
Kip Macy
2965a45315 On Alan's advice, rather than do a wholesale conversion on a single
architecture from page queue lock to a hashed array of page locks
(based on a patch by Jeff Roberson), I've implemented page lock
support in the MI code and have only moved vm_page's hold_count
out from under page queue mutex to page lock. This changes
pmap_extract_and_hold on all pmaps.

Supported by: Bitgravity Inc.

Discussed with: alc, jeffr, and kib
2010-04-30 00:46:43 +00:00
Juli Mallett
ca596a25f0 o) Add a VM find-space option, VMFS_TLB_ALIGNED_SPACE, which searches the
address space for an address as aligned by the new pmap_align_tlb()
   function, which is for constraints imposed by the TLB. [1]
o) Add a kmem_alloc_nofault_space() function, which acts like
   kmem_alloc_nofault() but allows the caller to specify which find-space
   option to use. [1]
o) Use kmem_alloc_nofault_space() with VMFS_TLB_ALIGNED_SPACE to allocate the
   kernel stack address on MIPS. [1]
o) Make pmap_align_tlb() on MIPS align addresses so that they do not start on
   an odd boundary within the TLB, so that they are suitable for insertion as
   wired entries and do not have to share a TLB entry with another mapping,
   assuming they are appropriately-sized.
o) Eliminate md_realstack now that the kstack will be appropriately-aligned on
   MIPS.
o) Increase the number of guard pages to 2 so that we retain the proper
   alignment of the kstack address.

Reviewed by:	[1] alc
X-MFC-after:	Making sure alc has not come up with a better interface.
2010-04-18 22:32:07 +00:00
Konstantin Belousov
3364c323e6 Implement global and per-uid accounting of the anonymous memory. Add
rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved
for the uid.

The accounting information (charge) is associated with either map entry,
or vm object backing the entry, assuming the object is the first one
in the shadow chain and entry does not require COW. Charge is moved
from entry to object on allocation of the object, e.g. during the mmap,
assuming the object is allocated, or on the first page fault on the
entry. It moves back to the entry on forks due to COW setup.

The per-entry granularity of accounting makes the charge process fair
for processes that change uid during lifetime, and decrements charge
for proper uid when region is unmapped.

The interface of vm_pager_allocate(9) is extended by adding struct ucred *,
that is used to charge appropriate uid when allocation if performed by
kernel, e.g. md(4).

Several syscalls, among them is fork(2), may now return ENOMEM when
global or per-uid limits are enforced.

In collaboration with:	pho
Reviewed by:	alc
Approved by:	re (kensmith)
2009-06-23 20:45:22 +00:00
Konstantin Belousov
655c349022 Revert the addition of the freelist argument for the vm_map_delete()
function, done in r188334. Instead, collect the entries that shall be
freed, in the deferred_freelist member of the map. Automatically purge
the deferred freelist when map is unlocked.

Tested by:	pho
Reviewed by:	alc
2009-02-24 20:57:43 +00:00
Robert Watson
9309e63c1f Put debug.vm_lowmem sysctl under DIAGNOSTIC.
Submitted by:	sam
MFC after:	3 days
2009-02-23 23:30:17 +00:00
Robert Watson
86f087370b Add a debugging sysctl, debug.vm_lowmem, that when assigned a value of
1 will trigger a pass through the VM's low-memory handlers, such as
protocol and UMA drain routines.  This makes it easier to exercise
these otherwise rarely-invoked code paths.

MFC after:	3 days
2009-02-23 23:00:12 +00:00
Konstantin Belousov
897d81a020 Do not call vm_object_deallocate() from vm_map_delete(), because we
hold the map lock there, and might need the vnode lock for OBJT_VNODE
objects. Postpone object deallocation until caller of vm_map_delete()
drops the map lock. Link the map entries to be freed into the freelist,
that is released by the new helper function vm_map_entry_free_freelist().

Reviewed by:	tegge, alc
Tested by:	pho
2009-02-08 20:39:17 +00:00
Alan Cox
fb272dc841 Eliminate stale comments from kmem_malloc(). 2008-07-18 17:41:31 +00:00
Alan Cox
5cfa90e902 Make preparations for increasing the size of the kernel virtual address space
on the amd64 architecture.  The amd64 architecture requires kernel code and
global variables to reside in the highest 2GB of the 64-bit virtual address
space.  Thus, the memory allocated during bootstrap, before the call to
kmem_init(), starts at KERNBASE, which is not necessarily the same as
VM_MIN_KERNEL_ADDRESS on amd64.
2008-06-22 04:54:27 +00:00
Alan Cox
3202ed7523 Introduce a new parameter "superpage_align" to kmem_suballoc() that is
used to request superpage alignment for the submap.

Request superpage alignment for the kmem_map.

Pass VMFS_ANY_SPACE instead of TRUE to vm_map_find().  (They are currently
equivalent but VMFS_ANY_SPACE is the new preferred spelling.)

Remove a stale comment from kmem_malloc().
2008-05-10 21:46:20 +00:00
Alan Cox
2bc24aa956 Eliminate pointless casts from kmem_suballoc(). 2008-04-28 17:25:27 +00:00
Alan Cox
24dedba9f5 Eliminate an unnecessary printf() from kmem_suballoc(). The subsequent
panic() can be extended to convey the same information.
2008-03-30 20:08:59 +00:00
Pawel Jakub Dawidek
79c2840d1d When one tries to allocate memory with the M_WAITOK flag and we are short in
address space in kmem map call vm_lowmem event in a loop and wait a bit for
subsystems to reclaim some memory which in turn will reclaim address space as
well.

Note, this is a work-around.

Reviewed by:	alc
Approved by:	alc
MFC after:	3 days
2008-01-10 08:36:38 +00:00
Alan Cox
eb2a051720 Add an access type parameter to pmap_enter(). It will be used to implement
superpage promotion.

Correct a style error in kmem_malloc(): pmap_enter()'s last parameter is
a Boolean.
2008-01-03 07:34:34 +00:00
Pawel Jakub Dawidek
8ce2d00a04 Change unused 'user_wait' argument to 'timo' argument, which will be
used to specify timeout for msleep(9).

Discussed with:	alc
Reviewed by:	alc
2007-11-07 21:56:58 +00:00
Pawel Jakub Dawidek
0f2c2ce0a3 When KVA is exhausted, try the vm_lowmem event for the last time before
panicing. This helps a lot in ZFS stability.
2007-04-05 20:52:51 +00:00
Alan Cox
9f5c801b94 Change the way that unmanaged pages are created. Specifically,
immediately flag any page that is allocated to a OBJT_PHYS object as
unmanaged in vm_page_alloc() rather than waiting for a later call to
vm_page_unmanage().  This allows for the elimination of some uses of
the page queues lock.

Change the type of the kernel and kmem objects from OBJT_DEFAULT to
OBJT_PHYS.  This allows us to take advantage of the above change to
simplify the allocation of unmanaged pages in kmem_alloc() and
kmem_malloc().

Remove vm_page_unmanage().  It is no longer used.
2007-02-25 06:14:58 +00:00
Alan Cox
e6eaadba43 Declare the map entry created by kmem_init() for the range from
VM_MIN_KERNEL_ADDRESS to the end of the kernel's bootstrap data as
MAP_NOFAULT.
2007-01-07 07:32:04 +00:00
Alan Cox
0f3b612a06 There is no point in setting PG_REFERENCED on kmem_object pages because
they are "unmanaged", i.e., non-pageable, pages.

Remove a stale comment.
2006-11-13 00:27:02 +00:00
Alan Cox
44b8bd66f9 Make pmap_enter() responsible for setting PG_WRITEABLE instead
of its caller.  (As a beneficial side-effect, a high-contention
acquisition of the page queues lock in vm_fault() is eliminated.)
2006-11-12 21:48:34 +00:00
Alan Cox
66bdd5d619 The page queues lock is no longer required by vm_page_wakeup(). 2006-10-23 05:27:31 +00:00
Warner Losh
60727d8b86 /* -> /*- for license, minor formatting changes 2005-01-07 02:29:27 +00:00
Alan Cox
ddf4bb37c8 Use VM_ALLOC_NOBUSY instead of calling vm_page_wakeup(). 2004-10-24 18:46:32 +00:00
Brian Feldman
0ada205ee6 Back out all behavioral chnages. 2004-08-10 14:42:48 +00:00
Brian Feldman
9689d5e5ee Revamp VM map wiring.
* Allow no-fault wiring/unwiring to succeed for consistency;
  however, the wired count remains at zero, so it's a special case.

* Fix issues inside vm_map_wire() and vm_map_unwire() where the
  exact state of user wiring (one or zero) and system wiring
  (zero or more) could be confused; for example, system unwiring
  could succeed in removing a user wire, instead of being an
  error.

* Require all mappings to be unwired before they are deleted.
  When VM space is still wired upon deletion, it will be waited
  upon for the following unwire.  This makes vslock(9) work
  rather than allowing kernel-locked memory to be deleted
  out from underneath of its consumer as it would before.
2004-08-09 19:52:29 +00:00
Alan Cox
5122b74809 For years, kmem_alloc_pageable() has been misused. Now that the last of
these misuses has been corrected, remove it before new ones appear, such as
arm/arm/pmap.c revision 1.8.
2004-07-25 20:08:59 +00:00
Bosko Milekic
099a0e588c Bring in mbuma to replace mballoc.
mbuma is an Mbuf & Cluster allocator built on top of a number of
extensions to the UMA framework, all included herein.

Extensions to UMA worth noting:
  - Better layering between slab <-> zone caches; introduce
    Keg structure which splits off slab cache away from the
    zone structure and allows multiple zones to be stacked
    on top of a single Keg (single type of slab cache);
    perhaps we should look into defining a subset API on
    top of the Keg for special use by malloc(9),
    for example.
  - UMA_ZONE_REFCNT zones can now be added, and reference
    counters automagically allocated for them within the end
    of the associated slab structures.  uma_find_refcnt()
    does a kextract to fetch the slab struct reference from
    the underlying page, and lookup the corresponding refcnt.

mbuma things worth noting:
  - integrates mbuf & cluster allocations with extended UMA
    and provides caches for commonly-allocated items; defines
    several zones (two primary, one secondary) and two kegs.
  - change up certain code paths that always used to do:
    m_get() + m_clget() to instead just use m_getcl() and
    try to take advantage of the newly defined secondary
    Packet zone.
  - netstat(1) and systat(1) quickly hacked up to do basic
    stat reporting but additional stats work needs to be
    done once some other details within UMA have been taken
    care of and it becomes clearer to how stats will work
    within the modified framework.

From the user perspective, one implication is that the
NMBCLUSTERS compile-time option is no longer used.  The
maximum number of clusters is still capped off according
to maxusers, but it can be made unlimited by setting
the kern.ipc.nmbclusters boot-time tunable to zero.
Work should be done to write an appropriate sysctl
handler allowing dynamic tuning of kern.ipc.nmbclusters
at runtime.

Additional things worth noting/known issues (READ):
   - One report of 'ips' (ServeRAID) driver acting really
     slow in conjunction with mbuma.  Need more data.
     Latest report is that ips is equally sucking with
     and without mbuma.
   - Giant leak in NFS code sometimes occurs, can't
     reproduce but currently analyzing; brueffer is
     able to reproduce but THIS IS NOT an mbuma-specific
     problem and currently occurs even WITHOUT mbuma.
   - Issues in network locking: there is at least one
     code path in the rip code where one or more locks
     are acquired and we end up in m_prepend() with
     M_WAITOK, which causes WITNESS to whine from within
     UMA.  Current temporary solution: force all UMA
     allocations to be M_NOWAIT from within UMA for now
     to avoid deadlocks unless WITNESS is defined and we
     can determine with certainty that we're not holding
     any locks when we're M_WAITOK.
   - I've seen at least one weird socketbuffer empty-but-
     mbuf-still-attached panic.  I don't believe this
     to be related to mbuma but please keep your eyes
     open, turn on debugging, and capture crash dumps.

This change removes more code than it adds.

A paper is available detailing the change and considering
various performance issues, it was presented at BSDCan2004:
http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf
Please read the paper for Future Work and implementation
details, as well as credits.

Testing and Debugging:
    rwatson,
    brueffer,
    Ketrien I. Saihr-Kesenchedra,
    ...
Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +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
Dag-Erling Smørgrav
497ddd5807 Back out previous commit due to objections. 2004-02-16 21:36:59 +00:00
Dag-Erling Smørgrav
cbea5fb98f Don't panic if we fail to satisfy an M_WAITOK request; return 0 instead.
The calling code will either handle that gracefully or cause a page fault.
2004-02-16 18:41:58 +00:00
Alan Cox
37d44833d5 Unmanage pages allocated by kmem_alloc(). (There is no point in having PV
entries for these pages.)
2004-01-10 00:22:33 +00:00
Alan Cox
c020e821c7 Don't bother clearing PG_ZERO in contigmalloc1(), kmem_alloc(), or
kmem_malloc().  It serves no purpose.
2004-01-06 20:52:55 +00:00
Alan Cox
ff5dcf2546 - Increase the scope of the kmem_object's lock in kmem_malloc(). Add a
comment explaining why a further increase is not possible.
2004-01-01 19:48:56 +00:00
Alan Cox
53d0a98878 Remove GIANT_REQUIRED from kmem_suballoc(). 2003-12-28 00:10:48 +00:00
Jonathan Mini
8f101a2f31 NFC: Update stale comments.
Reviewed by:	alc
2003-11-10 00:44:00 +00:00
Alan Cox
49c06616ae Synchronize access to a vm page's valid field using the containing
vm object's lock.
2003-10-04 19:13:27 +00:00
Alan Cox
30bb12a4e8 Call vm_page_unmanage() on pages belonging to the kmem_object. This
eliminates the unnecessary overhead of managing "PV" entries for these
pages.
2003-09-14 02:37:59 +00:00
Eivind Eklund
2ae51145e8 Change clean_map from a global to an auto variable 2003-09-01 16:46:47 +00:00
Bruce M Simpson
abd498aa71 Add the mlockall() and munlockall() system calls.
- All those diffs to syscalls.master for each architecture *are*
   necessary. This needed clarification; the stub code generation for
   mlockall() was disabled, which would prevent applications from
   linking to this API (suggested by mux)
 - Giant has been quoshed. It is no longer held by the code, as
   the required locking has been pushed down within vm_map.c.
 - Callers must specify VM_MAP_WIRE_HOLESOK or VM_MAP_WIRE_NOHOLES
   to express their intention explicitly.
 - Inspected at the vmstat, top and vm pager sysctl stats level.
   Paging-in activity is occurring correctly, using a test harness.
 - The RES size for a process may appear to be greater than its SIZE.
   This is believed to be due to mappings of the same shared library
   page being wired twice. Further exploration is needed.
 - Believed to back out of allocations and locks correctly
   (tested with WITNESS, MUTEX_PROFILING, INVARIANTS and DIAGNOSTIC).

PR:             kern/43426, standards/54223
Reviewed by:    jake, alc
Approved by:    jake (mentor)
MFC after:	2 weeks
2003-08-11 07:14:08 +00:00
Mike Silbersack
cebde06978 More pipe changes:
From alc:
Move pageable pipe memory to a seperate kernel submap to avoid awkward
vm map interlocking issues.  (Bad explanation provided by me.)

From me:
Rework pipespace accounting code to handle this new layout, and adjust
our default values to account for the fact that we now have a solid
limit on allocations.

Also, remove the "maxpipes" limit, as it no longer has a purpose.
(The limit on kva usage solves the problem of having two many pipes.)
2003-08-11 05:51:51 +00:00