Commit Graph

124 Commits

Author SHA1 Message Date
Jeff Roberson
98082691bb - Make 'struct buf *buf' private to vfs_bio.c. Having a global variable
'buf' is inconvenient and has lead me to some irritating to discover
   bugs over the years.  It also makes it more challenging to refactor
   the buf allocation system.
 - Move swbuf and declare it as an extern in vfs_bio.c.  This is still
   not perfect but better than it was before.
 - Eliminate the unused ffs function that relied on knowledge of the buf
   array.
 - Move the shutdown code that iterates over the buf array into vfs_bio.c.

Reviewed by:	kib
Sponsored by:	EMC / Isilon Storage Division
2015-07-29 02:26:57 +00:00
Jeff Roberson
fade8dd714 Refactor unmapped buffer address handling.
- Use pointer assignment rather than a combination of pointers and
   flags to switch buffers between unmapped and mapped.  This eliminates
   multiple flags and generally simplifies the logic.
 - Eliminate b_saveaddr since it is only used with pager bufs which have
   their b_data re-initialized on each allocation.
 - Gather up some convenience routines in the buffer cache for
   manipulating buf space and buf malloc space.
 - Add an inline, buf_mapped(), to standardize checks around unmapped
   buffers.

In collaboration with: mlaier
Reviewed by:	kib
Tested by:	pho (many small revisions ago)
Sponsored by:	EMC / Isilon Storage Division
2015-07-23 19:13:41 +00:00
Gleb Smirnoff
093ebe1d28 o Un-inline vm_pager_get_pages(), vm_pager_get_pages_async().
o Provide an extensive set of assertions for input array of pages.
o Remove now duplicate assertions from different pagers.

Sponsored by:	Nginx, Inc.
Sponsored by:	Netflix
2015-06-17 22:44:27 +00:00
Gleb Smirnoff
4d6481a4c9 o Enhance vm_pager_free_nonreq() function:
- Allow to call the function with vm object lock held.
  - Allow to specify reqpage that doesn't match any page in the region,
    meaning freeing all pages.
o Utilize the new function in couple more places in vnode pager.

Reviewed by:	alc, kib
Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2015-03-17 19:19:19 +00:00
Gleb Smirnoff
73e9030e61 - In vnode_pager_generic_getpages() use different free counters for
synchronous and asynchronous requests.  The latter can saturate the
  I/O and we do not want them to affect regular paging.
- Allocate the pbuf at the very beginning of the function, so that
  if we are low on certain kind of pbufs don't even proceed to BMAP,
  but sleep.

Reviewed by:	kib
Sponsored by:	Nginx, Inc.
Sponsored by:	Netflix
2015-03-06 14:15:30 +00:00
Alan Cox
396b3e34b4 Avoid an exclusive acquisition of the object lock on the expected execution
path through the NFS clients' getpages functions.

Introduce vm_pager_free_nonreq().  This function can be used to eliminate
code that is duplicated in many getpages functions.  Also, in contrast to
the code that currently appears in those getpages functions,
vm_pager_free_nonreq() avoids acquiring an exclusive object lock in one
case.

Reviewed by:	kib
MFC after:	6 weeks
Sponsored by:	EMC / Isilon Storage Division
2014-09-14 18:07:55 +00:00
Jeff Roberson
5f51836645 - Add a general purpose resource allocator, vmem, from NetBSD. It was
originally inspired by the Solaris vmem detailed in the proceedings
   of usenix 2001.  The NetBSD version was heavily refactored for bugs
   and simplicity.
 - Use this resource allocator to allocate the buffer and transient maps.
   Buffer cache defrags are reduced by 25% when used by filesystems with
   mixed block sizes.  Ultimately this may permit dynamic buffer cache
   sizing on low KVA machines.

Discussed with:	alc, kib, attilio
Tested by:	pho
Sponsored by:	EMC / Isilon Storage Division
2013-06-28 03:51:20 +00:00
Jeff Roberson
26089666b6 Prepare to replace the buf splay with a trie:
- Don't insert BKGRDMARKER bufs into the splay or dirty/clean buf lists.
   No consumers need to find them there and it complicates the tree.
   These flags are all FFS specific and could be moved out of the buf
   cache.
 - Use pbgetvp() and pbrelvp() to associate the background and journal
   bufs with the vp.  Not only is this much cheaper it makes more sense
   for these transient bufs.
 - Fix the assertions in pbget* and pbrel*.  It's not safe to check list
   pointers which were never initialized.  Use the BX flags instead.  We
   also check B_PAGING in reassignbuf() so this should cover all cases.

Discussed with:	kib, mckusick, attilio
Sponsored by:	EMC / Isilon Storage Division
2013-04-06 22:21:23 +00:00
Attilio Rao
89f6b8632c Switch the vm_object mutex to be a rwlock. This will enable in the
future further optimizations where the vm_object lock will be held
in read mode most of the time the page cache resident pool of pages
are accessed for reading purposes.

The change is mostly mechanical but few notes are reported:
* The KPI changes as follow:
  - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK()
  - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK()
  - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK()
  - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED()
    (in order to avoid visibility of implementation details)
  - The read-mode operations are added:
    VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(),
    VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED()
* The vm/vm_pager.h namespace pollution avoidance (forcing requiring
  sys/mutex.h in consumers directly to cater its inlining functions
  using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h
  consumers now must include also sys/rwlock.h.
* zfs requires a quite convoluted fix to include FreeBSD rwlocks into
  the compat layer because the name clash between FreeBSD and solaris
  versions must be avoided.
  At this purpose zfs redefines the vm_object locking functions
  directly, isolating the FreeBSD components in specific compat stubs.

The KPI results heavilly broken by this commit.  Thirdy part ports must
be updated accordingly (I can think off-hand of VirtualBox, for example).

Sponsored by:	EMC / Isilon storage division
Reviewed by:	jeff
Reviewed by:	pjd (ZFS specific review)
Discussed with:	alc
Tested by:	pho
2013-03-09 02:32:23 +00:00
Andriy Gapon
b6062382be vm_pager_object_lookup: small performance optimization
do not needlessly lock an object if its handle doesn't match

Reviewed by:	kib, alc
MFC after:	1 week
2012-05-23 12:51:49 +00:00
Konstantin Belousov
b7ac5a8571 Add new pager type, OBJT_MGTDEVICE. It provides the device pager
which carries fictitous managed pages. In particular, the consumers of
the new object type can remove all mappings of the device page with
pmap_remove_all().

The range of physical addresses used for fake page allocation shall be
registered with vm_phys_fictitious_reg_range() interface to allow the
PHYS_TO_VM_PAGE() to work in pmap.

Most likely, only i386 and amd64 pmaps can handle fictitious managed
pages right now.

Sponsored by:	The FreeBSD Foundation
Reviewed by:	alc
MFC after:	1 month
2012-05-12 20:49:58 +00:00
Konstantin Belousov
bf277cf450 Remove the condition that is always true.
Submitted by:	alc
MFC after:	1 week
2011-11-15 14:09:53 +00:00
Alan Cox
2c4992db70 Move the definition of M_VMPGDATA to the swap pager, where the only
remaining uses are.
2011-01-18 04:54:43 +00:00
John Baldwin
013818111a Add a new type of VM object: OBJT_SG. An OBJT_SG object is very similar to
a device pager (OBJT_DEVICE) object in that it uses fictitious pages to
provide aliases to other memory addresses.  The primary difference is that
it uses an sglist(9) to determine the physical addresses for a given offset
into the object instead of invoking the d_mmap() method in a device driver.

Reviewed by:	alc
Approved by:	re (kensmith)
MFC after:	2 weeks
2009-07-24 13:50:29 +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
Roman Divacky
af83f5d77c Change the functions to ANSI in those cases where it breaks promotion
to int rule. See ISO C Standard: SS6.7.5.3:15.

Approved by:	kib (mentor)
Reviewed by:	warner
Tested by:	silence on -current
2009-02-24 18:09:31 +00:00
Alan Cox
b5e8f167b9 Consider a scenario in which one processor, call it Pt, is performing
vm_object_terminate() on a device-backed object at the same time that
another processor, call it Pa, is performing dev_pager_alloc() on the
same device.  The problem is that vm_pager_object_lookup() should not be
allowed to return a doomed object, i.e., an object with OBJ_DEAD set,
but it does.  In detail, the unfortunate sequence of events is: Pt in
vm_object_terminate() holds the doomed object's lock and sets OBJ_DEAD
on the object.  Pa in dev_pager_alloc() holds dev_pager_sx and calls
vm_pager_object_lookup(), which returns the doomed object.  Next, Pa
calls vm_object_reference(), which requires the doomed object's lock, so
Pa waits for Pt to release the doomed object's lock.  Pt proceeds to the
point in vm_object_terminate() where it releases the doomed object's
lock.  Pa is now able to complete vm_object_reference() because it can
now complete the acquisition of the doomed object's lock.  So, now the
doomed object has a reference count of one!  Pa releases dev_pager_sx
and returns the doomed object from dev_pager_alloc().  Pt now acquires
dev_pager_mtx, removes the doomed object from dev_pager_object_list,
releases dev_pager_mtx, and finally calls uma_zfree with the doomed
object.  However, the doomed object is still in use by Pa.

Repeating my key point, vm_pager_object_lookup() must not return a
doomed object.  Moreover, the test for the object's state, i.e.,
doomed or not, and the increment of the object's reference count
should be carried out atomically.

Reviewed by:	kib
Approved by:	re (kensmith)
MFC after:	3 weeks
2007-08-05 21:04:32 +00:00
Robert Watson
5bb84bc84b Normalize a significant number of kernel malloc type names:
- Prefer '_' to ' ', as it results in more easily parsed results in
  memory monitoring tools such as vmstat.

- Remove punctuation that is incompatible with using memory type names
  as file names, such as '/' characters.

- Disambiguate some collisions by adding subsystem prefixes to some
  memory types.

- Generally prefer lower case to upper case.

- If the same type is defined in multiple architecture directories,
  attempt to use the same name in additional cases.

Not all instances were caught in this change, so more work is required to
finish this conversion.  Similar changes are required for UMA zone names.
2005-10-31 15:41:29 +00:00
Alexander Kabaev
857b66d505 Do not use vm_pager_init() to initialize vnode_pbuf_freecnt variable.
vm_pager_init() is run before required nswbuf variable has been set
to correct value. This caused system to run with single pbuf available
for vnode_pager. Handle both cluster_pbuf_freecnt and vnode_pbuf_freecnt
variable in the same way.

Reported by:	ade
Obtained from:	alc
MFC after:	2 days
2005-08-13 20:21:33 +00:00
Alan Cox
ab973359d5 Remove calls to spl*(). 2005-05-18 20:45:33 +00:00
Poul-Henning Kamp
253de0a143 Make npages static and const. 2005-02-10 12:18:17 +00:00
Warner Losh
60727d8b86 /* -> /*- for license, minor formatting changes 2005-01-07 02:29:27 +00:00
Poul-Henning Kamp
5c6e573ffb Add pbgetbo()/pbrelbo() lighter weight versions of pbgetvp()/pbrelvp(). 2004-11-15 08:47:18 +00:00
Poul-Henning Kamp
287013d287 More kasserts. 2004-11-15 08:33:09 +00:00
Poul-Henning Kamp
d7fe1f51ad style polishing. 2004-11-15 08:22:38 +00:00
Poul-Henning Kamp
a752aa8f17 Move pbgetvp() and pbrelvp() to vm_pager.c with the rest of the pbuf stuff. 2004-11-15 08:12:50 +00:00
Poul-Henning Kamp
e8a7bef39e expect the caller to have called pbrelvp() if necessary. 2004-11-15 08:07:26 +00:00
Poul-Henning Kamp
6e67e2a710 Retire b_magic now, we have the bufobj containing the same hint. 2004-11-04 09:48:18 +00:00
Poul-Henning Kamp
b792bebeea Move the buffer method vector (buf->b_op) to the bufobj.
Extend it with a strategy method.

Add bufstrategy() which do the usual VOP_SPECSTRATEGY/VOP_STRATEGY
song and dance.

Rename ibwrite to bufwrite().

Move the two NFS buf_ops to more sensible places, add bufstrategy
to them.

Add inlines for bwrite() and bstrategy() which calls through
buf->b_bufobj->b_ops->b_{write,strategy}().

Replace almost all VOP_STRATEGY()/VOP_SPECSTRATEGY() calls with bstrategy().
2004-10-24 20:03:41 +00:00
Alan Cox
41f1b2c460 The demise of vm_pager_map_page() in revision 1.93 of vm/vm_pager.c permits
the reduction of the pager map's size by 8M bytes.  In other words, eight
megabytes of largely wasted KVA are returned to the kernel map for use
elsewhere.
2004-04-08 19:08:49 +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
9e0ddbd00a Eliminate vm_pager_map_page() and vm_pager_unmap_page() and their uses.
Use sf_buf_alloc() and sf_buf_free() instead.
2004-04-06 07:12:32 +00:00
Alan Cox
3ad8097fd4 - Remove comments referring to functions that no longer exist. 2003-10-20 05:16:27 +00:00
Poul-Henning Kamp
4e6586002d Use sparse struct initializations for struct pagerops.
This makes grepping for which pagers implement which methods easier.
2003-08-05 06:51:26 +00:00
Alan Cox
981371629a Use kmem_alloc_nofault() instead of kmem_alloc_pageable() to allocate
swapbkva.  Swapbkva mappings are explicitly managed using pmap_qenter(),
not on-demand by vm_fault(), making kmem_alloc_nofault() more appropriate.

Submitted by:	tegge
2003-08-04 04:35:04 +00:00
Poul-Henning Kamp
745f330503 Move extern declaration of the various pagerops from vm_pager.c
to vm_pager.h where the various pagers will also see them.
2003-08-03 09:27:39 +00:00
Poul-Henning Kamp
adece6e592 Initialize b_saveaddr when we hand out pbufs 2003-06-20 08:35:28 +00:00
David E. O'Brien
874651b13c Use __FBSDID(). 2003-06-11 23:50:51 +00:00
Alan Cox
658ad5fff5 Lock the vm_object when performing vm_pager_deallocate(). 2003-05-06 02:45:28 +00:00
Alan Cox
2ac8b16089 Remove GIANT_REQUIRED from getpbuf(). Reviewed by: tegge
Reduce pbuf_mtx's scope in relpbuf().  Submitted by: tegge
2003-04-05 21:01:16 +00:00
Jeff Roberson
17661e5ac4 - Add an interlock argument to BUF_LOCK and BUF_TIMELOCK.
- Remove the buftimelock mutex and acquire the buf's interlock to protect
   these fields instead.
 - Hold the vnode interlock while locking bufs on the clean/dirty queues.
   This reduces some cases from one BUF_LOCK with a LK_NOWAIT and another
   BUF_LOCK with a LK_TIMEFAIL to a single lock.

Reviewed by:	arch, mckusick
2003-02-25 03:37:48 +00:00
Alan Cox
c2eda4b565 o Remove some long dead code: from revision 1.41 of vm/vm_pager.c
3+ years ago.
 o Remove some unused prototypes.
2002-07-01 02:38:05 +00:00
Alan Cox
7942194583 o Remove GIANT_REQUIRED from vm_pager_allocate() and vm_pager_deallocate(). 2002-06-21 05:04:56 +00:00
John Baldwin
6008862bc2 Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on:	i386, alpha, sparc64
2002-04-04 21:03:38 +00:00
Alfred Perlstein
11caded34f Remove __P. 2002-03-19 22:20:14 +00:00
Jake Burkholder
ac59490b5e Convert all pmap_kenter/pmap_kremove pairs in MI code to use pmap_qenter/
pmap_qremove.  pmap_kenter is not safe to use in MI code because it is not
guaranteed to flush the mapping from the tlb on all cpus.  If the process
in question is preempted and migrates cpus between the call to pmap_kenter
and pmap_kremove, the original cpu will be left with stale mappings in its
tlb.  This is currently not a problem for i386 because we do not use PG_G on
SMP, and thus all mappings are flushed from the tlb on context switches, not
just user mappings.  This is not the case on all architectures, and if PG_G
is to be used with SMP on i386 it will be a problem.  This was committed by
peter earlier as part of his fine grained tlb shootdown work for i386, which
was backed out for other reasons.

Reviewed by:	peter
2002-03-17 00:56:41 +00:00
Eivind Eklund
a128794977 - 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
Eivind Eklund
f52bd684f3 * Move bswlist declaration and initialization from kern/vfs_bio.c to
vm/vm_pager.c, which is the only place it is used.
* Make the QUEUE_* definitions and bufqueues local to vfs_bio.c.
* constify buf_wmesg.
2002-03-05 18:20:58 +00:00
Peter Wemm
d1693e1701 Back out all the pmap related stuff I've touched over the last few days.
There is some unresolved badness that has been eluding me, particularly
affecting uniprocessor kernels.  Turning off PG_G helped (which is a bad
sign) but didn't solve it entirely.  Userland programs still crashed.
2002-02-27 09:51:33 +00:00
Peter Wemm
bd1e3a0f89 Jake further reduced IPI shootdowns on sparc64 in loops by using ranged
shootdowns in a couple of key places.  Do the same for i386.  This also
hides some physical addresses from higher levels and has it use the
generic vm_page_t's instead.  This will help for PAE down the road.

Obtained from:	jake (MI code, suggestions for MD part)
2002-02-27 02:14:58 +00:00