Commit Graph

2939 Commits

Author SHA1 Message Date
Konstantin Belousov
d4961bcb3a Do not restart scan of the inactive queue when non-inactive page is
found. Rather, we shall not find such pages on inactive queue at all.

Requested and reviewed by:	alc
MFC after:    2 weeks
2012-07-18 21:47:50 +00:00
Alan Cox
85eeca35b9 Move what remains of vm/vm_contig.c into vm/vm_pageout.c, where similar
code resides.  Rename vm_contig_grow_cache() to vm_pageout_grow_cache().

Reviewed by:	kib
2012-07-18 05:21:34 +00:00
Alan Cox
da1ab8a4a0 Correct vm_page_alloc_contig()'s implementation of VM_ALLOC_NODUMP. 2012-07-17 02:36:59 +00:00
Alan Cox
907e4524dc Various improvements to vm_contig_grow_cache(). Most notably, even when
it can't sleep, it can still move clean pages from the inactive queue to
the cache.  Also, when a page is cached, there is no need to restart the
scan.  The "next" page pointer held by vm_contig_launder() is still
valid.  Finally, add a comment summarizing what vm_contig_grow_cache()
does based upon the value of "tries".

MFC after:	3 weeks
2012-07-16 18:13:43 +00:00
Alan Cox
476f7f2423 Correct an off-by-one error in vm_reserv_alloc_contig() that resulted in
the last reservation of a multi-reservation allocation not being
initialized.
2012-07-15 21:46:19 +00:00
Matthew D Fleming
f806cdcf99 Fix a bug with memguard(9) on 32-bit architectures without a
VM_KMEM_MAX_SIZE.

The code was not taking into account the size of the kernel_map, which
the kmem_map is allocated from, so it could produce a sub-map size too
large to fit.  The simplest solution is to ignore VM_KMEM_MAX entirely
and base the memguard map's size off the kernel_map's size, since this
is always relevant and always smaller.

Found by:	Justin Hibbits
2012-07-15 20:29:48 +00:00
Alan Cox
9757857c4f If vm_contig_grow_cache() is allowed to sleep, then invoke the vm_lowmem
handlers.
2012-07-14 20:14:03 +00:00
Alan Cox
0ff0fc84c2 Move kmem_alloc_{attr,contig}() to vm/vm_kern.c, where similarly named
functions reside.  Correct the comment describing kmem_alloc_contig().
2012-07-14 18:10:44 +00:00
Attilio Rao
571a1e92aa Document the object type movements, related to swp_pager_copy(),
in vm_object_collapse() and vm_object_split().

In collabouration with:	alc
MFC after:	3 days
2012-07-11 01:04:59 +00:00
Konstantin Belousov
a4156419ca Avoid vm page queues lock leak after r238212.
Reported and tested by:	Michael Butler <imb protected-networks net>
Reviewed by:	alc
Pointy hat to:	kib
MFC after:	20 days
2012-07-08 18:04:26 +00:00
Konstantin Belousov
48cc2fc774 Drop page queues mutex on each iteration of vm_pageout_scan over the
inactive queue, unless busy page is found.

Dropping the mutex often should allow the other lock acquires to
proceed without waiting for whole inactive scan to finish. On machines
with lot of physical memory scan often need to iterate a lot before it
finishes or finds a page which requires laundring, causing high
latency for other lock waiters.

Suggested and reviewed by:	alc
MFC after:	3 weeks
2012-07-07 19:39:08 +00:00
Eitan Adler
c288b54837 Add missing sleep stat increase
PR:		kern/168211
Submitted by:	linimon
Reviewed by:	alc
Approved by:	cperciva
MFC after:	3 days
2012-07-07 17:46:11 +00:00
Konstantin Belousov
5d10ef2096 Style.
Reviewed by:	alc (previous version)
MFC after:	1 week
2012-07-06 20:13:16 +00:00
John Baldwin
687c94aac9 Honor db_pager_quit in 'show uma' and 'show malloc'.
MFC after:	1 month
2012-07-02 16:14:52 +00:00
Alan Cox
e30df26e7b Add new pmap layer locks to the predefined lock order. Change the names
of a few existing VM locks to follow a consistent naming scheme.
2012-06-27 03:45:25 +00:00
Attilio Rao
ffdd0c7db3 - Add a comment explaining the locking of the cached pages pool held
by vm_objects.
- Add flags for the per-object lock and free pages queue mutex lock.
  Use the newly added flags to mark the cache root within the vm_object
  structure.

Please note that other vm_object members should be marked with correct
locking but they are left for other commits.

In collabouration with:	alc

MFC after:	3 days3 days3 days
2012-06-22 18:34:11 +00:00
Alan Cox
eddc92918e Selectively inline vm_page_dirty(). 2012-06-20 23:25:47 +00:00
John Baldwin
6fbe60fa8b Move the per-thread deferred user map entries list into a private list
in vm_map_process_deferred() which is then iterated to release map entries.
This avoids having a nested vm map unlock operation called from the loop
body attempt to recuse into vm_map_process_deferred().  This can happen if
the vm_map_remove() triggers the OOM killer.

Reviewed by:	alc, kib
MFC after:	1 week
2012-06-20 18:00:26 +00:00
Attilio Rao
db9ba57895 Do a more targeted check on the page cache and avoid to check the cache
pointer directly in vnode_pager_setsize() by using newly introduced
vm_page_is_cached() function.

Reviewed by:	alc
MFC after:	2 weeks
X-MFC:		r234039,234064
2012-06-16 21:39:00 +00:00
Alan Cox
6031c68de4 The page flag PGA_WRITEABLE is set and cleared exclusively by the pmap
layer, but it is read directly by the MI VM layer.  This change introduces
pmap_page_is_write_mapped() in order to completely encapsulate all direct
access to PGA_WRITEABLE in the pmap layer.

Aesthetics aside, I am making this change because amd64 will likely begin
using an alternative method to track write mappings, and having
pmap_page_is_write_mapped() in place allows me to make such a change
without further modification to the MI VM layer.

As an added bonus, tidy up some nearby comments concerning page flags.

Reviewed by:	kib
MFC after:	6 weeks
2012-06-16 18:56:19 +00:00
Konstantin Belousov
83ce08538a Use the previous stack entry protection and max protection to correctly
propagate the stack execution permissions when stack is grown down.

First, curproc->p_sysent->sv_stackprot specifies maximum allowed stack
protection for current ABI, so the new stack entry was typically marked
executable always. Second, for non-main stack MAP_STACK mapping,
the PROT_ flags should be used which were specified at the mmap(2) call
time, and not sv_stackprot.

MFC after:	1 week
2012-06-10 11:31:50 +00:00
Eitan Adler
0a4a2b8e62 Revert r236380
PR:		kern/166780
Requested by:	many
Approved by:	cperciva (implicit)
2012-06-01 18:58:50 +00:00
Eitan Adler
71ee98c97c Add sysctl to query amount of swap space free
PR:		kern/166780
Submitted by:	Radim Kolar <hsn@sendmail.cz>
Approved by:	cperciva
MFC after:	1 week
2012-06-01 04:42:52 +00:00
Maksim Yevmenkin
251386b4b2 Tweak condition for disabling allocation from per-CPU buckets in
low memory situation. I've observed a situation where per-CPU
allocations were disabled while there were enough free cached pages.
Basically, cnt.v_free_count was sitting stable at a value lower
than cnt.v_free_min and that caused massive performance drop.

Reviewed by:	alc
MFC after:	1 week
2012-05-23 18:56:29 +00:00
Konstantin Belousov
4d34e019c4 Calculate the count of per-process cow faults. Export the count to
userspace using the obscure spare int field in struct kinfo_proc.

Submitted by:	Andrey Zonov <andrey zonov org>
MFC after:	1 week
2012-05-23 18:10:54 +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
Andrew Turner
c415e17250 Fix booting on ARM.
In PHYS_TO_VM_PAGE() when VM_PHYSSEG_DENSE is set the check if we are past
the end of vm_page_array was incorrect causing it to return NULL. This
value is then used in vm_phys_add_page causing a data abort.

Reviewed by:	alc, kib, imp
Tested by:	stas
2012-05-22 07:04:23 +00:00
Nathan Whitehorn
ccc4a5c761 Replace the list of PVOs owned by each PMAP with an RB tree. This simplifies
range operations like pmap_remove() and pmap_protect() as well as allowing
simple operations like pmap_extract() not to involve any global state.
This substantially reduces lock coverages for the global table lock and
improves concurrency.
2012-05-20 14:33:28 +00:00
Konstantin Belousov
df2f557df6 Do not double-reference the found vm object in cdev_pager_lookup().
vm_pager_object_lookup() already referenced the object.

Note that there is no in-tree consumers of cdev_pager_lookup(). The
only known user of the function is i915 gem driver, which is not yet
imported. This should make the KPI change minor.

Submitted by:	avg
MFC after:	1 week
2012-05-18 10:23:47 +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
b6de32bd9b Add a facility to register a range of physical addresses to be used
for allocation of fictitious pages, for which PHYS_TO_VM_PAGE()
returns proper fictitious vm_page_t. The range should be de-registered
after consumer stopped using it.

De-inline the PHYS_TO_VM_PAGE() since it now carries code to iterate
over registered ranges.

A hash container might be developed instead of range registration
interface, and fake pages could be put automatically into the hash,
were PHYS_TO_VM_PAGE() could look them up later. This should be
considered before the MFC of the commit is done.

Sponsored by:	The FreeBSD Foundation
Reviewed by:	alc
MFC after:	1 month
2012-05-12 20:42:56 +00:00
Konstantin Belousov
e461aae747 Split the code from vm_page_getfake() to initialize the fake page struct
vm_page into new interface vm_page_initfake(). Handle the case of fake
page re-initialization with changed memattr.

Sponsored by:	The FreeBSD Foundation
Reviewed by:	alc
MFC after:	1 month
2012-05-12 20:34:22 +00:00
Konstantin Belousov
116c213502 Assert that the page passed to vm_page_putfake() is unmanaged.
Sponsored by:	The FreeBSD Foundation
Reviewed by:	alc
MFC after:	1 month
2012-05-12 20:27:51 +00:00
Konstantin Belousov
7900f95d88 Assert that fictitious or unmanaged pages do not appear on
active/inactive lists.

Sponsored by:	The FreeBSD Foundation
Reviewed by:	alc
MFC after:	1 month
2012-05-12 20:24:46 +00:00
Konstantin Belousov
13a0b7bcc4 Commit the change forgotten in r235356.
Sponsored by:	The FreeBSD Foundation
Reviewed by:	alc
MFC after:	1 month
2012-05-12 20:10:18 +00:00
Konstantin Belousov
0c26bb71f6 Make the vm_page_array_size long. Remove redundand zero initialization
for vm_page_array_size and nearby variablees.

Sponsored by:	The FreeBSD Foundation
Reviewed by:	alc
MFC after:	1 month
2012-05-12 20:03:06 +00:00
Alan Cox
13458803f4 Give vm_fault()'s sequential access optimization a makeover.
There are two aspects to the sequential access optimization: (1) read ahead
of pages that are expected to be accessed in the near future and (2) unmap
and cache behind of pages that are not expected to be accessed again.  This
revision changes both aspects.

The read ahead optimization is now more effective.  It starts with the same
initial read window as before, but arithmetically grows the window on
sequential page faults.  This can yield increased read bandwidth.  For
example, on one of my machines, a program using mmap() to read a file that
is several times larger than the machine's physical memory takes about 17%
less time to complete.

The unmap and cache behind optimization is now more selectively applied.
The read ahead window must grow to its maximum size before unmap and cache
behind is performed.  This significantly reduces the number of times that
pages are unmapped and cached only to be reactivated a short time later.

The unmap and cache behind optimization now clears each page's referenced
flag.  Previously, in the case of dirty pages, if the containing file was
still mapped at the time that the page daemon examined the dirty pages,
they would be reactivated.

From a stylistic standpoint, this revision also cleanly separates the
implementation of the read ahead and unmap/cache behind optimizations.

Glanced at:	kib
MFC after:	2 weeks
2012-05-10 15:16:42 +00:00
Nathan Whitehorn
0b852c03eb Avoid a lock order reversal in pmap_extract_and_hold() from relocking
the page. This PMAP requires an additional lock besides the PMAP lock
in pmap_extract_and_hold(), which vm_page_pa_tryrelock() did not release.

Suggested by:	kib
MFC after:	4 days
2012-04-22 17:58:30 +00:00
Konstantin Belousov
1472f4f4b9 When MAP_STACK mapping is created, the map entry is created only to
cover the initial stack size. For MCL_WIREFUTURE maps, the subsequent
call to vm_map_wire() to wire the whole stack region fails due to
VM_MAP_WIRE_NOHOLES flag.

Use the VM_MAP_WIRE_HOLESOK to only wire mapped part of the stack.

Reported and tested by:	Sushanth Rai <sushanth_rai yahoo com>
Reviewed by:	alc
MFC after:	1 week
2012-04-21 18:36:53 +00:00
Alan Cox
2aa163dc57 As documented in vm_page.h, updates to the vm_page's flags no longer
require the page queues lock.

MFC after:	1 week
2012-04-21 18:26:16 +00:00
Attilio Rao
a0f2c37b6f - Introduce a cache-miss optimization for consistency with other
accesses of the cache member of vm_object objects.
- Use novel vm_page_is_cached() for checks outside of the vm subsystem.

Reviewed by:	alc
MFC after:	2 weeks
X-MFC:		r234039
2012-04-09 17:05:18 +00:00
Alan Cox
1c8279e4e7 Fix mincore(2) so that it reports PG_CACHED pages as resident.
MFC after:	2 weeks
2012-04-08 18:25:12 +00:00
Alan Cox
908e3da10e If a page belonging a reservation is cached, then mark the reservation so
that it will be freed to the cache pool rather than the default pool.
Otherwise, the cached pages within the reservation may be recycled sooner
than necessary.

Reported by:	Andrey Zonov
2012-04-08 17:00:46 +00:00
Attilio Rao
d1aa86e151 Staticize vm_page_cache_remove().
Reviewed by:	alc
2012-04-06 20:34:00 +00:00
Nathan Whitehorn
57bd5cce62 Reduce the frequency that the PowerPC/AIM pmaps invalidate instruction
caches, by invalidating kernel icaches only when needed and not flushing
user caches for shared pages.

Suggested by:	kib
MFC after:	2 weeks
2012-04-06 16:03:38 +00:00
John Baldwin
35818d2e94 Add new ktrace records for the start and end of VM faults. This gives
a pair of records similar to syscall entry and return that a user can
use to determine how long page faults take.  The new ktrace records are
enabled via the 'p' trace type, and are enabled in the default set of
trace points.

Reviewed by:	kib
MFC after:	2 weeks
2012-04-05 17:13:14 +00:00
Kirk McKusick
1faacf5d09 Keep track of the mount point associated with a special device
to enable the collection of counts of synchronous and asynchronous
reads and writes for its associated filesystem. The counts are
displayed using `mount -v'.

Ensure that buffers used for paging indicate the vnode from
which they are operating so that counts of paging I/O operations
from the filesystem are collected.

This checkin only adds the setting of the mount point for the
UFS/FFS filesystem, but it would be trivial to add the setting
and clearing of the mount point at filesystem mount/unmount
time for other filesystems too.

Reviewed by: kib
2012-03-28 20:49:11 +00:00
Alan Cox
5730afc9b6 Handle spurious page faults that may occur in no-fault sections of the
kernel.

When access restrictions are added to a page table entry, we flush the
corresponding virtual address mapping from the TLB.  In contrast, when
access restrictions are removed from a page table entry, we do not
flush the virtual address mapping from the TLB.  This is exactly as
recommended in AMD's documentation.  In effect, when access
restrictions are removed from a page table entry, AMD's MMUs will
transparently refresh a stale TLB entry.  In short, this saves us from
having to perform potentially costly TLB flushes.  In contrast,
Intel's MMUs are allowed to generate a spurious page fault based upon
the stale TLB entry.  Usually, such spurious page faults are handled
by vm_fault() without incident.  However, when we are executing
no-fault sections of the kernel, we are not allowed to execute
vm_fault().  This change introduces special-case handling for spurious
page faults that occur in no-fault sections of the kernel.

In collaboration with:	kib
Tested by:		gibbs (an earlier version)

I would also like to acknowledge Hiroki Sato's assistance in
diagnosing this problem.

MFC after:	1 week
2012-03-22 04:52:51 +00:00
John Baldwin
d6e9b97b3f Bah, just revert my earlier change entirely. (Missed alc's request to do
this earlier.)

Requested by:	alc
2012-03-19 19:06:40 +00:00
John Baldwin
92a5994685 Fix madvise(MADV_WILLNEED) to properly handle individual mappings larger
than 4GB.  Specifically, the inlined version of 'ptoa' of the the 'int'
count of pages overflowed on 64-bit platforms.  While here, change
vm_object_madvise() to accept two vm_pindex_t parameters (start and end)
rather than a (start, count) tuple to match other VM APIs as suggested
by alc@.
2012-03-19 18:47:34 +00:00