Commit Graph

4600 Commits

Author SHA1 Message Date
Doug Moore
9f32cb5b1c Set uninitialized popmap bits in vm_reserv_init
In vm_reserv_init, set all the marker popmap bits in vm_reserv_init,
and not just the bits of the first popmap entry.

Reviewed by:	markj
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D33258
2021-12-05 17:17:25 -06:00
Gleb Smirnoff
2cb67bd798 uma: remove unused *item argument from cache_free()
Reviewed by:		markj
Differential revision:	https://reviews.freebsd.org/D33272
2021-12-05 10:44:47 -08:00
Mark Johnston
39a7396f5d vm_page: Tighten the object lock assertion in vm_page_invalid()
A page must not become invalid while vm_fault_soft_fast() is attempting
to map unbusied pages for reading.

Note that all callers hold the object write lock already, and
vm_page_set_invalid() asserts the object write lock.

Reviewed by:	kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D33250
2021-12-05 10:51:11 -05:00
Konstantin Belousov
e8dc2ba29c swapoff(2): add a SWAPOFF_FORCE flag
The flag requests skipping the heuristic which tries to avoid leaving
system with more allocated memory than available from RAM and remanining
swap.

Reviewed by:	markj
Discussed with:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D33165
2021-12-05 00:20:58 +02:00
Konstantin Belousov
a4e4132fa3 swapoff(2): replace special device name argument with a structure
For compatibility, add a placeholder pointer to the start of the
added struct swapoff_new_args, and use it to distinguish old vs. new
style of syscall invocation.

Reviewed by:	markj
Discussed with:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D33165
2021-12-05 00:20:58 +02:00
Konstantin Belousov
6df359449f swap_pager.c: Remove MPSAFE and ARGSUSED annotations
Reviewed by:	markj
Discussed with:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D33165
2021-12-05 00:20:58 +02:00
Konstantin Belousov
0190c38b9d swapoff_one(): only check free pages count manually turning swap off
When swap is turned off due to system shutdown or reboot, ignore the
check.  Problem is that the check is not accurate by any means, free
page count can legitimately be low while system still able to page in
everything from the swap.  Then, we turn swap off if swapping on
real file or some non-standard geom provider, and typically panic
when system appears to actually need to unavailable page.

For syscall, it is better to be safe than sorry.

Reported and tested by:	peterj
Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D33147
2021-11-29 18:38:02 +02:00
Mateusz Guzik
7e1d3eefd4 vfs: remove the unused thread argument from NDINIT*
See b4a58fbf64 ("vfs: remove cn_thread")

Bump __FreeBSD_version to 1400043.
2021-11-25 22:50:42 +00:00
Konstantin Belousov
b19740f4ce swap_pager: lock vnode in swapdev_strategy()
VOP_STRATEGY() requires locked vnode.  Note that we lock the swap vnode
while pages are busy, but this would only cause real LoR if pages belong
to the swap vnode, which must not be the case for correct use.

Reported and tested by:	peterj
Reviewed by:	markj
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D33119
2021-11-25 21:34:50 +02:00
Konstantin Belousov
6ddf41faa6 swapon: extend the region where the swap vnode is locked
to cover VOP_GETATTR() call in sys_swapon().  Move locking from inside
swapongeom() and swaponvp() into sys_swapon().

Reported by and tested by:	peterj
Reviewed by:	markj
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D33119
2021-11-25 21:34:44 +02:00
Konstantin Belousov
a6d04f34a4 swap pager: lock vnode around VOP_CLOSE()
Reported and tested by:	peterj
Reviewed by:	markj
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D33119
2021-11-25 21:34:39 +02:00
Mark Johnston
d47d3a94bb vm_fault: Factor out per-object operations into vm_fault_object()
No functional change intended.

Obtained from:	jeff (object_concurrency patches)
Reviewed by:	kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D33018
2021-11-24 14:02:56 -05:00
Mark Johnston
f1b642c255 vm_fault: Introduce a fault_status enum for internal return types
Rather than overloading the meanings of the Mach statuses, introduce a
new set for use internally in the fault code.  This makes the control
flow easier to follow and provides some extra error checking when a
fault status variable is used in a switch statement.

vm_fault_lookup() and vm_fault_relookup() continue to use Mach statuses
for now, as there isn't much benefit to converting them and they
effectively pass through a status from vm_map_lookup().

Obtained from:	jeff (object_concurrency patches)
Reviewed by:	kib
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D33017
2021-11-24 14:02:55 -05:00
Mark Johnston
45c09a74d6 vm_fault: Move nera into faultstate
This makes it easier to factor out pieces of vm_fault().  No functional
change intended.

Obtained from:	jeff (object_concurrency patches)
Reviewed by:	kib
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D33016
2021-11-24 14:02:55 -05:00
Mitchell Horne
10fe6f80a6 minidump: Use the provided dump bitset
When constructing the set of dumpable pages, use the bitset provided by
the state argument, rather than assuming vm_page_dump invariably. For
normal kernel minidumps this will be a pointer to vm_page_dump, but when
dumping the live system it will not.

To do this, the functions in vm_dumpset.h are extended to accept the
desired bitset as an argument. Note that this provided bitset is assumed
to be derived from vm_page_dump, and therefore has the same size.

Reviewed by:	kib, markj, jhb
MFC after:	2 weeks
Sponsored by:	Juniper Networks, Inc.
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D31992
2021-11-19 15:05:52 -04:00
Brooks Davis
01ce7fca44 ommap: fix signed len and pos arguments
4.3 BSD's mmap took an int len and long pos.  Reject negative lengths
and in freebsd32 sign-extend pos correctly rather than mis-handling
negative positions as large positive ones.

Reviewed by:	kib
2021-11-15 18:34:28 +00:00
Mark Johnston
d28af1abf0 vm: Add a mode to vm_object_page_remove() which skips invalid pages
This will be used to break a deadlock in ZFS between the per-mountpoint
teardown lock and page busy locks.  In particular, when purging data
from the page cache during dataset rollback, we want to avoid blocking
on the busy state of invalid pages since the busying thread may be
blocked on the teardown lock in zfs_getpages().

Add a helper, vn_pages_remove_valid(), for use by filesystems.  Bump
__FreeBSD_version so that the OpenZFS port can make use of the new
helper.

PR:		258208
Reviewed by:	avg, kib, sef
Tested by:	pho (part of a larger patch)
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32931
2021-11-15 13:01:30 -05:00
Mark Johnston
a2665158d0 vm_page: Remove vm_page_sbusy() and vm_page_xbusy()
They are unused today and cannot be safely used in the face of unlocked
lookup, in which pages may be busied without the object lock held.

Obtained from:	jeff (object_concurrency patches)
Reviewed by:	kib
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D32948
2021-11-15 13:01:30 -05:00
Mark Johnston
87b646630c vm_page: Consolidate page busy sleep mechanisms
- Modify vm_page_busy_sleep() and vm_page_busy_sleep_unlocked() to take
  a VM_ALLOC_* flag indicating whether to sleep on shared-busy, and fix
  up callers.
- Modify vm_page_busy_sleep() to return a status indicating whether the
  object lock was dropped, and fix up callers.
- Convert callers of vm_page_sleep_if_busy() to use vm_page_busy_sleep()
  instead.
- Remove vm_page_sleep_if_(x)busy().

No functional change intended.

Obtained from:	jeff (object_concurrency patches)
Reviewed by:	kib
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D32947
2021-11-15 13:01:30 -05:00
Mark Johnston
b0acc3f11b vm_pager: Optimize an assertion
Obtained from:	jeff (object_concurrency patches)
Reviewed by:	kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D32946
2021-11-15 13:01:30 -05:00
Mark Johnston
e4bdb6857a vm_page: Handle VM_ALLOC_NORECLAIM in the contiguous page allocator
We added _NORECLAIM to request that kmem_alloc_contig_pages() not spend
time scanning physical memory for candidates to reclaim.  In some
situations the scanning can induce large amounts of undesirable latency,
and it's less important that the request be satisfied than it is that we
not spend many milliseconds scanning.

The problem extends to vm_reserv_reclaim_contig(), which unlike
vm_reserv_reclaim() may have to scan the entire list of partially
populated reservations.  Use VM_ALLOC_NORECLAIM to request that this
scan not be executed.[1]

As a side effect, this fixes a regression in 02fb0585e7 ("vm_page:
Drop handling of VM_ALLOC_NOOBJ in vm_page_alloc_contig_domain()")
where VM_ALLOC_CONTIG was not included in VPAC_FLAGS or VPANC_FLAGS even
though it is not masked by kmem_alloc_contig_pages().[2]

Reported by:	gallatin [1], glebius [2]
Reviewed by:	alc, glebius, kib
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32899
2021-11-11 14:26:41 -05:00
Gordon Bergling
c28e39c3d6 Fix a common typo in syctl descriptions
- s/maxiumum/maximum/

MFC after:	3 days
2021-11-03 20:49:24 +01:00
Mark Johnston
7585c5db25 uma: Fix handling of reserves in zone_import()
Kegs with no items reserved have uk_reserve = 0.  So the check
keg->uk_reserve >= dom->ud_free_items will be true once all slabs are
depleted.  Then, rather than go and allocate a fresh slab, we return to
the cache layer.

The intent was to do this only when the keg actually has a reserve, so
modify the check to verify this first.  Another approach would be to
make uk_reserve signed and set it to -1 until uma_zone_reserve() is
called, but this requires a few casts elsewhere.

Fixes:	1b2dcc8c54 ("uma: Avoid depleting keg reserves when filling a bucket")
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32516
2021-11-01 09:51:43 -04:00
Mark Johnston
fab343a716 uma: Improve M_USE_RESERVE handling in keg_fetch_slab()
M_USE_RESERVE is used in a couple of places in the VM to avoid unbounded
recursion when the direct map is not available, as is the case on 32-bit
platforms or when certain kernel sanitizers (KASAN and KMSAN) are
enabled.  For example, to allocate KVA, the kernel might allocate a
kernel map entry, which might require a new slab, which requires KVA.

For these zones, we use uma_prealloc() to populate a reserve of items,
and then in certain serialized contexts M_USE_RESERVE can be used to
guarantee a successful allocation.  uma_prealloc() allocates the
requested number of items, distributing them evenly among NUMA domains.
Thus, in a first-touch zone, to satisfy an M_USE_RESERVE allocation we
might have to check the slab lists of other domains than the current one
to provide the semantics expected by consumers.

So, try harder to find an item if M_USE_RESERVE is specified and the keg
doesn't have anything for current (first-touch) domain.  Specifically,
fall back to a round-robin slab allocation.  This change fixes boot-time
panics on NUMA systems with KASAN or KMSAN enabled.[1]

Alternately we could have uma_prealloc() allocate the requested number
of items for each domain, but for some existing consumers this would be
quite wasteful.  In general I think keg_fetch_slab() should try harder
to find free slabs in other domains before trying to allocate fresh
ones, but let's limit this to M_USE_RESERVE for now.

Also fix a separate problem that I noticed: in a non-round-robin slab
allocation with M_WAITOK, rather than sleeping after a failed slab
allocation we simply try again.  Call vm_wait_domain() before retrying.

Reported by:	mjg, tuexen [1]
Reviewed by:	alc
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32515
2021-11-01 09:51:18 -04:00
Konstantin Belousov
350fc36b4c sysctl vm.objects: yield if hog
Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D31163
2021-10-25 20:34:02 +03:00
Konstantin Belousov
7738118e9a vm.objects_swap: disable reporting some information
For making the call faster, do not count active/inactive object queues,
and do not report vnode info if any (for tmpfs).

Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D31163
2021-10-25 20:34:01 +03:00
Konstantin Belousov
42812ccc96 Add vm.swap_objects sysctl
Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D31163
2021-10-25 20:34:01 +03:00
Konstantin Belousov
1b610624fd vm_object_list: split sysctl handler in separate function
Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D31163
2021-10-25 20:34:01 +03:00
Mark Johnston
d7acbe481d vm_page: Break reservations to handle noobj allocations
vm_reserv_reclaim_*() will release pages to the default freepool, not
the direct freepool from which noobj allocations are drawn.  But if both
pools are empty, the noobj allocator variants must break reservations to
make progress.

Reported by:	cy
Reviewed by:	kib (previous version)
Fixes:	b498f71bc5 ("vm_page: Add a new page allocator interface for unnamed pages")
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32592
2021-10-22 09:25:59 -04:00
Mark Johnston
a9d6f1fe0a Remove some remaining references to VM_ALLOC_NOOBJ
Reviewed by:	alc, kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32037
2021-10-19 21:22:56 -04:00
Mark Johnston
b801c79dda vm_fault: Stop specifying VM_ALLOC_ZERO
Now vm_page_alloc() and friends will unconditionally preserve PG_ZERO,
so there is no point in setting this flag.

Eliminate a local variable and add a comment explaining why we
prioritize the allocation when the process is doomed.

No functional change intended.

Reviewed by:	kib, alc
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32036
2021-10-19 21:22:56 -04:00
Mark Johnston
02fb0585e7 vm_page: Drop handling of VM_ALLOC_NOOBJ in vm_page_alloc_contig_domain()
As in vm_page_alloc_domain_after(), unconditionally preserve PG_ZERO.

Implement vm_page_alloc_noobj_contig_domain().

Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32034
2021-10-19 21:22:56 -04:00
Mark Johnston
c40cf9bc62 vm_page: Stop handling VM_ALLOC_NOOBJ in vm_page_alloc_domain_after()
This makes the allocator simpler since it can assume object != NULL.
Also modify the function to unconditionally preserve PG_ZERO, so
VM_ALLOC_ZERO is effectively ignored (and still must be implemented by
the caller for now).

Reviewed by:	alc, kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32033
2021-10-19 21:22:56 -04:00
Mark Johnston
84c3922243 Convert consumers to vm_page_alloc_noobj_contig()
Remove now-unneeded page zeroing.  No functional change intended.

Reviewed by:	alc, hselasky, kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32006
2021-10-19 21:22:56 -04:00
Mark Johnston
92db9f3bb7 Introduce vm_page_alloc_noobj_contig()
This is the same as vm_page_alloc_noobj(), but allocates physically
contiguous runs of memory.  For now it is implemented in terms of
vm_page_alloc_contig(), with the difference that
vm_page_alloc_noobj_contig() implements VM_ALLOC_ZERO by zeroing the
page.

Reviewed by:	alc, kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32005
2021-10-19 21:22:56 -04:00
Mark Johnston
a4667e09e6 Convert vm_page_alloc() callers to use vm_page_alloc_noobj().
Remove page zeroing code from consumers and stop specifying
VM_ALLOC_NOOBJ.  In a few places, also convert an allocation loop to
simply use VM_ALLOC_WAITOK.

Similarly, convert vm_page_alloc_domain() callers.

Note that callers are now responsible for assigning the pindex.

Reviewed by:	alc, hselasky, kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D31986
2021-10-19 21:22:56 -04:00
Mark Johnston
b498f71bc5 vm_page: Add a new page allocator interface for unnamed pages
The diff adds vm_page_alloc_noobj() and vm_page_alloc_noobj_domain().
These mostly correspond to vm_page_alloc() and vm_page_alloc_domain()
when no VM object is specified, with the exception that they handle
VM_ALLOC_ZERO by zeroing the page, rather than by preserving PG_ZERO.

This simplifies callers and will permit simplification of the
vm_page_alloc_domain() definition.

Since the new allocator variant is similar to vm_page_alloc_freelist(),
implement both of them using a common backend allocator function.  No
functional change intended.

Reviewed by:	alc, kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D31985
2021-10-19 21:22:55 -04:00
Mark Johnston
a23e6a1078 vm_page: Move vm_page_alloc_check() to after page allocator definitions
This way all of the vm_page_alloc_*() allocator functions are grouped
together.

MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
2021-10-19 21:22:50 -04:00
Edward Tomasz Napierala
0f559a9f09 Make vmdaemon timeout configurable
Make vmdaemon timeout configurable, so that one can adjust
how often it runs.

Here's a trick: set this to 1, then run 'limits -m 0 sh',
then run whatever you want with 'ktrace -it XXX', and observe
how the working set changes over time.

Reviewed By:	kib
Sponsored By:	EPSRC
Differential Revision:	https://reviews.freebsd.org/D22038
2021-10-17 13:49:29 +01:00
Dawid Gorecki
889b56c8cd setrlimit: Take stack gap into account.
Calling setrlimit with stack gap enabled and with low values of stack
resource limit often caused the program to abort immediately after
exiting the syscall. This happened due to the fact that the resource
limit was calculated assuming that the stack started at sv_usrstack,
while with stack gap enabled the stack is moved by a random number
of bytes.

Save information about stack size in struct vmspace and adjust the
rlim_cur value. If the rlim_cur and stack gap is bigger than rlim_max,
then the value is truncated to rlim_max.

PR: 253208
Reviewed by: kib
Obtained from: Semihalf
Sponsored by: Stormshield
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D31516
2021-10-15 10:21:47 +02:00
Warner Losh
cdccd11b36 forward declare struct thread
sys/sysctl.h moved struct thread forward declaration under #ifdef
_KERNEL and so this header fails when included from userland. Add a
forward declaration here.

Fixes:	     		99eefc727e
Sponsored by:		Netflix
2021-10-11 12:59:39 -06:00
Konstantin Belousov
174aad047e vm_fault: do not trigger OOM too early
Wakeup in vm_waitpfault() does not mean that the thread would get the
page on the next vm_page_alloc() call, other thread might steal the free
page we were waiting for. On the other hand, this wakeup might come much
earlier than just vm_pfault_oom_wait seconds, if the rate of the page
reclamation is high enough.

If wakeups come fast and we loose the allocation race enough times, OOM
could be undeservably triggered much earlier than vm_pfault_oom_attempts
x vm_pfault_oom_wait seconds.  Fix it by not counting the number of sleeps,
but measuring the time to th first allocation failure, and triggering OOM
when it was older than oom_attempts x oom_wait seconds.

Reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D32287
2021-10-08 12:24:46 +03:00
Mitchell Horne
31991a5a45 minidump: De-duplicate is_dumpable()
The function is identical in each minidump implementation, so move it to
vm_phys.c. The only slight exception is powerpc where the function was
public, for use in moea64_scan_pmap().

Reviewed by:	kib, markj, imp (earlier version)
MFC after:	2 weeks
Sponsored by:	Juniper Networks, Inc.
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D31884
2021-09-29 16:41:52 -03:00
Gleb Smirnoff
183f8e1e57 Externalize nsw_cluster_max and initialize it early.
GEOM_ELI needs to know the value, cause it will soon have special
memory handling for IO operations associated with swap.

Move initialization to swap_pager_init(), which is executed at
SI_SUB_VM, unlike swap_pager_swap_init(), which would be executed
only when a swap is configured. GEOM_ELI might need the value at
SI_SUB_DRIVERS, when disks are tasted by GEOM.

Reviewed by:		kib
Differential Revision:	https://reviews.freebsd.org/D24400
2021-09-28 11:23:52 -07:00
Gleb Smirnoff
c6213beff4 Add flag BIO_SWAP to mark IOs that are associated with swap.
Submitted by:		jtl
Reviewed by:		kib
Differential Revision:	https://reviews.freebsd.org/D24400
2021-09-28 11:23:51 -07:00
Konstantin Belousov
bd3a668087 vm_page_startup: correct calculation of the starting page
Also avoid unneded calculations when phys segment end is the phys_avail[]
start.

Submitted by:	alc
Reviewed by:	markj
MFC after:	1 week
Fixes:	181bfb42fd
Differential revision:	https://reviews.freebsd.org/D32009
2021-09-19 21:27:55 +03:00
Mark Johnston
d6e77cda9b uma: Show the count of free slabs in each per-domain keg's sysctl tree
This is useful for measuring the number of pages that could be freed
from a NOFREE zone under memory pressure.

MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
2021-09-17 14:19:05 -04:00
Konstantin Belousov
181bfb42fd vm_phys: do not ignore phys_avail[] segments that do not fit completely into vm_phys segments
If phys_avail[] segment only intersect with some vm_phys segment, add
pages from it to the free list that belong to the given vm_phys_seg,
instead of dropping them.

The vm_phys segments are generally result of subdivision of phys_avail
segments, for instance DMA32 or LOWMEM boundaries split them. On
amd64, after UEFI in-place kernel activation (copy_staging disable)
was enabled, we typically have a large phys_avail[] segment below 4G
which crosses LOWMEM (1M) boundary. With the current way of requiring
phys_avail[] fully fit into vm_phys_seg, this memory was ignored.

Reported by:	madpilot
Reviewed by:	markj
Discussed with:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D31958
2021-09-16 20:01:19 +03:00
Mark Johnston
686aa9287c swap_pager: Handle large swap_pager_reserve() requests
This interface is used solely by md(4) when the MD_RESERVE flag is
specified, as in `mdconfig -a -t swap -s 1G -o reserve`.  It
pre-allocates swap blocks for the entire object.

The number of blocks to be reserved is specified as a vm_size_t, but
swp_pager_getswapspace() can allocate at most INT_MAX blocks.  vm_size_t
also seems like the incorrect type to use here it refers only to the
size of the VM object, not the size of a mapping.  So:
- change the type of "size" in swap_pager_reserve() to vm_pindex_t, and
- clamp the requested number of blocks for a single
  swp_pager_getswapspace() call to INT_MAX.

Reported by:	syzkaller
Reviewed by:	dougm, alc, kib
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D31875
2021-09-07 14:04:50 -04:00
Bjoern A. Zeeb
eccb516db8 vm: use __func__ for the correct function name
In fee2a2fa39 the KASSERTs in
vm_page_unwire_noq() changed from "vm_page_unwire" to "vm_page_unref".
While the former no longer was part of that function the latter does
not exist as a function and is highly confusing when hit when using
tools to lookup the functions and not doing a full-text search.
Use %s __func__ for printing the function name, as that will do the
right thing as code moves around and functions get renamed.

Hit:	while debugging a wired page leak with linuxkpi/iwlwifi
Sponsored by:	The FreeBSD Foundation
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D31635
2021-08-22 17:43:12 +00:00