Reviewed by: alc, markj (as part of the larger patch)
Tested by: pho (again, as part of the larger patch)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D13671
for finding aligned free space in the given map. With this change, we
always return KERN_NO_SPACE when we fail to find free space. Whereas,
previously, we might return KERN_INVALID_ADDRESS. Also, with this change,
we explicitly check for address wrap, rather than relying upon the map's
min and max addresses to establish sentinel-like regions.
This refactoring was inspired by the problem that we addressed in r326098.
Reviewed by: kib
Tested by: pho
Discussed with: markj
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D13346
Otherwise the page daemon will not reclaim pages and thus will not
wake threads sleeping in VM_WAIT.
Reported and tested by: pho
Reviewed by: alc, kib
X-MFC with: r327168
Differential Revision: https://reviews.freebsd.org/D13640
Both issues caused the page daemon to erroneously go to sleep when
applications are consuming free pages at a high rate, leaving the
application threads blocked in VM_WAIT.
1) After completing an inactive queue scan, concurrent allocations may
have prevented the page daemon from meeting the v_free_min threshold.
In this case, the page daemon was going to sleep even when the
inactive queue contained plenty of clean pages.
2) pagedaemon_wakeup() may be called without the free queues lock held.
This can lead to a lost wakeup if a call occurs after the page daemon
clears vm_pageout_wanted but before going to sleep.
Fix 1) by ensuring that we start a new inactive queue scan immediately
if v_free_count < v_free_min after a prior scan.
Fix 2) by adding a new subroutine, pagedaemon_wait(), called from
vm_wait() and vm_waitpfault(). It wakes up the page daemon if either
vm_pages_needed or vm_pageout_wanted is false, and atomically sleeps
on v_free_count.
Reported by: jeff
Reviewed by: alc
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D13424
The laundry thread keeps track of the number of inactive queue scans
performed by the page daemon, and was previously using the v_pdwakeups
counter to count them. However, in some cases the inactive queue may
be scanned multiple times after a single wakeup, so it's more accurate
to use a dedicated counter.
Reviewed by: alc, kib (previous version)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D13422
r292392 modified the active queue scan to weigh clean pages differently
from dirty pages when attempting to meet the inactive queue target. When
r306706 was merged into the PQ_LAUNDRY branch, this mechanism was
broken. Fix it by scalaing the correct page shortage variable.
Reviewed by: alc, kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D13423
atomic_set_*() sets a bit in the target memory location, so
atomic_set_int(&uma_reclaim_needed, 0) does not do what it looks like
it does.
PR: 224080
Reviewed by: jeff, kib
Differential Revision: https://reviews.freebsd.org/D13412
Commit r326346 moved domain iterators from physical layer to vm_page one,
but it also removed translation of freelist to flind for
vm_page_alloc_freelist() call. Before it expects VM_FREELIST_ parameter,
but after it expect freelist index.
On small WiFi boxes with few megabytes of RAM, there is only one freelist
VM_FREELIST_LOWMEM (1) and there is no VM_FREELIST_DEFAULT(0) (see file
sys/mips/include/vmparam.h). It results in freelist 1 with flind 0.
At first, this commit renames flind to freelist in vm_page_alloc_freelist
to avoid misunderstanding about input parameters. Then on physical layer it
restores translation for correct handling of freelist parameter.
Reported by: landonf
Reviewed by: jeff
Differential Revision: https://reviews.freebsd.org/D13351
It's theoretically possible for the vnode and object to be disassociated
while locks are dropped around the vget() call, in which case we
shouldn't proceed with laundering.
Noted and reviewed by: kib
MFC after: 1 week
The arena argument to kmem_*() is now only used in an assert. A follow-up
commit will remove the argument altogether before we freeze the API for the
next release.
This replaces the hard limit on kmem size with a soft limit imposed by UMA. When
the soft limit is exceeded we periodically wakeup the UMA reclaim thread to
attempt to shrink KVA. On 32bit architectures this should behave much more
gracefully as we exhaust KVA. On 64bit the limits are likely never hit.
Reviewed by: markj, kib (some objections)
Discussed with: alc
Tested by: pho
Sponsored by: Netflix / Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D13187
blocks in a single call to blist_alloc(). However, when it frees
that space, it previously called blist_free() on each block, one at a
time. With this change, the swap pager identifies ranges of
contiguous blocks to be freed, and calls blist_free() once per
range. In one extreme case, that is described in the review, the time
to perform an munmap(2) was reduced by 55%.
Submitted by: Doug Moore <dougm@rice.edu>
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D12397
This gives a marginal improvement in the vm_page_array initialization
time. Also garbage-collect the now-unused vm_phys_paddr_to_segind().
Reviewed by: alc, kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D13270
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
No functional change intended.
On KERN_NO_SPACE error, as it is returned now, vm_map_find() continues
the loop searching for the suitable range for the requested mapping
with specific alignment. Since the vm_map_findspace() succesfully
finds the same place, the loop never ends.
The errors returned from vm_map_stack() completely repeat the behavior
of vm_map_insert() now, as suggested by Alan.
Reported by: Arto Pekkanen <aksyom@gmail.com>
PR: 223732
Reviewed by: alc, markj
Discussed with: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Differential revision: https://reviews.freebsd.org/D13186
second scan of the address space with find_space = VMFS_ANY_SPACE is
performed. Previously, vm_map_find() released and reacquired the map lock
between the first and second scans. However, there is no compelling
reason to do so. This revision modifies vm_map_find() to retain the map
lock.
Reviewed by: jhb, kib, markj
MFC after: 1 week
X-Differential Revision: https://reviews.freebsd.org/D13155
Some drm2 drivers will set PG_FICTITIOUS in physical pages in order to
satisfy the OBJT_MGTDEVICE object interface, so a scan may encounter
fictitous pages. For now, allow for this possibility; such pages will be
skipped later in the scan since they are wired.
Reported by: avg
Reviewed by: kib
MFC after: 1 week
Mainly focus on files that use BSD 3-Clause license.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
Initially, only tag files that use BSD 4-Clause "Original" license.
RelNotes: yes
Differential Revision: https://reviews.freebsd.org/D13133
hardware sizes.
32bit counters already overflow on approachable virtual memory page
counts, and soon would overflow on the physical pages counts as well.
Bump sizes to 64bit types. Bump __FreeBSD_version.
It is impossible to provide perfect backward ABI compat for this
change. If a program requests an old structure, it can be detected by
size. But if it queries the size first by passing NULL old req
pointer, there is almost nothing we can do to detect the desired ABI.
As a partial solution, check p_osrel of the quering process when
selecting the size to report.
Submitted by: Pawel Biernacki <pawel.biernacki@gmail.com>
Differential revision: https://reviews.freebsd.org/D13018
similar to the kernel memory allocator.
This simplifies NUMA allocation because the domain will be known at wait
time and races between failure and sleeping are eliminated. This also
reduces boilerplate code and simplifies callers.
A wait primitive is supplied for uma zones for similar reasons. This
eliminates some non-specific VM_WAIT calls in favor of more explicit
sleeps that may be satisfied without new pages.
Reviewed by: alc, kib, markj
Tested by: pho
Sponsored by: Netflix, Dell/EMC Isilon
A fictitious page is always wired, so there is no point in trying to
remove one from the page queues.
Completely remove one inaccurate comment from vm_page_free_prep() and
correct another.
Reviewed by: kib, markj
MFC after: 1 week
one call to sysctl(2) from jemalloc startup code. (That also requires
changes to jemalloc, but I plan to push those to upstream first.)
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D12745
This catches some rare mysterious failures at the source. The check
is only performed on architectures which implement direct map, and
only enabled with option DIAGNOSTIC, similar to other costly
consistency checks.
Reviewed by: alc, markj
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Only upgrade it to write mode if we need to clear dirty bits of the
partially valid page after EOF.
Suggested and reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
There is no NO_SWAPPING #ifdef left in the code.
Requested by: alc
Reviewed by: alc, markj
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
Differential revision: https://reviews.freebsd.org/D12663
If filesystem block size is less than the page size, it is possible
that the page-out run contains partially clean pages. E.g., the chunk
of the page might be bdwrite()-ed, or some thread performed bwrite()
on a buffer which references a chunk of the paged out page. As
result, the assertion added in r319975, which checked that all pages
in the run are dirty, does not hold on such filesystems.
One solution is to remove the assert, but it is undesirable, because
we do overwrite the valid on-disk content. I cannot provide a scenario
where such write would corrupt the file data, but I do not like it on
principle. Another, in my opinion proper, solution is to only write
parts of the pages still marked dirty. The patch implements this, it
skips clean blocks and only writes the dirty block runs.
Note that due to clustering, write one page might clean other pages in
the run, so the next write range must be calculated only after the
current range is written out.
More, due to a possible invalidation, and the fact that the object
lock is dropped and reacquired before the checks, it is possible that
the whole page-out pages run appears to consist of only clean pages.
For this reason, it is impossible to assert that there is some work
for the pageout method to do (i.e. assert that there is at least one
dirty page in the run). But such clearing can only occur due to
invalidation, and not due to a parallel write, because we own the
vnode lock exclusive.
Reported by: fsu
In collaboration with: pho
Reviewed by: alc, markj
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
Differential revision: https://reviews.freebsd.org/D12668
pages by vm_object_terminate_pages(). For example, for a "buildworld"
workload, this batching reduces vm_object_terminate_pages()'s average
execution time by 12%. (The total savings were about 11.7 billion
processor cycles.)
Reviewed by: kib
MFC after: 1 week
The variable is modified with the highly contended page free queue lock.
It unnecessarily shares a cacheline with purely read-only fields and is
re-read after the lock is dropped in the page allocation code making the
hold time longer.
Pad the variable just like the others and store the value as found with
the lock held instead of re-reading.
Provides a modest 1%-ish speed up in concurrent page faults.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D12665
the page is already wired or queued. Prior to the elimination of PG_CACHED
pages, vm_page_grab() might have returned a valid, previously PG_CACHED
page, in which case enqueueing the page was necessary. Now, that can't
happen. Moreover, activating the page is a dubious choice, since the page
is not being accessed.
Reviewed by: kib
MFC after: 1 week
