vm_page_free_toq() to account for recent changes that allow
vm_page_free_toq() to be called on some pages without the page queues lock
being held, specifically, pages that are not contained in a vm object and
not a member of a page queue. (Examples of such pages include page table
pages, pv entry pages, and uma small alloc pages.)
is actually being added to the hold queue, not the free queue. At the same
time, avoid unnecessary tests to wake up threads waiting for free memory
and the idle thread that zeroes free pages. (These tests will be performed
later when the page finally moves from the hold queue to the free queue.)
boot by MD code to indicated detected alignment preference. Rather than
cache alignment being encoded in UMA consumers by defining a global
alignment value of (16 - 1) in UMA_ALIGN_CACHE, UMA_ALIGN_CACHE is now
a special value (-1) that causes UMA to look at registered alignment. If
no preferred alignment has been selected by MD code, a default alignment
of (16 - 1) will be used.
Currently, no hardware platforms specify alignment; architecture
maintainers will need to modify MD startup code to specify an alignment
if desired. This must occur before initialization of UMA so that all UMA
zones pick up the requested alignment.
Reviewed by: jeff, alc
Submitted by: attilio
- Restore support for fetching swap information from crash dumps via
kvm_get_swapinfo(3) to fix pstat -T/-s on crash dumps.
Reviewed by: arch@, phk
MFC after: 1 week
zone. Cluster allocations fail when this happens. Also processes that may have
blocked on cluster allocations will never be woken up. Thanks to rwatson for
an overview of the issue and pointers to the mbuma paper and his tool to dump
out UMA zones.
Reviewed by: andre@
maxpages on a zone is woken up, with the rest never being woken up as
a result of the ZFLAG_FULL flag being cleared. Wakeup all such blocked
procsses instead. This change introduces a thundering herd, but since
this should be relatively infrequent, optimizing this (by introducing
a count of blocked processes, for example) may be premature.
Reviewd by: ups@
setrunqueue() was mostly empty. The few asserts and thread state
setting were moved to the individual schedulers. sched_add() was
chosen to displace it for naming consistency reasons.
- Remove adjustrunqueue, it was 4 lines of code that was ifdef'd to be
different on all three schedulers where it was only called in one place
each.
- Remove the long ifdef'd out remrunqueue code.
- Remove the now redundant ts_state. Inspect the thread state directly.
- Don't set TSF_* flags from kern_switch.c, we were only doing this to
support a feature in one scheduler.
- Change sched_choose() to return a thread rather than a td_sched. Also,
rely on the schedulers to return the idlethread. This simplifies the
logic in choosethread(). Aside from the run queue links kern_switch.c
mostly does not care about the contents of td_sched.
Discussed with: julian
- Move the idle thread loop into the per scheduler area. ULE wants to
do something different from the other schedulers.
Suggested by: jhb
Tested on: x86/amd64 sched_{4BSD, ULE, CORE}.
allocations were made using improper flags in interrupt context.
Replace with a simple WITNESS warning call. This restores the
invariant that M_WAITOK allocations will always succeed or die
horribly trying, which is relied on by many UMA consumers.
MFC after: 3 weeks
Discussed with: jhb
- Add a printf in swp_pager_meta_build() to warn if the swapzone becomes
exhausted so that there's at least a warning before a box that runs out
of swapzone space before running out of swap space deadlocks.
MFC after: 1 week
Reviwed by: alc
Make part of John Birrell's KSE patch permanent..
Specifically, remove:
Any reference of the ksegrp structure. This feature was
never fully utilised and made things overly complicated.
All code in the scheduler that tried to make threaded programs
fair to unthreaded programs. Libpthread processes will already
do this to some extent and libthr processes already disable it.
Also:
Since this makes such a big change to the scheduler(s), take the opportunity
to rename some structures and elements that had to be moved anyhow.
This makes the code a lot more readable.
The ULE scheduler compiles again but I have no idea if it works.
The 4bsd scheduler still reqires a little cleaning and some functions that now do
ALMOST nothing will go away, but I thought I'd do that as a separate commit.
Tested by David Xu, and Dan Eischen using libthr and libpthread.
specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.
This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA
it introduced a check after the call to file system's get pages method
that assumes that the get pages method does not change the array of pages
that is passed to it. In the case of vnode_pager_generic_getpages(),
this assumption has been incorrect. The contents of the array of pages
may be shifted by vnode_pager_generic_getpages(). Likely, the problem
has been hidden by vnode_pager_haspage() limiting the set of pages that
are passed to vnode_pager_generic_getpages() such that a shift never
occurs.
The fix implemented herein is to adjust the pointer to the array of pages
rather than shifting the pages within the array.
MFC after: 3 weeks
Fix suggested by: tegge
an error returned by VOP_BMAP() and a hole in the file.
Change the callers to vnode_pager_addr() such that they return
VM_PAGER_ERROR when VOP_BMAP fails instead of a zero-filled page.
Reviewed by: tegge
MFC after: 3 weeks
size aligned requiring heavy usage of vm_page_alloc_contig
This change makes vm_page_alloc_contig SMP safe
Approved by: scottl (acting as backup for mentor rwatson)
vnode_pager_generic_getpages(): (1) that VOP_BMAP() is unsupported by the
underlying file system and (2) an error in performing the VOP_BMAP().
Previously, vnode_pager_generic_getpages() assumed that all errors were
of the first type. If, in fact, the error was of the second type, the
likely outcome was for the process to become permanently blocked on a busy
page.
MFC after: 3 weeks
Reviewed by: tegge
inlined and a procedure call is made in the rare case, i.e., when it is
necessary to sleep. In this case, inlining the test actually makes the
kernel smaller.
page queues-synchronized flag. Reduce the scope of the page queues lock in
vm_fault() accordingly.
Move vm_fault()'s call to vm_object_set_writeable_dirty() outside of the
scope of the page queues lock. Reviewed by: tegge
Additionally, eliminate an unnecessary dereference in computing the
argument that is passed to vm_object_set_writeable_dirty().
synchronized by the lock on the object containing the page.
Transition PG_WANTED and PG_SWAPINPROG to use the new field,
eliminating the need for holding the page queues lock when setting
or clearing these flags. Rename PG_WANTED and PG_SWAPINPROG to
VPO_WANTED and VPO_SWAPINPROG, respectively.
Eliminate the assertion that the page queues lock is held in
vm_page_io_finish().
Eliminate the acquisition and release of the page queues lock
around calls to vm_page_io_finish() in kern_sendfile() and
vfs_unbusy_pages().
Originally, I had adopted sparc64's name, pmap_clear_write(), for the
function that is now pmap_remove_write(). However, this function is more
like pmap_remove_all() than like pmap_clear_modify() or
pmap_clear_reference(), hence, the name change.
The higher-level rationale behind this change is described in
src/sys/amd64/amd64/pmap.c revision 1.567. The short version is that I'm
trying to clean up and fix our support for execute access.
Reviewed by: marcel@ (ia64)
system's machine-dependent and machine-independent layers. Once
pmap_clear_write() is implemented on all of our supported
architectures, I intend to replace all calls to pmap_page_protect() by
calls to pmap_clear_write(). Why? Both the use and implementation of
pmap_page_protect() in our virtual memory system has subtle errors,
specifically, the management of execute permission is broken on some
architectures. The "prot" argument to pmap_page_protect() should
behave differently from the "prot" argument to other pmap functions.
Instead of meaning, "give the specified access rights to all of the
physical page's mappings," it means "don't take away the specified
access rights from all of the physical page's mappings, but do take
away the ones that aren't specified." However, owing to our i386
legacy, i.e., no support for no-execute rights, all but one invocation
of pmap_page_protect() specifies VM_PROT_READ only, when the intent
is, in fact, to remove only write permission. Consequently, a
faithful implementation of pmap_page_protect(), e.g., ia64, would
remove execute permission as well as write permission. On the other
hand, some architectures that support execute permission have
basically ignored whether or not VM_PROT_EXECUTE is passed to
pmap_page_protect(), e.g., amd64 and sparc64. This change represents
the first step in replacing pmap_page_protect() by the less subtle
pmap_clear_write() that is already implemented on amd64, i386, and
sparc64.
Discussed with: grehan@ and marcel@
pointer: When vm_object_deallocate() sleeps because of a non-zero
paging in progress count on either object or object's shadow,
vm_object_deallocate() must ensure that object is still the shadow's
backing object when it reawakens. In fact, object may have been
deallocated while vm_object_deallocate() slept. If so, reacquiring
the lock on object can lead to a deadlock.
Submitted by: ups@
MFC after: 3 weeks
libmemstat(3) is used by vmstat (and friends) to produce more accurate
and more detailed statistics information in a machine-readable way,
and vmstat continues to provide the same text-based front-end.
This change should not be MFC'd.
vm_page_startup(). As a result, we now only lookup the tunable once
instead of looking it up once for every physical page of memory in the
system. This cuts out about a 1 second or so delay in boot on x86
systems. The delay is much larger and more noticable on sun4v apparently.
Reported by: kmacy
MFC after: 1 week
There is a race with the current locking scheme and removing
it should have no measurable performance impact.
This fixes page faults leading to panics in pmap_enter_quick_locked()
on amd64/i386.
Reviewed by: alc,jhb,peter,ps
Found mapped cache page. Specifically, if cnt.v_free_count dips below
cnt.v_free_reserved after p_start has been set to a non-NULL value,
then vm_map_pmap_enter() would break out of the loop and incorrectly
call pmap_enter_object() for the remaining address range. To correct
this error, this revision truncates the address range so that
pmap_enter_object() will not map any cache pages.
In collaboration with: tegge@
Reported by: kris@
These pages are allocated from the direct map, and were not previous
tracked. This included the vm_page_array and the early UMA bootstrap
pages.
Reviewed by: peter
vmspace_exitfree() and vmspace_free() which could result in the same
vmspace being freed twice.
Factor out part of exit1() into new function vmspace_exit(). Attach
to vmspace0 to allow old vmspace to be freed earlier.
Add new function, vmspace_acquire_ref(), for obtaining a vmspace
reference for a vmspace belonging to another process. Avoid changing
vmspace refcount from 0 to 1 since that could also lead to the same
vmspace being freed twice.
Change vmtotal() and swapout_procs() to use vmspace_acquire_ref().
Reviewed by: alc
report this as an allocation failure for the item type. The failure
will be separately recorded with the bucket type. This my eliminate
high mbuf allocation failure counts under some circumstances, which
can be alarming in appearance, but not actually a problem in
practice.
MFC after: 2 weeks
Reported by: ps, Peter J. Blok <pblok at bsd4all dot org>,
OxY <oxy at field dot hu>,
Gabor MICSKO <gmicskoa at szintezis dot hu>
via the debug.minidump sysctl and tunable.
Traditional dumps store all physical memory. This was once a good thing
when machines had a maximum of 64M of ram and 1GB of kvm. These days,
machines often have many gigabytes of ram and a smaller amount of kvm.
libkvm+kgdb don't have a way to access physical ram that is not mapped
into kvm at the time of the crash dump, so the extra ram being dumped
is mostly wasted.
Minidumps invert the process. Instead of dumping physical memory in
in order to guarantee that all of kvm's backing is dumped, minidumps
instead dump only memory that is actively mapped into kvm.
amd64 has a direct map region that things like UMA use. Obviously we
cannot dump all of the direct map region because that is effectively
an old style all-physical-memory dump. Instead, introduce a bitmap
and two helper routines (dump_add_page(pa) and dump_drop_page(pa)) that
allow certain critical direct map pages to be included in the dump.
uma_machdep.c's allocator is the intended consumer.
Dumps are a custom format. At the very beginning of the file is a header,
then a copy of the message buffer, then the bitmap of pages present in
the dump, then the final level of the kvm page table trees (2MB mappings
are expanded into a 4K page mappings), then the sparse physical pages
according to the bitmap. libkvm can now conveniently access the kvm
page table entries.
Booting my test 8GB machine, forcing it into ddb and forcing a dump
leads to a 48MB minidump. While this is a best case, I expect minidumps
to be in the 100MB-500MB range. Obviously, never larger than physical
memory of course.
minidumps are on by default. It would want be necessary to turn them off
if it was necessary to debug corrupt kernel page table management as that
would mess up minidumps as well.
Both minidumps and regular dumps are supported on the same machine.
if the specified priority is zero. This avoids a race where the calling
thread could read a snapshot of it's current priority, then a different
thread could change the first thread's priority, then the original thread
would call sched_prio() inside msleep() undoing the change made by the
second thread. I used a priority of zero as no thread that calls msleep()
or tsleep() should be specifying a priority of zero anyway.
The various places that passed 'curthread->td_priority' or some variant
as the priority now pass 0.
Kernel changes:
Inform hwpmc of executable objects brought into the system by
kldload() and mmap(), and of their removal by kldunload() and
munmap(). A helper function linker_hwpmc_list_objects() has been
added to "sys/kern/kern_linker.c" and is used by hwpmc to retrieve
the list of currently loaded kernel modules.
The unused `MAPPINGCHANGE' event has been deprecated in favour
of separate `MAP_IN' and `MAP_OUT' events; this change reduces
space wastage in the log.
Bump the hwpmc's ABI version to "2.0.00". Teach hwpmc(4) to
handle the map change callbacks.
Change the default per-cpu sample buffer size to hold
32 samples (up from 16).
Increment __FreeBSD_version.
libpmc(3) changes:
Update libpmc(3) to deal with the new events in the log file; bring
the pmclog(3) manual page in sync with the code.
pmcstat(8) changes:
Introduce new options to pmcstat(8): "-r" (root fs path), "-M"
(mapfile name), "-q"/"-v" (verbosity control). Option "-k" now
takes a kernel directory as its argument but will also work with
the older invocation syntax.
Rework string handling in pmcstat(8) to use an opaque type for
interned strings. Clean up ELF parsing code and add support for
tracking dynamic object mappings reported by a v2.0.00 hwpmc(4).
Report statistics at the end of a log conversion run depending
on the requested verbosity level.
Reviewed by: jhb, dds (kernel parts of an earlier patch)
Tested by: gallatin (earlier patch)
be called without any vnode locks held. Remove calls to vn_start_write() and
vn_finished_write() in vnode_pager_putpages() and add these calls before the
vnode lock is obtained to most of the callers that don't already have them.
object that requires Giant in vm_object_deallocate(). This is somewhat
hairy in that if we can't obtain Giant directly, we have to drop the
object lock, then lock Giant, then relock the object lock and verify that
we still need Giant. If we don't (because the object changed to OBJT_DEAD
for example), then we drop Giant before continuing.
Reviewed by: alc
Tested by: kris
and it has not plenty of free pages it tries to free pages in the cache queue.
Unfortunately freeing a cached page requires the locking of the object that
owns the page. However in the context of allocating pages we may not be able
to lock the object and thus can only TRY to lock the object. If the locking try
fails the cache page can not be freed and is activated to move it out of the way
so that we may try to free other cache pages.
If all pages in the cache belong to objects that are currently locked the
cache queue can be emptied without freeing a single page. This scenario caused
two problems:
1) vm_page_alloc always failed allocation when it tried freeing pages from
the cache queue and failed to do so. However if there are more than
cnt.v_interrupt_free_min pages on the free list it should return pages
when requested with priority VM_ALLOC_SYSTEM. Failure to do so can cause
resource exhaustion deadlocks.
2) Threads than need to allocate pages spend a lot of time cleaning up the
page queue without really getting anything done while the pagedaemon
needs to work overtime to refill the cache.
This change fixes the first problem. (1)
Reviewed by: tegge@
lock also protects this flag so it is not necessary.
- Don't rely on v_mount to detect whether or not we've been recycled, use
the more appropriate VI_DOOMED instead.
Sponsored by: Isilon Systems, Inc.
MFC After: 1 week
The former type, size_t, was causing truncation to 32 bits on i386,
which immediately led to undersizing of VM objects backed by
files >4GB. In particular, sendfile(2) was broken for such files.
PR: kern/92243
MFC after: 5 days
