because the queue itself serves no purpose. When a held page is freed,
inserting the page into the hold queue has the side effect of setting the
page's "queue" field to PQ_HOLD. Later, when the page is unheld, it will
be freed because the "queue" field is PQ_HOLD. In other words, PQ_HOLD is
used as a flag, not a queue. So, this change replaces it with a flag.
To accomodate the new page flag, make the page's "flags" field wider and
"oflags" field narrower.
Reviewed by: kib
forked. Otherwise, pagedaemon might reclaim the page without saving
its content into the swap file, resulting in the valid content
replaced by zeroes.
Reported and tested by: pho
Reviewed and comment update by: alc
MFC after: 1 week
In particular, do not lock Giant conditionally when calling into the
filesystem module, remove the VFS_LOCK_GIANT() and related
macros. Stop handling buffers belonging to non-mpsafe filesystems.
The VFS_VERSION is bumped to indicate the interface change which does
not result in the interface signatures changes.
Conducted and reviewed by: attilio
Tested by: pho
vm_page_sleep(). vm_page_sleep() is no longer called with this lock
held.
Eliminate assertions that the page queues lock is NOT held. These
assertions won't translate well to having distinct locks on the active
and inactive page queues, and they really aren't that useful.
MFC after: 3 weeks
Update some of the comments. In particular, use "sleep" in preference to
"block" where appropriate.
Eliminate some unnecessary casts.
Make a few whitespace changes for consistency.
Reviewed by: kib
MFC after: 3 days
If you have a binary on a filesystem which is also mounted over by
nullfs, you could execute the binary from the lower filesystem, or
from the nullfs mount. When executed from lower filesystem, the lower
vnode gets VV_TEXT flag set, and the file cannot be modified while the
binary is active. But, if executed as the nullfs alias, only the
nullfs vnode gets VV_TEXT set, and you still can open the lower vnode
for write.
Add a set of VOPs for the VV_TEXT query, set and clear operations,
which are correctly bypassed to lower vnode.
Tested by: pho (previous version)
MFC after: 2 weeks
queues lock is acquired before the page lock is released, there is no
guarantee that the page will still be in that same page queue when
vm_page_requeue() is called.
Reported by: pho
In collaboration with: kib
MFC after: 3 days
is performed on the vnode mapping which is wired in other address space.
While there, explicitely assert that the page is unwired and zero the
wire_count instead of substract. The condition is rechecked later in
vm_page_free(_toq) already.
Reported and tested by: zont
Reviewed by: alc (previous version)
MFC after: 1 week
There are two consumers of vslock(9): sysctl code and drm driver. These
consumers are using locked memory as transient memory, it doesn't belong
to a process's memory.
Suggested by: avg
Reviewed by: alc
Approved by: kib (mentor)
MFC after: 2 weeks
tick until the situation is resolved (if ever), just print a single
message when running out and another when space becomes available.
- When adding more swap, warn if the total amount exceeds half the
theoretical maximum we can handle.
PROT_EXEC if prot is non-zero, process is 32bit and
kern.elf32.i386_read_exec syscal is enabled. This workaround is needed
for old i386 a.out binaries, where dynamic linker did not specified
PROT_EXEC for mapping of the text.
The kern.elf32.i386_read_exec MIB name looks weird for a.out binaries,
but I reused the existing knob which already has the needed semantic.
MFC after: 1 week
mappings for a.out binaries. Apparently, a.out ld.so from FreeBSD
1.1.5.1 can issue such requests.
Reported and tested by: Dan Plassche <dplassche@gmail.com>
MFC after: 1 week
network file systems (not only NFS proper). Short reads cause pages
other then the requested one, which were not filled by read response,
to stay invalid.
Change the vm_page_readahead_finish() interface to not take the error
code, but instead to make a decision to free or to (de)activate the
page only by its validity. As result, not requested invalid pages are
freed even if the read RPC indicated success.
Noted and reviewed by: alc
MFC after: 1 week
ago, sleeping on busy pages in vm_pageout_launder() made sense. The call
to vm_pageout_flush() specified asynchronous I/O and sleeping on busy pages
blocked vm_pageout_launder() until the flush had completed. However, in
CVS revision 1.35 of vm/vm_contig.c, the call to vm_pageout_flush() was
changed to request synchronous I/O, but the sleep on busy pages was not
removed.
to pull vm_param.h was removed. Other big dependency of vm_page.h on
vm_param.h are PA_LOCK* definitions, which are only needed for
in-kernel code, because modules use KBI-safe functions to lock the
pages.
Stop including vm_param.h into vm_page.h. Include vm_param.h
explicitely for the kernel code which needs it.
Suggested and reviewed by: alc
MFC after: 2 weeks
vm_page oflags by providing helper function
vm_page_readahead_finish(), which handles completed reads for pages
with indexes other then the requested one, for VOP_GETPAGES().
Reviewed by: alc
MFC after: 1 week
them alone.
Process the act_count updates for the held pages in the vm_pageout
loop over the inactive queue, instead of refusing to do anything with
such page.
Clarify the intent of the addl_page_shortage counter and change its
use for pages which are not processed in the loop according to the
description.
Reviewed by: alc
MFC after: 2 weeks
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
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
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
