an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls
vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified()
could return FALSE without acquiring the page queues lock because the page
is not (currently) writeable, and the caller to pmap_is_modified() might
believe that the page's dirty field is clear because it has not seen the
effect of the vm_page_dirty() call.
When I pushed down the page queues lock into pmap_is_modified(), I
overlooked one place where this ordering dependence is violated:
pmap_enter(). In a rare situation pmap_enter() can be called to replace a
dirty mapping to one page with a mapping to another page. (I say rare
because replacements generally occur as a result of a copy-on-write fault,
and so the old page is not dirty.) This change delays clearing PG_WRITEABLE
until after vm_page_dirty() has been called.
Fixing the ordering dependency also makes it easy to introduce a small
optimization: When pmap_enter() used to replace a mapping to one page with a
mapping to another page, it freed the pv entry for the first mapping and
later called the pv entry allocator for the new mapping. Now, pmap_enter()
attempts to recycle the old pv entry, saving two calls to the pv entry
allocator.
There is no point in setting PG_WRITEABLE on unmanaged pages, so don't.
Update a comment to reflect this.
Tidy up the variable declarations at the start of pmap_enter().
- Add an integer argument to idle to indicate how likely we are to wake
from idle over the next tick.
- Add a new MD routine, cpu_wake_idle() to wakeup idle threads who are
suspended in cpu specific states. This function can fail and cause the
scheduler to fall back to another mechanism (ipi).
- Implement support for mwait in cpu_idle() on i386/amd64 machines that
support it. mwait is a higher performance way to synchronize cpus
as compared to hlt & ipis.
- Allow selecting the idle routine by name via sysctl machdep.idle. This
replaces machdep.cpu_idle_hlt. Only idle routines supported by the
current machine are permitted.
Although "--" historically has not been required to be recognized for
certain special builtins that do not take options in POSIX, some other
implementations recognize options for them, requiring scripts to use "--" or
avoid operands starting with "-".
Operands starting with "-" can be avoided with eval by prepending a space,
and cannot occur with break, continue, exit, return and shift as they only
take numbers, nor with times as it does not take operands. With . and exec,
avoiding "-" is not so easy as it may require reimplementing the PATH
search; therefore the current proposal for POSIX is to require recognition
of "--" for them.
We continue to accept other strings starting with "-" as operands to . and
exec, and also "--" if it is alone to . (which would otherwise be invalid
anyway).
ta_func may free the task structure, so no references to its members
are valid after the handler has been called. Using a per-queue member
and having waits longer than strictly necessary was suggested by jhb.
Submitted by: Matthew Fleming <matthew.fleming@isilon.com>
Reviewed by: zml, jhb
o Let OFW_INIT() and OF_init() return status value.
o Provide helper routines for 'compatible' property handling.
o Only compile OF and OFW code, which is relevant in FDT scenario.
o Other minor cosmetics
Reviewed by: imp
Sponsored by: The FreeBSD Foundation
- Fix handling of ^@ when reading an ex command. Don't try to replay
the previous input.
- Fix handling of ^C in insert mode and when reading an ex command.
Repeating an interrupted input could cause a crash and interrupting
ex command input could cause a file corruption.
- Fix a bug which causes crashes in file name completion when a file
name is longer than the screen width.
- When an error occurs in v_txt(), leave the input mode.
PR: bin/21089, bin/136393
Obtained from: NetBSD
- use correct size (512) while reading a gang block
- skip holes while reading child blocks
- advance buffer pointer while reading child blocks
PR: 144214
MFC after: 10 days
will be called automatically by 'timer1clock()'.
Do profiling as often as possible by running it as the same frequency as
'timer1hz'. The statistics clock is run as close to 128Hz as possible.
Pointed out by: mav@
file via NFS. Specifically, to satisfy close-to-open-consistency, the NFS
client always performs at least one RPC on a file during an open(2) to see
if the file has changed. Normally this RPC is an ACCESS or GETATTR RPC
that is forced by flushing a file's attribute cache during nfs_open() and
then requesting new attributes. However, if the file is noticed to be
stale during nfs_open(), the only recourse is to fail the open(2) call
with ESTALE. On the other hand, if the ACCESS or GETATTR RPC is sent
during nfs_lookup(), then the NFS client can fall back to a LOOKUP RPC to
obtain the new file handle in the case that a file has been replaced.
This change causes the NFS client to flush the attribute cache during
nfs_lookup() when validating a name cache hit if the attributes fetched
during nfs_lookup() can be reused in nfs_open(). This allows the client
to open a replaced file via the new file handle the first time that it
notices a replaced file rather than failing with ESTALE in some cases.
Reviewed by: rmacklem, bde
Reviewed by: mohans (older version)
MFC after: 1 week
set but be cleared before the call to sodisconnect(). In this case,
ENOTCONN is returned: suppress this error rather than returning it to
userspace so that close() doesn't report an error improperly.
PR: kern/144061
Reported by: Matt Reimer <mreimer at vpop.net>,
Nikolay Denev <ndenev at gmail.com>,
Mikolaj Golub <to.my.trociny at gmail.com>
MFC after: 3 days
There's a parsing error for fields where addresses are not separated by
space. This is often produced by MS Outlook, eg.:
Cc: <foo@bar.com>,"Mr Foo" <foo@baz.com>
The following line now splits into the right tokens:
Cc: f@b.com,z@y.de, <a@a.de>,<c@c.de>, "foo" <foo>,"bar" <bar>
PR: bin/131861
Submitted by: Pete French <petefrench at ticketswitch.com>
Tested by: Pete French
Reviewed by: mikeh
MFC after: 2 weeks
the jail(8) command. [10:04]
Fix a one-NUL-byte buffer overflow in libopie. [10:05]
Correctly sanity-check a buffer length in nfs mount. [10:06]
Approved by: so (cperciva)
Approved by: re (kensmith)
Security: FreeBSD-SA-10:04.jail
Security: FreeBSD-SA-10:05.opie
Security: FreeBSD-SA-10:06.nfsclient
whole bus (XPT_SCAN_BUS) and a single lun on that bus (XPT_SCAN_LUN).
It's less resource comsumptive than scanning a whole bus when the
caller knows only one target has changes.
Reviewed by: scsi@
Sponsored by: Panasas
MFC after: 1 month
pmap_is_referenced(). Eliminate the corresponding page queues lock
acquisitions from vm_map_pmap_enter() and mincore(), respectively. In
mincore(), this allows some additional cases to complete without ever
acquiring the page queues lock.
Assert that the page is managed in pmap_is_referenced().
On powerpc/aim, push down the page queues lock acquisition from
moea*_is_modified() and moea*_is_referenced() into moea*_query_bit().
Again, this will allow some additional cases to complete without ever
acquiring the page queues lock.
Reorder a few statements in vm_page_dontneed() so that a race can't lead
to an old reference persisting. This scenario is described in detail by a
comment.
Correct a spelling error in vm_page_dontneed().
Assert that the object is locked in vm_page_clear_dirty(), and restrict the
page queues lock assertion to just those cases in which the page is
currently writeable.
Add object locking to vnode_pager_generic_putpages(). This was the one
and only place where vm_page_clear_dirty() was being called without the
object being locked.
Eliminate an unnecessary vm_page_lock() around vnode_pager_setsize()'s call
to vm_page_clear_dirty().
Change vnode_pager_generic_putpages() to the modern-style of function
definition. Also, change the name of one of the parameters to follow
virtual memory system naming conventions.
Reviewed by: kib
