words, every architecture is now auto-sizing the kmem arena. This revision
changes kmeminit() so that the definition of VM_KMEM_SIZE_SCALE becomes
mandatory and the definition of VM_KMEM_SIZE becomes optional.
Replace or eliminate all existing definitions of VM_KMEM_SIZE. With
auto-sizing enabled, VM_KMEM_SIZE effectively became an alternate spelling
for VM_KMEM_SIZE_MIN on most architectures. Use VM_KMEM_SIZE_MIN for
clarity.
Change kmeminit() so that the effect of defining VM_KMEM_SIZE is similar to
that of setting the tunable vm.kmem_size. Whereas the macros
VM_KMEM_SIZE_{MAX,MIN,SCALE} have had the same effect as the tunables
vm.kmem_size_{max,min,scale}, the effects of VM_KMEM_SIZE and vm.kmem_size
have been distinct. In particular, whereas VM_KMEM_SIZE was overridden by
VM_KMEM_SIZE_{MAX,MIN,SCALE} and vm.kmem_size_{max,min,scale}, vm.kmem_size
was not. Remedy this inconsistency. Now, VM_KMEM_SIZE can be used to set
the size of the kmem arena at compile-time without that value being
overridden by auto-sizing.
Update the nearby comments to reflect the kmem submap being replaced by the
kmem arena. Stop duplicating the auto-sizing formula in every machine-
dependent vmparam.h and place it in kmeminit() where auto-sizing takes
place.
Reviewed by: kib (an earlier version)
Sponsored by: EMC / Isilon Storage Division
__mac_set_fd() syscalls are listed earlier.
- Correct typo in syscall name. It should be sched_rr_get_interval,
not sched_rr_getinterval.
Submitted by: David Drysdale <drysdale@google.com>
MFC after: 3 days
allocate memory and so not require sleepable environment. getenv() has
already used on-stack temporary storage, so just use it more rationally.
getenv_string() receives buffer as argument, so don't need another one.
vm_pages. Provide trivial implementation which forwards the load to
_bus_dmamap_load_phys() page by page. Right now all architectures use
bus_dmamap_load_ma_triv().
Tested by: pho (as part of the functional patch)
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
the code executed in the context of debugger, do not be ashamed to
inform loudly about the re-entry. Also, print the backtrace before
obliterating current stack with longjmp, allowing the operator to see
a place which caused the bug.
The change should make it less mysterious debugging the ddb itself.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
Change 221669 by bz@bz_zenith on 2013/02/01 12:26:04
Run the initialization for polling earlier along with INTRs
so that we can put network interface into polling mode by default
if DEVICE_POLLING is compiled in and no interrupts are available.
MFC after: 3 days
Sponsored by: DARPA/AFRL
When safety requirements are met, it allows to avoid passing I/O requests
to GEOM g_up/g_down thread, executing them directly in the caller context.
That allows to avoid CPU bottlenecks in g_up/g_down threads, plus avoid
several context switches per I/O.
The defined now safety requirements are:
- caller should not hold any locks and should be reenterable;
- callee should not depend on GEOM dual-threaded concurency semantics;
- on the way down, if request is unmapped while callee doesn't support it,
the context should be sleepable;
- kernel thread stack usage should be below 50%.
To keep compatibility with GEOM classes not meeting above requirements
new provider and consumer flags added:
- G_CF_DIRECT_SEND -- consumer code meets caller requirements (request);
- G_CF_DIRECT_RECEIVE -- consumer code meets callee requirements (done);
- G_PF_DIRECT_SEND -- provider code meets caller requirements (done);
- G_PF_DIRECT_RECEIVE -- provider code meets callee requirements (request).
Capable GEOM class can set them, allowing direct dispatch in cases where
it is safe. If any of requirements are not met, request is queued to
g_up or g_down thread same as before.
Such GEOM classes were reviewed and updated to support direct dispatch:
CONCAT, DEV, DISK, GATE, MD, MIRROR, MULTIPATH, NOP, PART, RAID, STRIPE,
VFS, ZERO, ZFS::VDEV, ZFS::ZVOL, all classes based on g_slice KPI (LABEL,
MAP, FLASHMAP, etc).
To declare direct completion capability disk(9) KPI got new flag equivalent
to G_PF_DIRECT_SEND -- DISKFLAG_DIRECT_COMPLETION. da(4) and ada(4) disk
drivers got it set now thanks to earlier CAM locking work.
This change more then twice increases peak block storage performance on
systems with manu CPUs, together with earlier CAM locking changes reaching
more then 1 million IOPS (512 byte raw reads from 16 SATA SSDs on 4 HBAs to
256 user-level threads).
Sponsored by: iXsystems, Inc.
MFC after: 2 months
user. Kqueue now saves the ucred of the allocating thread, to
correctly decrement the counter on close.
Under some specific and not real-world use scenario for kqueue, it is
possible for the kqueues to consume memory proportional to the square
of the number of the filedescriptors available to the process. Limit
allows administrator to prevent the abuse.
This is kernel-mode side of the change, with the user-mode enabling
commit following.
Reported and tested by: pho
Discussed with: jmg
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Restore BIO_UNMAPPED and BIO_TRANSIENT_MAPPING in biodonne() when unmapping
temporary mapped buffer. That fixes double unmap if biodone() called twice
for the same BIO (but with different done methods).
Move mapping removal before calling bio_done() method. I believe that it is
very wrong to do anything to BIO after reporting completion. kib@ thinks
it was done for some forgotten now case when bio_done() method needed mapped
buffer. But 1) if BIO was sent as unmapped, then IMO done() should be called
in the same way; 2) IMO there is no guatantee that buffer will be mapped at
this point at all, for example, if all underlying stack supports unmapped
I/O, so bio_done() handler can not expect that.
- Take BIO lock in biodone() only when there is no completion callback set
and so we should wake up thread waiting in biowait().
- Remove msleep() timeout from biowait(). It was added 11 years ago, when
there was no locks used, and it should not be needed any more.
Move tq_enqueue() call out of the queue lock for known handlers (actually
I have found no others in the base system). This reduces queue lock hold
time and congestion spinning under active multithreaded enqueuing.
Introduce new function devstat_end_transaction_bio_bt(), adding new argument
to specify present time. Use this function to move binuptime() out of lock,
substantially reducing lock congestion when slow timecounter is used.
images compiled on the world with higher major version number than the
high version number of the booted kernel. Default to disable.
Sponsored by: The FreeBSD Foundation
Discussed with: bapt
MFC after: 1 week
devfs_iosize_max_clamp sysctl, which allows/disables SSIZE_MAX-sized
i/o requests on the devfs files.
Sponsored by: The FreeBSD Foundation
Reminded by: Dmitry Sivachenko <trtrmitya@gmail.com>
MFC after: 1 week
Refactor of /dev/random device. Main points include:
* Userland seeding is no longer used. This auto-seeds at boot time
on PC/Desktop setups; this may need some tweeking and intelligence
from those folks setting up embedded boxes, but the work is believed
to be minimal.
* An entropy cache is written to /entropy (even during installation)
and the kernel uses this at next boot.
* An entropy file written to /boot/entropy can be loaded by loader(8)
* Hardware sources such as rdrand are fed into Yarrow, and are no
longer available raw.
------------------------------------------------------------------------
r256240 | des | 2013-10-09 21:14:16 +0100 (Wed, 09 Oct 2013) | 4 lines
Add a RANDOM_RWFILE option and hide the entropy cache code behind it.
Rename YARROW_RNG and FORTUNA_RNG to RANDOM_YARROW and RANDOM_FORTUNA.
Add the RANDOM_* options to LINT.
------------------------------------------------------------------------
r256239 | des | 2013-10-09 21:12:59 +0100 (Wed, 09 Oct 2013) | 2 lines
Define RANDOM_PURE_RNDTEST for rndtest(4).
------------------------------------------------------------------------
r256204 | des | 2013-10-09 18:51:38 +0100 (Wed, 09 Oct 2013) | 2 lines
staticize struct random_hardware_source
------------------------------------------------------------------------
r256203 | markm | 2013-10-09 18:50:36 +0100 (Wed, 09 Oct 2013) | 2 lines
Wrap some policy-rich code in 'if NOTYET' until we can thresh out
what it really needs to do.
------------------------------------------------------------------------
r256184 | des | 2013-10-09 10:13:12 +0100 (Wed, 09 Oct 2013) | 2 lines
Re-add /dev/urandom for compatibility purposes.
------------------------------------------------------------------------
r256182 | des | 2013-10-09 10:11:14 +0100 (Wed, 09 Oct 2013) | 3 lines
Add missing include guards and move the existing ones out of the
implementation namespace.
------------------------------------------------------------------------
r256168 | markm | 2013-10-08 23:14:07 +0100 (Tue, 08 Oct 2013) | 10 lines
Fix some just-noticed problems:
o Allow this to work with "nodevice random" by fixing where the
MALLOC pool is defined.
o Fix the explicit reseed code. This was correct as submitted, but
in the project branch doesn't need to set the "seeded" bit as this
is done correctly in the "unblock" function.
o Remove some debug ifdeffing.
o Adjust comments.
------------------------------------------------------------------------
r256159 | markm | 2013-10-08 19:48:11 +0100 (Tue, 08 Oct 2013) | 6 lines
Time to eat crow for me.
I replaced the sx_* locks that Arthur used with regular mutexes;
this turned out the be the wrong thing to do as the locks need to
be sleepable. Revert this folly.
# Submitted by: Arthur Mesh <arthurmesh@gmail.com> (In original diff)
------------------------------------------------------------------------
r256138 | des | 2013-10-08 12:05:26 +0100 (Tue, 08 Oct 2013) | 10 lines
Add YARROW_RNG and FORTUNA_RNG to sys/conf/options.
Add a SYSINIT that forces a reseed during proc0 setup, which happens
fairly late in the boot process.
Add a RANDOM_DEBUG option which enables some debugging printf()s.
Add a new RANDOM_ATTACH entropy source which harvests entropy from the
get_cyclecount() delta across each call to a device attach method.
------------------------------------------------------------------------
r256135 | markm | 2013-10-08 07:54:52 +0100 (Tue, 08 Oct 2013) | 8 lines
Debugging. My attempt at EVENTHANDLER(multiuser) was a failure; use
EVENTHANDLER(mountroot) instead.
This means we can't count on /var being present, so something will
need to be done about harvesting /var/db/entropy/... .
Some policy now needs to be sorted out, and a pre-sync cache needs
to be written, but apart from that we are now ready to go.
Over to review.
------------------------------------------------------------------------
r256094 | markm | 2013-10-06 23:45:02 +0100 (Sun, 06 Oct 2013) | 8 lines
Snapshot.
Looking pretty good; this mostly works now. New code includes:
* Read cached entropy at startup, both from files and from loader(8)
preloaded entropy. Failures are soft, but announced. Untested.
* Use EVENTHANDLER to do above just before we go multiuser. Untested.
------------------------------------------------------------------------
r256088 | markm | 2013-10-06 14:01:42 +0100 (Sun, 06 Oct 2013) | 2 lines
Fix up the man page for random(4). This mainly removes no-longer-relevant
details about HW RNGs, reseeding explicitly and user-supplied
entropy.
------------------------------------------------------------------------
r256087 | markm | 2013-10-06 13:43:42 +0100 (Sun, 06 Oct 2013) | 6 lines
As userland writing to /dev/random is no more, remove the "better
than nothing" bootstrap mode.
Add SWI harvesting to the mix.
My box seeds Yarrow by itself in a few seconds! YMMV; more to follow.
------------------------------------------------------------------------
r256086 | markm | 2013-10-06 13:40:32 +0100 (Sun, 06 Oct 2013) | 11 lines
Debug run. This now works, except that the "live" sources haven't
been tested. With all sources turned on, this unlocks itself in
a couple of seconds! That is no my box, and there is no guarantee
that this will be the case everywhere.
* Cut debug prints.
* Use the same locks/mutexes all the way through.
* Be a tad more conservative about entropy estimates.
------------------------------------------------------------------------
r256084 | markm | 2013-10-06 13:35:29 +0100 (Sun, 06 Oct 2013) | 5 lines
Don't use the "real" assembler mnemonics; older compilers may not
understand them (like when building CURRENT on 9.x).
# Submitted by: Konstantin Belousov <kostikbel@gmail.com>
------------------------------------------------------------------------
r256081 | markm | 2013-10-06 10:55:28 +0100 (Sun, 06 Oct 2013) | 12 lines
SNAPSHOT.
Simplify the malloc pools; We only need one for this device.
Simplify the harvest queue.
Marginally improve the entropy pool hashing, making it a bit faster
in the process.
Connect up the hardware "live" source harvesting. This is simplistic
for now, and will need to be made rate-adaptive.
All of the above passes a compile test but needs to be debugged.
------------------------------------------------------------------------
r256042 | markm | 2013-10-04 07:55:06 +0100 (Fri, 04 Oct 2013) | 25 lines
Snapshot. This passes the build test, but has not yet been finished or debugged.
Contains:
* Refactor the hardware RNG CPU instruction sources to feed into
the software mixer. This is unfinished. The actual harvesting needs
to be sorted out. Modified by me (see below).
* Remove 'frac' parameter from random_harvest(). This was never
used and adds extra code for no good reason.
* Remove device write entropy harvesting. This provided a weak
attack vector, was not very good at bootstrapping the device. To
follow will be a replacement explicit reseed knob.
* Separate out all the RANDOM_PURE sources into separate harvest
entities. This adds some secuity in the case where more than one
is present.
* Review all the code and fix anything obviously messy or inconsistent.
Address som review concerns while I'm here, like rename the pseudo-rng
to 'dummy'.
# Submitted by: Arthur Mesh <arthurmesh@gmail.com> (the first item)
------------------------------------------------------------------------
r255319 | markm | 2013-09-06 18:51:52 +0100 (Fri, 06 Sep 2013) | 4 lines
Yarrow wants entropy estimations to be conservative; the usual idea
is that if you are certain you have N bits of entropy, you declare
N/2.
------------------------------------------------------------------------
r255075 | markm | 2013-08-30 18:47:53 +0100 (Fri, 30 Aug 2013) | 4 lines
Remove short-lived idea; thread to harvest (eg) RDRAND enropy into the
usual harvest queues. It was a nifty idea, but too heavyweight.
# Submitted by: Arthur Mesh <arthurmesh@gmail.com>
------------------------------------------------------------------------
r255071 | markm | 2013-08-30 12:42:57 +0100 (Fri, 30 Aug 2013) | 4 lines
Separate out the Software RNG entropy harvesting queue and thread
into its own files.
# Submitted by: Arthur Mesh <arthurmesh@gmail.com>
------------------------------------------------------------------------
r254934 | markm | 2013-08-26 20:07:03 +0100 (Mon, 26 Aug 2013) | 2 lines
Remove the short-lived namei experiment.
------------------------------------------------------------------------
r254928 | markm | 2013-08-26 19:35:21 +0100 (Mon, 26 Aug 2013) | 2 lines
Snapshot; Do some running repairs on entropy harvesting. More needs
to follow.
------------------------------------------------------------------------
r254927 | markm | 2013-08-26 19:29:51 +0100 (Mon, 26 Aug 2013) | 15 lines
Snapshot of current work;
1) Clean up namespace; only use "Yarrow" where it is Yarrow-specific
or close enough to the Yarrow algorithm. For the rest use a neutral
name.
2) Tidy up headers; put private stuff in private places. More could
be done here.
3) Streamline the hashing/encryption; no need for a 256-bit counter;
128 bits will last for long enough.
There are bits of debug code lying around; these will be removed
at a later stage.
------------------------------------------------------------------------
r254784 | markm | 2013-08-24 14:54:56 +0100 (Sat, 24 Aug 2013) | 39 lines
1) example (partially humorous random_adaptor, that I call "EXAMPLE")
* It's not meant to be used in a real system, it's there to show how
the basics of how to create interfaces for random_adaptors. Perhaps
it should belong in a manual page
2) Move probe.c's functionality in to random_adaptors.c
* rename random_ident_hardware() to random_adaptor_choose()
3) Introduce a new way to choose (or select) random_adaptors via tunable
"rngs_want" It's a list of comma separated names of adaptors, ordered
by preferences. I.e.:
rngs_want="yarrow,rdrand"
Such setting would cause yarrow to be preferred to rdrand. If neither of
them are available (or registered), then system will default to
something reasonable (currently yarrow). If yarrow is not present, then
we fall back to the adaptor that's first on the list of registered
adaptors.
4) Introduce a way where RNGs can play a role of entropy source. This is
mostly useful for HW rngs.
The way I envision this is that every HW RNG will use this
functionality by default. Functionality to disable this is also present.
I have an example of how to use this in random_adaptor_example.c (see
modload event, and init function)
5) fix kern.random.adaptors from
kern.random.adaptors: yarrowpanicblock
to
kern.random.adaptors: yarrow,panic,block
6) add kern.random.active_adaptor to indicate currently selected
adaptor:
root@freebsd04:~ # sysctl kern.random.active_adaptor
kern.random.active_adaptor: yarrow
# Submitted by: Arthur Mesh <arthurmesh@gmail.com>
Submitted by: Dag-Erling Smørgrav <des@FreeBSD.org>, Arthur Mesh <arthurmesh@gmail.com>
Reviewed by: des@FreeBSD.org
Approved by: re (delphij)
Approved by: secteam (des,delphij)
called. This probably should be fixed eventually, but for now it is
not needed to try to flush such vnodes from the buffer allocation
context.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (gjb)
really belong to it. Such vnodes, with the pointers to other vnodes
v_objects, are typically instantiated by the bypass filesystems.
Invalidating mappings of other vnode pages and the pages is wrong,
since reclamation of the upper vnode does not imply that lower vnode
is reclaimed too.
One of the consequences of the improper reclamation was destruction of
the wired mappings of the lower vnode pages, triggering miscellaneous
assertions in the VM system.
Reported by: John Marshall <john.marshall@riverwillow.com.au>
Tested by: John Marshall <john.marshall@riverwillow.com.au>, pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (gjb)
allocated, but the old table is kept around to handle the case of
threads still performing unlocked accesses to it.
Grow the table exponentially instead of increasing its size by
sizeof(long) * 8 chunks when overflowing. This mode significantly
reduces the total memory use for the processes consuming large numbers
of the file descriptors which open them one by one.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (marius)
mbufs, but return chain of free mbufs to a caller. Caller can either reuse
them or return to allocator in a batch manner.
- Implement sbdrop()/sbdrop_locked() as a wrapper around sbcut_internal().
- Expose sbcut_locked() for outside usage.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
Approved by: re (marius)
Add a SYSINIT that forces a reseed during proc0 setup, which happens
fairly late in the boot process.
Add a RANDOM_DEBUG option which enables some debugging printf()s.
Add a new RANDOM_ATTACH entropy source which harvests entropy from the
get_cyclecount() delta across each call to a device attach method.
This means we can't count on /var being present, so something will need to be done about harvesting /var/db/entropy/... .
Some policy now needs to be sorted out, and a pre-sync cache needs to be written, but apart from that we are now ready to go.
Over to review.
Looking pretty good; this mostly works now. New code includes:
* Read cached entropy at startup, both from files and from loader(8) preloaded entropy. Failures are soft, but announced. Untested.
* Use EVENTHANDLER to do above just before we go multiuser. Untested.
kmeminit() runs, so it contributes nothing to 'vm_kmem_size'; update a
comment to reflect that r254025 replaced the kmem submap with the kmem
arena.
Reviewed by: kib
Approved by: re (gjb)
Sponsored by: EMC / Isilon Storage Division
Contains:
* Refactor the hardware RNG CPU instruction sources to feed into
the software mixer. This is unfinished. The actual harvesting needs
to be sorted out. Modified by me (see below).
* Remove 'frac' parameter from random_harvest(). This was never
used and adds extra code for no good reason.
* Remove device write entropy harvesting. This provided a weak
attack vector, was not very good at bootstrapping the device. To
follow will be a replacement explicit reseed knob.
* Separate out all the RANDOM_PURE sources into separate harvest
entities. This adds some secuity in the case where more than one
is present.
* Review all the code and fix anything obviously messy or inconsistent.
Address som review concerns while I'm here, like rename the pseudo-rng
to 'dummy'.
Submitted by: Arthur Mesh <arthurmesh@gmail.com> (the first item)
not strlen as they are *not* strings.
Discovered by GSOC student, Mike Ma <mikemandarine@gmail.com> during his
fuse.glusterfs port to FreeBSD.
Final patch from mckusick@
Submitted by: mckusick@
Approved by: re (hrs)
MFC after: 2 weeks
is no sense to walk the whole dirty buffer queue. We are only
interested in, and can operate on, the buffers owned by the current
vnode [1]. Instead of calling generic queue flush routine, do
VOP_FSYNC() if possible.
Holding the dirty buffer queue lock in the bufdaemon, without dropping
it, can cause starvation of buffer writes from other threads. This is
esp. easy to reproduce on the big memory machines, where large files
are written, causing almost all dirty buffers accumulating in several
big files, which vnodes are locked by writers. Bufdaemon cannot flush
any buffer, but is iterating over the whole dirty queue
continuously. Since dirty queue mutex is not dropped, bufdone() in
g_up thread is starved, usually deadlocking the machine [2]. Mitigate
this by dropping the queue lock after the vnode is locked, allowing
other queue lock contenders to make a progress.
Discussed with: Jeff [1]
Reported by: pho [2]
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Approved by: re (hrs)
with the vnode shared-locked. If upgrade succeeded, the inactivation
can be done immediately, instead of being postponed.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (glebius)
The r255797 was:
Increase the chance of the buffer write from the bufdaemon helper
context to succeed. If the locked vnode which owns the buffer to be
written is shared locked, try the non-blocking upgrade of the lock to
exclusive.
PR: kern/178997
Reported and tested by: Klaus Weber <fbsd-bugs-2013-1@unix-admin.de>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (glebius)
atomically upgrade shared lock to exclusive. On failure, error is
returned and lock is not dropped in the process.
Tested by: pho (previous version)
No objections from: attilio
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (glebius)
negative timeout both before and after the conversion to sbintime_t.
For periodic kqueue timer, convert zero timeout into 1ms, to avoid
interrupt storm on fast event timers.
Reported and tested by: pho
Discussed with: mav
Reviewed by: davide
Sponsored by: The FreeBSD Foundation
Approved by: re (marius)
Otherwise, knote keeps a pointer to a vnode which could become invalid
any time.
Reported by: many
Tested by: Patrick Lamaiziere <patfbsd@davenulle.org>
Discussed with: jmg
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (marius)
Without these, if the timeout value passed is "large enough", the
value of the sum of it and other factors (e.g. current time as
returned by sbinuptime() or 'precision' argument) might result in a
negative number. This negative number is then passed to
eventtimers(4), which causes et_start() routine to load et_min_period
into eventtimer, making the CPU where the thread is stuck forever in
timer interrupt handler routine. This is now avoided rounding to
INT64_MAX the timeout period in case of overflow.
Reported by: kib, pho
Discussed with: kib, mav
Tested by: pho (stress2 suite, kevent7.sh scenario)
Approved by: re (kib)
seeing a stale fd_ofiles table once fd_nfiles is already updated,
resulting in OOB accesses.
Approved by: re (kib)
Sponsored by: EMC / Isilon storage division
Reported and tested by: pho
Reviewed by: benno
measurement of load caused by time-related events still using hardclock.
For example, without this change dummynet, scheduling events each hardclock
tick, was always miscounted as load of 1.
There is still aliasing with events delayed by the new precision mechanism,
but it probably can't be avoided without moving this sampling from using
callout to some lower-level code or handling it in some other special way.
Reviewed by: davide
Approved by: re (marius)
code could need to remove a kqueue from the filedesc list. Global
lock is already locked, which causes sleepable after non-sleepable
lock acquisition.
Reported and tested by: pho
Reviewed by: jmg
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Approved by: re (gjb)
context to succeed. If the locked vnode which owns the buffer to be
written is shared locked, try the non-blocking upgrade of the lock to
exclusive.
PR: kern/178997
Reported and tested by: Klaus Weber <fbsd-bugs-2013-1@unix-admin.de>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (marius)
shared-held locks for all the primitives in lc_lock/lc_unlock routines.
This fixes the problems introduced in r255747, which indeed introduced an
inversion in the logic.
Reported by: many
Tested by: bdrewery, pho, lme, Adam McDougall, O. Hartmann
Approved by: re (glebius)
there as "kern.ipc.sendfile.readahead".
- Push all nsfbuf related tunables into MD code. Don't move them
to new namespace in favor of POLA.
Reviewed by: scottl
Approved by: re (gjb)
revision 255744.
sys/kern/subr_smp.c:
IPI_SUSPEND is only available on amd64 and i386. Protect
new uses of this constant with #ifdefs to avoid impacting
other platforms.
Approved by: re (blanket Xen)
rm_priotracker' directly in the softclock thread. Now consumers can
pass CALLOUT_SHAREDLOCK flag to callout initialization routine safely.
The choice of the already existing flags instead of special casing
shared rmlocks is done to prevent consumer footshooting.
Suggested by: jhb
Reviewed by: jhb
Approved by: re (delphij)
current lock classes KPI it was really difficult because there was no
way to pass an rmtracker object to the lock/unlock routines. In order
to accomplish the task, modify the aforementioned functions so that
they can return (or pass as argument) an uinptr_t, which is in the rm
case used to hold a pointer to struct rm_priotracker for current
thread. As an added bonus, this fixes rm_sleep() in the rm shared
case, which right now can communicate priotracker structure between
lc_unlock()/lc_lock().
Suggested by: jhb
Reviewed by: jhb
Approved by: re (delphij)
amd64 and i386.
Submitted by: Roger Pau Monné
Sponsored by: Citrix Systems R&D
Reviewed by: gibbs
Approved by: re (blanket Xen)
MFC after: 2 weeks
sys/amd64/amd64/mp_machdep.c:
sys/amd64/include/cpu.h:
sys/i386/i386/mp_machdep.c:
sys/i386/include/cpu.h:
- Introduce two new CPU hooks for initialization and resume
purposes. This allows us to get rid of the XENHVM ifdefs in
mp_machdep, and also sets some hooks into common code that can be
used by other hypervisor implementations.
sys/amd64/conf/XENHVM:
sys/i386/conf/XENHVM:
- Remove these configs now that GENERIC has builtin support for Xen
HVM.
sys/kern/subr_smp.c:
- Make sure there are no pending IPIs when suspending a system.
sys/x86/xen/hvm.c:
- Add cpu init and resume vectors that are called from mp_machdep
using the new hooks.
- Only clear the vcpu_info mapping data on resume. It is already
clear for the BSP on a cold boot and is set correctly as APs
are started.
- Gate xen_hvm_init_cpu only to systems running under Xen.
sys/x86/xen/xen_intr.c:
- Gate the setup of event channels only to systems running under Xen.
Xen PVHVM guest.
Submitted by: Roger Pau Monné
Sponsored by: Citrix Systems R&D
Reviewed by: gibbs
Approved by: re (blanket Xen)
MFC after: 2 weeks
sys/amd64/amd64/mp_machdep.c:
sys/i386/i386/mp_machdep.c:
- Make sure that are no MMU related IPIs pending on migration.
- Reset pending IPI_BITMAP on resume.
- Init vcpu_info on resume.
sys/amd64/include/intr_machdep.h:
sys/i386/include/intr_machdep.h:
sys/x86/acpica/acpi_wakeup.c:
sys/x86/x86/intr_machdep.c:
sys/x86/isa/atpic.c:
sys/x86/x86/io_apic.c:
sys/x86/x86/local_apic.c:
- Add a "suspend_cancelled" parameter to pic_resume(). For the
Xen PIC, restoration of interrupt services differs between
the aborted suspend and normal resume cases, so we must provide
this information.
sys/dev/acpica/acpi_timer.c:
sys/dev/xen/timer/timer.c:
sys/timetc.h:
- Don't swap out "suspend safe" timers across a suspend/resume
cycle. This includes the Xen PV and ACPI timers.
sys/dev/xen/control/control.c:
- Perform proper suspend/resume process for PVHVM:
- Suspend all APs before going into suspension, this allows us
to reset the vcpu_info on resume for each AP.
- Reset shared info page and callback on resume.
sys/dev/xen/timer/timer.c:
- Implement suspend/resume support for the PV timer. Since FreeBSD
doesn't perform a per-cpu resume of the timer, we need to call
smp_rendezvous in order to correctly resume the timer on each CPU.
sys/dev/xen/xenpci/xenpci.c:
- Don't reset the PCI interrupt on each suspend/resume.
sys/kern/subr_smp.c:
- When suspending a PVHVM domain make sure there are no MMU IPIs
in-flight, or we will get a lockup on resume due to the fact that
pending event channels are not carried over on migration.
- Implement a generic version of restart_cpus that can be used by
suspended and stopped cpus.
sys/x86/xen/hvm.c:
- Implement resume support for the hypercall page and shared info.
- Clear vcpu_info so it can be reset by APs when resuming from
suspension.
sys/dev/xen/xenpci/xenpci.c:
sys/x86/xen/hvm.c:
sys/x86/xen/xen_intr.c:
- Support UP kernel configurations.
sys/x86/xen/xen_intr.c:
- Properly rebind per-cpus VIRQs and IPIs on resume.
exhausted.
- Add a new protect(1) command that can be used to set or revoke protection
from arbitrary processes. Similar to ktrace it can apply a change to all
existing descendants of a process as well as future descendants.
- Add a new procctl(2) system call that provides a generic interface for
control operations on processes (as opposed to the debugger-specific
operations provided by ptrace(2)). procctl(2) uses a combination of
idtype_t and an id to identify the set of processes on which to operate
similar to wait6().
- Add a PROC_SPROTECT control operation to manage the protection status
of a set of processes. MADV_PROTECT still works for backwards
compatability.
- Add a p_flag2 to struct proc (and a corresponding ki_flag2 to kinfo_proc)
the first bit of which is used to track if P_PROTECT should be inherited
by new child processes.
Reviewed by: kib, jilles (earlier version)
Approved by: re (delphij)
MFC after: 1 month
While here, correct all consumers to pass NULL instead of 0 as we pass
capability rights as pointers now, not uint64_t.
Reported by: Daniel Peyrolon
Tested by: Daniel Peyrolon
Approved by: re (marius)
to implement epoll subset of functionality. The kqueue user data are 32bit
on i386 which is not enough for epoll user data so this patch overrides
kqueue fileops to maintain enough space in struct file.
Initial patch developed by me in 2007 and then extended and finished
by Yuri Victorovich.
Approved by: re (delphij)
Sponsored by: Google Summer of Code
Submitted by: Yuri Victorovich <yuri at rawbw dot com>
Tested by: Yuri Victorovich <yuri at rawbw dot com>
and the equivalent functionality is now provided by sendfile(2) over
posix shared memory filedescriptor.
Remove the cow member of struct vm_page, and rearrange the remaining
members. While there, make hold_count unsigned.
Requested and reviewed by: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
Approved by: re (delphij)
time removal on kqueue close.
Reported and tested by: pho
Reviewed by: jmg
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (delphij)
exclusively. Filesystems are assumed to disable shared locking for
the fifo vnode locks, but some do not.
Reported and tested by: olgeni
Discussed with: avg
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (glebius)
continuous calls to the uprintf(9), the proctree_lock could be
shared-locked for indefinite amount of time, starving exclusive
requests. Since proctree_lock is needed for fork() and exit(), this
effectively stops the machine.
While there, do the similar reduction for tprintf(9).
Reported and tested by: pho
Reviewed by: ed
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (glebius)
in addition to the regular files.
Requested by: alc
Discussed with: emaste
Tested by: pho (previous version)
Sponsored by: The FreeBSD Foundation
Approved by: re (hrs)
transmission which could be tricked into rounding up to the nearest
page size, leaking up to a page of kernel memory. [13:11]
In IPv6 and NetATM, stop SIOCSIFADDR, SIOCSIFBRDADDR, SIOCSIFDSTADDR
and SIOCSIFNETMASK at the socket layer rather than pass them on to the
link layer without validation or credential checks. [SA-13:12]
Prevent cross-mount hardlinks between different nullfs mounts of the
same underlying filesystem. [SA-13:13]
Security: CVE-2013-5666
Security: FreeBSD-SA-13:11.sendfile
Security: CVE-2013-5691
Security: FreeBSD-SA-13:12.ifioctl
Security: CVE-2013-5710
Security: FreeBSD-SA-13:13.nullfs
Approved by: re
an address in the first 2GB of the process's address space. This flag should
have the same semantics as the same flag on Linux.
To facilitate this, add a new parameter to vm_map_find() that specifies an
optional maximum virtual address. While here, fix several callers of
vm_map_find() to use a VMFS_* constant for the findspace argument instead of
TRUE and FALSE.
Reviewed by: alc
Approved by: re (kib)
an on-stack array to a pointer and therefore sizeof(errmsg) would
become 4 or 8 bytes depending on the architecture.
Fix this by using ERRMSGL in place of sizeof().
Submitted by: J David <j.david.lists@gmail.com>
MFC after: 3 days
Approved by: re (kib)
pmap_remove_all(). Not doing the drain allows the pmap_enter() to
proceed in parallel, making the pmap_remove_all() effects void.
The race results in an invalidated page mapped wired by usermode.
Reported and tested by: pho
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
Approved by: re (glebius)
ffsl() implementation, when it is available, instead of homegrown iteration.
On dual-E5645 amd64 system (2x6x2 cores) under heavy I/O load that reduces
time spent inside cpu_search() from 19% to 13%, while IOPS increased by 5%.
run. After that, the pager put method is called, usually translated
to VOP_WRITE(). For the filesystems which use buffer cache,
bufwrite() sbusies the buffer pages again, waiting for the xbusy state
to drain. The later is done in vfs_drain_busy_pages(), which is
called with the buffer pages already sbusied (by vm_pageout_flush()).
Since vfs_drain_busy_pages() can only wait for one page at the time,
and during the wait, the object lock is dropped, previous pages in the
buffer must be protected from other threads busying them. Up to the
moment, it was done by xbusying the pages, that is incompatible with
the sbusy state in the new implementation of busy. Switch to sbusy.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
in the future in a backward compatible (API and ABI) way.
The cap_rights_t represents capability rights. We used to use one bit to
represent one right, but we are running out of spare bits. Currently the new
structure provides place for 114 rights (so 50 more than the previous
cap_rights_t), but it is possible to grow the structure to hold at least 285
rights, although we can make it even larger if 285 rights won't be enough.
The structure definition looks like this:
struct cap_rights {
uint64_t cr_rights[CAP_RIGHTS_VERSION + 2];
};
The initial CAP_RIGHTS_VERSION is 0.
The top two bits in the first element of the cr_rights[] array contain total
number of elements in the array - 2. This means if those two bits are equal to
0, we have 2 array elements.
The top two bits in all remaining array elements should be 0.
The next five bits in all array elements contain array index. Only one bit is
used and bit position in this five-bits range defines array index. This means
there can be at most five array elements in the future.
To define new right the CAPRIGHT() macro must be used. The macro takes two
arguments - an array index and a bit to set, eg.
#define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL)
We still support aliases that combine few rights, but the rights have to belong
to the same array element, eg:
#define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL)
#define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL)
#define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP)
There is new API to manage the new cap_rights_t structure:
cap_rights_t *cap_rights_init(cap_rights_t *rights, ...);
void cap_rights_set(cap_rights_t *rights, ...);
void cap_rights_clear(cap_rights_t *rights, ...);
bool cap_rights_is_set(const cap_rights_t *rights, ...);
bool cap_rights_is_valid(const cap_rights_t *rights);
void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);
Capability rights to the cap_rights_init(), cap_rights_set(),
cap_rights_clear() and cap_rights_is_set() functions are provided by
separating them with commas, eg:
cap_rights_t rights;
cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT);
There is no need to terminate the list of rights, as those functions are
actually macros that take care of the termination, eg:
#define cap_rights_set(rights, ...) \
__cap_rights_set((rights), __VA_ARGS__, 0ULL)
void __cap_rights_set(cap_rights_t *rights, ...);
Thanks to using one bit as an array index we can assert in those functions that
there are no two rights belonging to different array elements provided
together. For example this is illegal and will be detected, because CAP_LOOKUP
belongs to element 0 and CAP_PDKILL to element 1:
cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL);
Providing several rights that belongs to the same array's element this way is
correct, but is not advised. It should only be used for aliases definition.
This commit also breaks compatibility with some existing Capsicum system calls,
but I see no other way to do that. This should be fine as Capsicum is still
experimental and this change is not going to 9.x.
Sponsored by: The FreeBSD Foundation
of relying on the tvtohz() workaround. The latter has been introduced
lately by jhb@ (r254699) in order to have a fix that can be backported
to STABLE.
Reported by: Vitja Makarov <vitja.makarov at gmail dot com>
Reviewed by: jhb (earlier version)
waiting for an RPC reply from the server while holding the mount
point busy (mnt_lockref incremented). This happens because dounmount()
msleep()s waiting for mnt_lockref to become 0, before calling
VFS_UNMOUNT(). This patch adds a new VFS operation called VFS_PURGE(),
which the NFS client implements as purging RPCs in progress. Making
this call before checking mnt_lockref fixes the problem, by ensuring
that the VOP_xxx() calls will fail and unbusy the mount point.
Reported by: sbruno
Reviewed by: kib
MFC after: 2 weeks
- Remove excessive parenthesis
- Use KNF continuation indentation
- Cut down on excessive continuation lines
- More consistent style in messages
- Use uprintf() instead of printf()
Submitted by: bde
problems with the way MLEN, MHLEN, and struct mbuf are set up.
CTASSERT's are provided to detect such issues at compile time in the
future.
The #define MLEN and MHLEN calculation do not take actual compiler-
induced alignment and padding inside the complete struct mbuf into
account. Accordingly appropriate attention is required when changing
members of struct mbuf.
Ideally one would calculate MLEN as (MSIZE - sizeof(((struct mbuf *)0)->m_hdr)
but that doesn't work as the compiler refuses to operate on an as of
yet incomplete structure.
In particular ARM 32bit has more strict alignment requirements which
caused 4 bytes of padding between m_hdr and pkthdr in struct mbuf
because of the 64bit members in pkthdr. This wasn't picked up by MLEN
and MHLEN causing an overflow of the mbuf provided data storage by
overestimating its size.
I386 didn't show this problem because it handles unaligned access just
fine, albeit at a small performance penalty.
On 64bit architectures the struct mbuf layout is 64bit aligned in all
places.
Reported by: Thomas Skibo <ThomasSkibo-at-sbcglobal-dot-net>
Tested by: tuexen, ian, Thomas Skibo (extended patch)
Sponsored by: The FreeBSD Foundation
for the available pbuf when passed vnode is backing md(4). Other i/o
directed to the same md device might already hold pbufs, and then we
could deadlock since only our progress can free a pbuf needed for
wakeup.
Obtained from: projects/vm6
Reminded and tested by: pho
MFC after: 1 week
ps(1) utility, e.g. "ps -O fib".
bin/ps/keyword.c:
Add the "fib" keyword and default its column name to "FIB".
bin/ps/ps.1:
Add "fib" as a supported keyword.
sys/compat/freebsd32/freebsd32.h:
sys/kern/kern_proc.c:
sys/sys/user.h:
Add the default fib number for a process (p->p_fibnum)
to the user land accessible process data of struct kinfo_proc.
Submitted by: Oliver Fromme <olli@fromme.com>, gibbs
external mbuf buffer management capabilities in the future.
For now only EXT_FREE_OK is defined with current legacy behavior.
Sponsored by: The FreeBSD Foundation
kld_unload event handler which gets invoked after a linker file has been
successfully unloaded. The kld_unload and kld_load event handlers are now
invoked with the shared linker lock held, while kld_unload_try is invoked
with the lock exclusively held.
Convert hwpmc(4) to use these event handlers instead of having
kern_kldload() and kern_kldunload() invoke hwpmc(4) hooks whenever files are
loaded or unloaded. This has no functional effect, but simplifes the linker
code somewhat.
Reviewed by: jhb
2 predictable branches nowadays. However as a pre-condition the
caller had to ensure that the mbuf pkthdr did not have any mtags
attached to it, costing some potential branches again.
Sponsored by: The FreeBSD Foundation
linker_init_kernel_modules() and linker_preload() in order to remove most
of the checks for !cold before asserting that the kld lock is held. These
routines are invoked by SYSINIT(9), so there's no harm in them taking the
kld lock.
features. The changes in particular are:
o Remove rarely used "header" pointer and replace it with a 64bit protocol/
layer specific union PH_loc for local use. Protocols can flexibly overlay
their own 8 to 64 bit fields to store information while the packet is
worked on.
o Mechanically convert IP reassembly, IGMP/MLD and ATM to use pkthdr.PH_loc
instead of pkthdr.header.
o Extend csum_flags to 64bits to allow for additional future offload
information to be carried (e.g. iSCSI, IPsec offload, and others).
o Move the RSS hash type enumerator from abusing m_flags to its own 8bit
rsstype field. Adjust accessor macros.
o Add cosqos field to store Class of Service / Quality of Service information
with the packet. It is not yet supported in any drivers but allows us to
get on par with Cisco/Juniper in routing applications (plus MPLS QoS) with
a modernized ALTQ.
o Add four 8 bit fields l[2-5]hlen to store the relative header offsets
from the start of the packet. This is important for various offload
capabilities and to relieve the drivers from having to parse the packet
and protocol headers to find out location of checksums and other
information. Header parsing in drivers is a lot of copy-paste and
unhandled corner cases which we want to avoid.
o Add another flexible 64bit union to map various additional persistent
packet information, like ether_vtag, tso_segsz and csum fields.
Depending on the csum_flags settings some fields may have different usage
making it very flexible and adaptable to future capabilities.
o Restructure the CSUM flags to better signify their outbound (down the
stack) and inbound (up the stack) use. The CSUM flags used to be a bit
chaotic and rather poorly documented leading to incorrect use in many
places. Bring clarity into their use through better naming.
Compatibility mappings are provided to preserve the API. The drivers
can be corrected one by one and MFC'd without issue.
o The size of pkthdr stays the same at 48/56bytes (32/64bit architectures).
Sponsored by: The FreeBSD Foundation
free function access to the mbuf the external memory was attached
to.
Mechanically adjust all users to include the mbuf parameter.
This fixes a long standing annoyance for external free functions.
Before one had to sacrifice one of the argument pointers for this.
Sponsored by: The FreeBSD Foundation
Remove locking from taskqueue_member(). The list of threads is static
during the taskqueue life cycle, so there is no need to protect it,
taking quite congested lock several more times for each ZFS I/O.
to 8 bits. ext_type is an enumerator and the number of types we
have is a mere dozen.
A couple of ext_types are renumbered to fit within 8 bits.
EXT_VENDOR[1-4] and EXT_EXP[1-4] types for vendor-internal and
experimental local mapping.
The ext_flags field is currently unused but has a couple of flags
already defined for future use. Again vendor and experimental
flags are provided for local mapping.
EXT_FLAG_BITS is provided for the printf(9) %b identifier.
Initialize and copy ext_flags in the relevant mbuf functions.
Improve alignment and packing of struct m_ext on 32 and 64 archs
by carefully sorting the fields.
configure sa(4) to request no I/O splitting by default.
For tape devices, the user needs to be able to clearly understand
what blocksize is actually being used when writing to a tape
device. The previous behavior of physio(9) was that it would split
up any I/O that was too large for the device, or too large to fit
into MAXPHYS. This means that if, for instance, the user wrote a
1MB block to a tape device, and MAXPHYS was 128KB, the 1MB write
would be split into 8 128K chunks. This would be done without
informing the user.
This has suboptimal effects, especially when trying to communicate
status to the user. In the event of an error writing to a tape
(e.g. physical end of tape) in the middle of a 1MB block that has
been split into 8 pieces, the user could have the first two 128K
pieces written successfully, the third returned with an error, and
the last 5 returned with 0 bytes written. If the user is using
a standard write(2) system call, all he will see is the ENOSPC
error. He won't have a clue how much actually got written. (With
a writev(2) system call, he should be able to determine how much
got written in addition to the error.)
The solution is to prevent physio(9) from splitting the I/O. The
new cdev flag, SI_NOSPLIT, tells physio that the driver does not
want I/O to be split beforehand.
Although the sa(4) driver now enables SI_NOSPLIT by default,
that can be disabled by two loader tunables for now. It will not
be configurable starting in FreeBSD 11.0. kern.cam.sa.allow_io_split
allows the user to configure I/O splitting for all sa(4) driver
instances. kern.cam.sa.%d.allow_io_split allows the user to
configure I/O splitting for a specific sa(4) instance.
There are also now three sa(4) driver sysctl variables that let the
users see some sa(4) driver values. kern.cam.sa.%d.allow_io_split
shows whether I/O splitting is turned on. kern.cam.sa.%d.maxio shows
the maximum I/O size allowed by kernel configuration parameters
(e.g. MAXPHYS, DFLTPHYS) and the capabilities of the controller.
kern.cam.sa.%d.cpi_maxio shows the maximum I/O size supported by
the controller.
Note that a better long term solution would be to implement support
for chaining buffers, so that that MAXPHYS is no longer a limiting
factor for I/O size to tape and disk devices. At that point, the
controller and the tape drive would become the limiting factors.
sys/conf.h: Add a new cdev flag, SI_NOSPLIT, that allows a
driver to tell physio not to split up I/O.
sys/param.h: Bump __FreeBSD_version to 1000049 for the addition
of the SI_NOSPLIT cdev flag.
kern_physio.c: If the SI_NOSPLIT flag is set on the cdev, return
any I/O that is larger than si_iosize_max or
MAXPHYS, has more than one segment, or would have
to be split because of misalignment with EFBIG.
(File too large).
In the event of an error, print a console message to
give the user a clue about what happened.
scsi_sa.c: Set the SI_NOSPLIT cdev flag on the devices created
for the sa(4) driver by default.
Add tunables to control whether we allow I/O splitting
in physio(9).
Explain in the comments that allowing I/O splitting
will be deprecated for the sa(4) driver in FreeBSD
11.0.
Add sysctl variables to display the maximum I/O
size we can do (which could be further limited by
read block limits) and the maximum I/O size that
the controller can do.
Limit our maximum I/O size (recorded in the cdev's
si_iosize_max) by MAXPHYS. This isn't strictly
necessary, because physio(9) will limit it to
MAXPHYS, but it will provide some clarity for the
application.
Record the controller's maximum I/O size reported
in the Path Inquiry CCB.
sa.4: Document the block size behavior, and explain that
the option of allowing physio(9) to split the I/O
will disappear in FreeBSD 11.0.
Sponsored by: Spectra Logic
does not make sense to wait for the soft busy state of the page to
drain. The vm object lock is dropped immediately after, so the result
of the wait is invalidated.
It might make sense to not wait for the hard busy state as well,
esp. for the fully valid page, but this is postponed for now.
Reviewed by: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
than using a home-rolled version. The home-rolled version could result
in shorter-than-requested sleeps.
Reported by: Vitja Makarov <vitja.makarov@gmail.com>
MFC after: 2 weeks
shared busy without first draining the hard busy state. Previously it
went unnoticed since VPO_BUSY and m->busy fields were distinct, and
vm_page_io_start() did not verified that the passed page has VPO_BUSY
flag cleared, but such page state is wrong. New implementation is
more strict and catched this case.
Drain the busy state as needed, before calling vm_page_sbusy().
Tested by: pho, jkim
Sponsored by: The FreeBSD Foundation
The flag was mandatory since r209792, where vm_page_grab(9) was
changed to only support the alloc retry semantic.
Suggested and reviewed by: alc
Sponsored by: The FreeBSD Foundation
Add MAC framework entries for posix shm read and write.
Do not allow implicit extension of the underlying memory segment past
the limit set by ftruncate(2) by either of the syscalls. Read and
write returns short i/o, lseek(2) fails with EINVAL when resulting
offset does not fit into the limit.
Discussed with: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
that don't support superpages. This keeps the number of spans and internal
fragmentation lower.
- When the user asks for alignment from vmem_xalloc adjust the imported size
by 2*align to be certain we can satisfy the allocation. This comes at
the expense of potential failures when the backend can't supply enough
memory but could supply the requested size and alignment.
Sponsored by: EMC / Isilon Storage Division
for a very long time, if ever.
Should such a functionality ever be needed again the appropriate and
much better way to do it is through a custom EXT_SOMETHING external mbuf
type together with a dedicated *ext_free function.
Discussed with: trociny, glebius
