implementation is by no means perfect as far as some of the algorithms
that it uses and the fact that it is missing some functionality (try
locks and upgrades/downgrades are not there yet), however it does seem
to work in my local testing. There is more detail in the comments in the
code, but the short version follows.
A reader/writer lock is very much like a regular mutex: it cannot be held
across a voluntary sleep; it can be acquired in an interrupt thread; if
the lock is held by a writer then the priority of any threads that block
on the lock will be lent to the owner; the simple case lock operations all
are done in a single atomic op. It also shares some similiarities
with sx locks: it supports reader/writer semantics (multiple readers,
but single writers); readers are allowed to recurse, but writers are not.
We can extend this implementation further by either improving algorithms
or adding new functionality, but this should at least give us a base to
work with now.
Reviewed by: arch (in theory)
Tested on: i386 (4 cpu box with a kernel module that used 4 threads
that randomly chose between read locks and write locks
that ran w/o panicing for over a day solid. It usually
panic'd within a few seconds when there were bugs during
testing. :) The kernel module source is available on
request.)
to COMPAT_43TTY.
Add COMPAT_43TTY to NOTES and */conf/GENERIC
Compile tty_compat.c only under the new option.
Spit out
#warning "Old BSD tty API used, please upgrade."
if ioctl_compat.h gets #included from userland.
that NetBSD implemented it independently of them (don't know which one
was actually first). This saves about 24k for those times you don't
need snapshot support (like when running off a ram disk, or in an
embedded environment where size matters).
- provide an interface (macros) to the page coloring part of the VM system,
this allows to try different coloring algorithms without the need to
touch every file [1]
- make the page queue tuning values readable: sysctl vm.stats.pagequeue
- autotuning of the page coloring values based upon the cache size instead
of options in the kernel config (disabling of the page coloring as a
kernel option is still possible)
MD changes:
- detection of the cache size: only IA32 and AMD64 (untested) contains
cache size detection code, every other arch just comes with a dummy
function (this results in the use of default values like it was the
case without the autotuning of the page coloring)
- print some more info on Intel CPU's (like we do on AMD and Transmeta
CPU's)
Note to AMD owners (IA32 and AMD64): please run "sysctl vm.stats.pagequeue"
and report if the cache* values are zero (= bug in the cache detection code)
or not.
Based upon work by: Chad David <davidc@acns.ab.ca> [1]
Reviewed by: alc, arch (in 2004)
Discussed with: alc, Chad David, arch (in 2004)
originally wrote it for 4.x and hasn't really had the time to fully update
it to 5.x and later. Also, the author doesn't use the hardware anymore as
well. If someone does need this driver they can always resurrect it from
the Attic.
Requested by: Frank Mayhar frank at exit dot com
opt_device_polling.h
- Include opt_device_polling.h into appropriate files.
- Embrace with HAVE_KERNEL_OPTION_HEADERS the include in the files that
can be compiled as loadable modules.
Reviewed by: bde
replacement and has additional features which make it superior.
Discussed on: -arch
Reviewed by: thompsa
X-MFC-after: never (RELENG_6 as transition period)
a problem with one particular switch module. Create a kernel option
BGE_FAKE_AUTONEG that restores the 5.4 behavior, which should make the DNLK
switch module work. IBM/Intel blades with Intel or AD switch modules should
work without patching or kernel options with this commit.
Hardware for testing provided by several folks, including
Danny Braniss <danny@cs.huji.ac.il>, Achim Patzner <ap@bnc.net>,
and OffMyServer.
Approved by: re
o ATA is now fully newbus'd and split into modules.
This means that on a modern system you just load "atapci and ata"
to get the base support, and then one or more of the device
subdrivers "atadisk atapicd atapifd atapist ataraid".
All can be loaded/unloaded anytime, but for obvious reasons you
dont want to unload atadisk when you have mounted filesystems.
o The device identify part of the probe has been rewritten to fix
the problems with odd devices the old had, and to try to remove
so of the long delays some HW could provoke. Also probing is done
without the need for interrupts, making earlier probing possible.
o SATA devices can be hot inserted/removed and devices will be created/
removed in /dev accordingly.
NOTE: only supported on controllers that has this feature:
Promise and Silicon Image for now.
On other controllers the usual atacontrol detach/attach dance is
still needed.
o Support for "atomic" composite ATA requests used for RAID.
o ATA RAID support has been rewritten and and now supports these
metadata formats:
"Adaptec HostRAID"
"Highpoint V2 RocketRAID"
"Highpoint V3 RocketRAID"
"Intel MatrixRAID"
"Integrated Technology Express"
"LSILogic V2 MegaRAID"
"LSILogic V3 MegaRAID"
"Promise FastTrak"
"Silicon Image Medley"
"FreeBSD PseudoRAID"
o Update the ioctl API to match new RAID levels etc.
o Update atacontrol to know about the new RAID levels etc
NOTE: you need to recompile atacontrol with the new sys/ata.h,
make world will take care of that.
NOTE2: that rebuild is done differently from the old system as
the rebuild is now done piggybacked on read requests to the
array, so atacontrol simply starts a background "dd" to rebuild
the array.
o The reinit code has been worked over to be much more robust.
o The timeout code has been overhauled for races.
o Support of new chipsets.
o Lots of fixes for bugs found while doing the modulerization and
reviewing the old code.
Missing or changed features from current ATA:
o atapi-cd no longer has support for ATAPI changers. Todays its
much cheaper and alot faster to copy those CD images to disk
and serve them from there. Besides they dont seem to be made
anymore, maybe for that exact reason.
o ATA RAID can only read metadata from all the above metadata formats,
not write all of them (Promise and Highpoint V2 so far). This means
that arrays can be picked up from the BIOS, but they cannot be
created from FreeBSD. There is more to it than just the missing
write metadata support, those formats are not unique to a given
controller like Promise and Highpoint formats, instead they exist
for several types, and even worse, some controllers can have
different formats and its impossible to tell which one.
The outcome is that we cannot reliably create the metadata of those
formats and be sure the controller BIOS will understand it.
However write support is needed to update/fail/rebuild the arrays
properly so it sits fairly high on the TODO list.
o So far atapicam is not supported with these changes. When/if this
will change is up to the maintainer of atapi-cam so go there for
questions.
HW donated by: Webveveriet AS
HW donated by: Frode Nordahl
HW donated by: Yahoo!
HW donated by: Sentex
Patience by: Vife and my boys (and even the cats)
with the kernel compile time option:
options IPFIREWALL_FORWARD_EXTENDED
This option has to be specified in addition to IPFIRWALL_FORWARD.
With this option even packets targeted for an IP address local
to the host can be redirected. All restrictions to ensure proper
behaviour for locally generated packets are turned off. Firewall
rules have to be carefully crafted to make sure that things like
PMTU discovery do not break.
Document the two kernel options.
PR: kern/71910
PR: kern/73129
MFC after: 1 week
hosts to share an IP address, providing high availability and load
balancing.
Original work on CARP done by Michael Shalayeff, with many
additions by Marco Pfatschbacher and Ryan McBride.
FreeBSD port done solely by Max Laier.
Patch by: mlaier
Obtained from: OpenBSD (mickey, mcbride)
and wd80x3 support. Make the obscure ISA cards optional, and add
those options to NOTES on i386 (note: the ifdef around the whole code
is for module building). Tweak pc98 ed support to include wd80x3 too.
Add goo for alpha too.
The affected cards are the 3Com 3C503, HP LAN+ and SIC (whatever that
is). I couldn't find any of these for sale on ebay, so they are
untested. If you have one of these cards, and send it to me, I'll
ensure that you have no future problems with it...
Minor cleanups as well by using functions rather than cut and paste
code for some probing operations (where the function call overhead is
lost in the noise).
Remove use of kvtop, since they aren't required anymore. This driver
needs to get its memory mapped act together, however, and use bus
space. It doesn't right now.
This reduces the size of if_ed.ko from about 51k to 33k on my laptop.
designed to help detect tamper-after-free scenarios, a problem more
and more common and likely with multithreaded kernels where race
conditions are more prevalent.
Currently MemGuard can only take over malloc()/realloc()/free() for
particular (a) malloc type(s) and the code brought in with this
change manually instruments it to take over M_SUBPROC allocations
as an example. If you are planning to use it, for now you must:
1) Put "options DEBUG_MEMGUARD" in your kernel config.
2) Edit src/sys/kern/kern_malloc.c manually, look for
"XXX CHANGEME" and replace the M_SUBPROC comparison with
the appropriate malloc type (this might require additional
but small/simple code modification if, say, the malloc type
is declared out of scope).
3) Build and install your kernel. Tune vm.memguard_divisor
boot-time tunable which is used to scale how much of kmem_map
you want to allott for MemGuard's use. The default is 10,
so kmem_size/10.
ToDo:
1) Bring in a memguard(9) man page.
2) Better instrumentation (e.g., boot-time) of MemGuard taking
over malloc types.
3) Teach UMA about MemGuard to allow MemGuard to override zone
allocations too.
4) Improve MemGuard if necessary.
This work is partly based on some old patches from Ian Dowse.
an inordinate amount of synchronous console output that is fairly
undesirable on slower serial console. It's easily hit by accident
when frobbing other sysctls late at night.
Users should move to the new geom_vinum implementation instead.
The refcount logic which is being added to devices to enable safe module
unloading and the buf/vm work also in progress would require a major rework
of the (old)-vinum code to comply with the new semantics.
The actual source files will not be removed until I have coordinated with
the geomvinum people if they need any bits repo-copied etc.
FULL_PREEMPTION is defined. Add a runtime warning to ULE if PREEMPTION is
enabled (code inspired by the PREEMPTION warning in kern_switch.c). This
is a possible MT5 candidate.
remaining consumers to have the count passed as an option. This is
i4b, pc98/wdc, and coda.
Bump configvers.h from 500013 to 600000.
Remove heuristics that tried to parse "device ed5" as 5 units of the ed
device. This broke things like the snd_emu10k1 device, which required
quotes to make it parse right. The no-longer-needed quotes have been
removed from NOTES, GENERIC etc. eg, I've removed the quotes from:
device snd_maestro
device "snd_maestro3"
device snd_mss
I believe everything will still compile and work after this.
will cause the network stack to operate without the Giant lock by
default. This change has the potential to improve performance by
increasing parallelism and decreasing latency in network processing.
Due to the potential exposure of existing or new bugs, the following
compatibility functionality is maintained:
- It is still possible to disable Giant-free operation by setting
debug.mpsafenet to 0 in loader.conf.
- Add "options NET_WITH_GIANT", which will restore the default value of
debug.mpsafenet to 0, and is intended for use on systems compiled with
known unsafe components, or where a more conservative configuration is
desired.
- Add a new declaration, NET_NEEDS_GIANT("componentname"), which permits
kernel components to declare dependence on Giant over the network
stack. If the declaration is made by a preloaded module or a compiled
in component, the disposition of debug.mpsafenet will be set to 0 and
a warning concerning performance degraded operation printed to the
console. If it is declared by a loadable kernel module after boot, a
warning is displayed but the disposition cannot be changed. This is
implemented by defining a new SYSINIT() value, SI_SUB_SETTINGS, which
is intended for the processing of configuration choices after tunables
are read in and the console is available to generate errors, but
before much else gets going.
This compatibility behavior will go away when we've finished the last
of the locking work and are confident that operation is correct.
compile option. All FreeBSD packet filters now use the PFIL_HOOKS API and
thus it becomes a standard part of the network stack.
If no hooks are connected the entire packet filter hooks section and related
activities are jumped over. This removes any performance impact if no hooks
are active.
Both OpenBSD and DragonFlyBSD have integrated PFIL_HOOKS permanently as well.
