While the KSE project was quite successful in bringing threading to
FreeBSD, the M:N approach taken by the kse library was never developed
to its full potential. Backwards compatibility will be provided via
libmap.conf for dynamically linked binaries and static binaries will
be broken.
not have VTOC information about the partitions, it will be created.
This is because the VTOC information is used for the partition type
and FreeBSD's sunlabel(8) does not create nor use VTOC information.
For this purpose, new tags have been added to support FreeBSD's
partition types.
overridden at compile-time using kernel options of the same names.
Rather than doing a compile-time CTASSERT of buffer sizes being
even multiples of block sizes, just adjust them at boottime, as
the failure mode is more user-friendly.
MFC after: 2 months
PR: 119993
Suggested by: Scot Hetzel <swhetzel at gmail dot com>
the ABI when enabled. There is no longer an embedded lock_profile_object
in each lock. Instead a list of lock_profile_objects is kept per-thread
for each lock it may own. The cnt_hold statistic is now always 0 to
facilitate this.
- Support shared locking by tracking individual lock instances and
statistics in the per-thread per-instance lock_profile_object.
- Make the lock profiling hash table a per-cpu singly linked list with a
per-cpu static lock_prof allocator. This removes the need for an array
of spinlocks and reduces cache contention between cores.
- Use a seperate hash for spinlocks and other locks so that only a
critical_enter() is required and not a spinlock_enter() to modify the
per-cpu tables.
- Count time spent spinning in the lock statistics.
- Remove the LOCK_PROFILE_SHARED option as it is always supported now.
- Specifically drop and release the scheduler locks in both schedulers
since we track owners now.
In collaboration with: Kip Macy
Sponsored by: Nokia
o Disklabels can have between 8 and 20 partitions (inclusive).
o No device special file is created for the raw partition.
o Switch ia64 to use this backend.
o No support for boot code yet.
- Introduce per-architecture stack_machdep.c to hold stack_save(9).
- Introduce per-architecture machine/stack.h to capture any common
definitions required between db_trace.c and stack_machdep.c.
- Add new kernel option "options STACK"; we will build in stack(9) if it is
defined, or also if "options DDB" is defined to provide compatibility
with existing users of stack(9).
Add new stack_save_td(9) function, which allows the capture of a stacktrace
of another thread rather than the current thread, which the existing
stack_save(9) was limited to. It requires that the thread be neither
swapped out nor running, which is the responsibility of the consumer to
enforce.
Update stack(9) man page.
Build tested: amd64, arm, i386, ia64, powerpc, sparc64, sun4v
Runtime tested: amd64 (rwatson), arm (cognet), i386 (rwatson)
Currently, Giant is not too much contented so that it is ok to treact it
like any other mutexes.
Please don't forget to update your own custom config kernel files.
Approved by: cognet, marcel (maintainers of arches where option is
not enabled at the moment)
providers with limited physical storage and add physical storage as
needed.
Submitted by: Ivan Voras
Sponsored by: Google Summer of Code 2006
Approved by: re (kensmith)
other changes too).
(without any real order)
1. Use device_get_nameunit for mutex naming
2. Add timer for low-latency playback
3. Move most mixer controls from sysctls to mixer(8) controls.
This is a largest part of this patch.
4. Add analog/digital switch (as a temporary sysctl)
5. Get back support for low-bitrate playback (with help of (2))
6. Change locking for exclusive I/O. Writing to non-PTR register
is almost safe and does not need to be ordered with PTR operations.
7. Disable MIDI until we get it to detach properly and fix memory
managment problems.
8. Enable multichannel playback by default. It is as stable as
single-channel mode. Multichannel recording is still an
experimental feature.
9. Multichannel options can be changed by loader tunables.
10. Add a way to disable card from a loader tunable.
11. Add new PCI IDs.
12. Debugger settings are loader tunables now.
14. Remove some unused variables.
15. Mark pcm sub-devices MPSAFE.
16. Partially revert (bus_setup_intr -> snd_setup_intr) since it need
to be done independently
Submitted by: Yuriy Tsibizov (driver maintainer)
Approved by: re (bmah)
previously conditionally acquired Giant based on debug.mpsafenet. As that
has now been removed, they are no longer required. Removing them
significantly simplifies error-handling in the socket layer, eliminated
quite a bit of unwinding of locking in error cases.
While here clean up the now unneeded opt_net.h, which previously was used
for the NET_WITH_GIANT kernel option. Clean up some related gotos for
consistency.
Reviewed by: bz, csjp
Tested by: kris
Approved by: re (kensmith)
Also rename the related functions in a similar way.
There are no functional changes.
For a packet coming in with IPsec tunnel mode, the default is
to only call into the firewall with the "outer" IP header and
payload.
With this option turned on, in addition to the "outer" parts,
the "inner" IP header and payload are passed to the
firewall too when going through ip_input() the second time.
The option was never only related to a gif(4) tunnel within
an IPsec tunnel and thus the name was very misleading.
Discussed at: BSDCan 2007
Best new name suggested by: rwatson
Reviewed by: rwatson
Approved by: re (bmah)
included man pages on how to use it. This code is still somewhat experimental
but has been successfully tested on a number of targets. Many thanks to
Danny for contributing this.
Approved by: re
NET_NEEDS_GIANT, which will shortly be removed. This is done in a
away that it may be easily reattached to the build before 7.1 if
appropriate locking is added. Specifics:
- Don't install netatm include files
- Disconnect netatm command line management tools
- Don't build libatm
- Don't include ATM parts in rescue or sysinstall
- Don't install sample configuration files and documents
- Don't build kernel support as a module or in NOTES
- Don't build netgraph wrapper nodes for netatm
This removes the last remaining consumer of NET_NEEDS_GIANT.
Reviewed by: harti
Discussed with: bz, bms
Approved by: re (kensmith)
- CMT_PF states added (w/sysctl to turn the PF version on)
- sctp_input.c had a missing incr of cookie case when the
auth was bad. This meant a free was called without an
increment to refcnt, added increment like rest of code.
- There was a case, unlikely, when the scope of the destination
changed (this is a TSNH case). In that case, it would not free
the alloc'ed asoc (in sctp_input.c).
- When listed addresses found a colliding cookie/Init, then
the collided upon tcb was not unlocked in sctp_pcb.c
- Add error checking on arguments of sctp_sendx(3) to prevent it from
referencing a NULL pointer.
- Fix an error return of sctp_sendx(3), it was returing
ENOMEM not -1.
- Get assoc id was changed to use the sanctified socket api
method for getting a assoc id (PEER_ADDR_INFO instead of
PEER_ADDR_PARAMS).
- Fix it so a peeled off socket will get a proper error return
if it trys to send to a different address then it is connected to.
- Fix so that select_a_stream can avoid an endless loop that
could hang a caller.
- time_entered (state set time) was not being set in all cases
to the time we went established.
Approved by: re(ken smith)
- Adjust lock_profiling stubs semantic in the hard functions in order to be
more accurate and trustable
- Disable shared paths for lock_profiling. Actually, lock_profiling has a
subtle race which makes results caming from shared paths not completely
trustable. A macro stub (LOCK_PROFILING_SHARED) can be actually used for
re-enabling this paths, but is currently intended for developing use only.
- Use homogeneous names for automatic variables in hard functions regarding
lock_profiling
- Style fixes
- Add a CTASSERT for some flags building
Discussed with: kmacy, kris
Approved by: jeff (mentor)
Approved by: re
the 7.0 timeframe.
This is needed because I4B is not locked and NET_NEEDS_GIANT goes away.
The plan is to lock I4B and bring everything back for 7.1.
Approved by: re (kensmith)
This allocator uses a binary buddy system with a twist. First and
foremost, this allocator is required to support the implementation of
superpages. As a side effect, it enables a more robust implementation
of contigmalloc(9). Moreover, this reimplementation of
contigmalloc(9) eliminates the acquisition of Giant by
contigmalloc(..., M_NOWAIT, ...).
The twist is that this allocator tries to reduce the number of TLB
misses incurred by accesses through a direct map to small, UMA-managed
objects and page table pages. Roughly speaking, the physical pages
that are allocated for such purposes are clustered together in the
physical address space. The performance benefits vary. In the most
extreme case, a uniprocessor kernel running on an Opteron, I measured
an 18% reduction in system time during a buildworld.
This allocator does not implement page coloring. The reason is that
superpages have much the same effect. The contiguous physical memory
allocation necessary for a superpage is inherently colored.
Finally, the one caveat is that this allocator does not effectively
support prezeroed pages. I hope this is temporary. On i386, this is
a slight pessimization. However, on amd64, the beneficial effects of
the direct-map optimization outweigh the ill effects. I speculate
that this is true in general of machines with a direct map.
Approved by: re
Please note that, this is currently considered as an
experimental feature so there could be some rough
edges. Consult http://wiki.freebsd.org/TMPFS for
more information.
For now, connect tmpfs to build on i386 and amd64
architectures only. Please let us know if you have
success with other platforms.
This work was developed by Julio M. Merino Vidal
for NetBSD as a SoC project; Rohit Jalan ported it
from NetBSD to FreeBSD. Howard Su and Glen Leeder
are worked on it to continue this effort.
Obtained from: NetBSD via p4
Submitted by: Howard Su (with some minor changes)
Approved by: re (kensmith)
- Fix so VRF's will clean themselves up when no references are around.
- Allow sctp_ifa to be passed into inpcb_bind, addr_mgmt_ep_sa to bypass
normal validation checks.
- turn auto-asconf off for subset bound sockets
- Moves all logging to use KTR. This gets rid of most
of the logging #ifdef's with a few exceptions reducing
the number of config options for SCTP.
tunnels, and was not MPSAFE. The code can be easily restored in the
event that someone with an IPX over IP tunnel configuration can work
with me to test patches.
This removes one of five remaining consumers of NET_NEEDS_GIANT.
Approved by: re (kensmith)
is expanded, size of expansion was not taken int consideration.
- Fix so vtag hash is 1 bigger so that it modulo's out
correctly, avoids a panic when restart with right modulo happens.
- do not dereference stcb when control->do_not_ref_stcb is set
- Fix up packet logging to not often use a lock and also to
add to options.
- Fix some logging option duplication in the sctputil.h
The entire code is wrapperd in #ifdef ... #endif so it won't harm
the actual implementation, but developers are encouraged to test it.
For arm, ia64, ppc, sparc64 and sun4v some work is still
needed, thus arch maintainers are encouraged to bring their arch on par
with respect to i386 and amd64.
Approved by: re (implicit?)
obtaining and releasing shared and exclusive locks. The algorithms for
manipulating the lock cookie are very similar to that rwlocks. This patch
also adds support for exclusive locks using the same algorithm as mutexes.
A new sx_init_flags() function has been added so that optional flags can be
specified to alter a given locks behavior. The flags include SX_DUPOK,
SX_NOWITNESS, SX_NOPROFILE, and SX_QUITE which are all identical in nature
to the similar flags for mutexes.
Adaptive spinning on select locks may be enabled by enabling the
ADAPTIVE_SX kernel option. Only locks initialized with the SX_ADAPTIVESPIN
flag via sx_init_flags() will adaptively spin.
The common cases for sx_slock(), sx_sunlock(), sx_xlock(), and sx_xunlock()
are now performed inline in non-debug kernels. As a result, <sys/sx.h> now
requires <sys/lock.h> to be included prior to <sys/sx.h>.
The new kernel option SX_NOINLINE can be used to disable the aforementioned
inlining in non-debug kernels.
The size of struct sx has changed, so the kernel ABI is probably greatly
disturbed.
MFC after: 1 month
Submitted by: attilio
Tested by: kris, pjd
- Fix missing initialization in kern_rwlock.c causing bogus times to be collected
- Move updates to the lock hash to after the lock is released for spin mutexes,
sleep mutexes, and sx locks
- Add new kernel build option LOCK_PROFILE_FAST - only update lock profiling
statistics when an acquisition is contended. This reduces the overhead of
LOCK_PROFILING to increasing system time by 20%-25% which on
"make -j8 kernel-toolchain" on a dual woodcrest is unmeasurable in terms
of wall-clock time. Contrast this to enabling lock profiling without
LOCK_PROFILE_FAST and I see a 5x-6x slowdown in wall-clock time.
Make PIM dynamically loadable by using encap_attach_func().
PIM may now be loaded into a GENERIC kernel.
Tested with: ports/net/pimdd && tcpreplay && wireshark
Reviewed by: Pavlin Radoslavov
partitioning class that supports multiple schemes. Current
schemes supported are APM (Apple Partition Map) and GPT.
Change all GEOM_APPLE anf GEOM_GPT options into GEOM_PART_APM
and GEOM_PART_GPT (resp).
The ctlreq interface supports verbs to create and destroy
partitioning schemes on a disk; to add, delete and modify
partitions; and to commit or undo changes made.
the newly added DEV_EISA. This is done so that these back-ends can
be compiled on platforms not providing in{b,w,l}()/out{b,w,l}() and
friends (but may wish to use them together with bus front-ends other
than the EISA one).
NOTES though, as ofw_syscons(4) doesn't properly interface with
syscons(4) regarding loading the font specified with SC_DFLT_FONT,
causing a kernel with both options SC_OFWFB and SC_NO_MODE_CHANGE
to not link.
lookup early. This has some performance implications and should not be
enabled by default, but might help greatly in certain setups. After some
more testing this could be turned into a sysctl.
Tested by: avatar
LOR ids: 17, 24, 32, 46, 191 (conceptual)
MFC after: 6 weeks
by default for sun4v where it is absolutely required.
This change moves the buffer from struct pcpu to the stack to avoid
using the critical section which created a LOR in a couple of cases
due to interaction with the tty code and kqueue. The LOR can't be
fixed with the critical section and the pcpu buffer can't be used
without the critical section.
Putting the buffer on the stack was my initial solution, but it was
pointed out that the stress on the stack might cause problems
depending on the call path. We don't have a way of creating tests
for those possible cases, so it's best to leave this as an option
for the time being. In time we may get enough data to enable this
option more generally.
way I intended due to licensing restrictions. I had intended
that it would be defaulted on, with opt-out possible for
companies that don't accept the CDDL. The FreeBSD GENERIC
kernel has to be entirely BSD licensed, so the only alternative
would have been to make KDTRACE an opt-in option. That isn't
a design I favour.
wait (time waited to acquire) and hold times for *all* kernel locks. If
the architecture has a system synchronized TSC, the profiling code will
use that - thereby minimizing profiling overhead. Large chunks of profiling
code have been moved out of line, the overhead measured on the T1 for when
it is compiled in but not enabled is < 1%.
Approved by: scottl (standing in for mentor rwatson)
Reviewed by: des and jhb
work is not just mine, but it is also the works of Peter Lei
and Michael Tuexen. They both are my two key other developers
working on the project.. and they need ata-boy's too:
****
peterlei@cisco.comtuexen@fh-muenster.de
****
I did do a make sysent which updated the
syscall's and sysproto.. I hope that is correct... without
it you don't build since we have new syscalls for SCTP :-0
So go out and look at the NOTES, add
option SCTP (make sure inet and inet6 are present too)
and play with SCTP.
I will see about comitting some test tools I have after I
figure out where I should place them. I also have a
lib (libsctp.a) that adds some of the missing socketapi
functions that I need to put into lib's.. I will talk
to George about this :-)
There may still be some 64 bit issues in here, none of
us have a 64 bit processor to test with yet.. Michael
may have a MAC but thats another beast too..
If you have a mac and want to use SCTP contact Michael
he maintains a web site with a loadable module with
this code :-)
Reviewed by: gnn
Approved by: gnn
other problems while labels were first being added to various kernel
objects. They have outlived their usefulness.
MFC after: 1 month
Suggested by: Christopher dot Vance at SPARTA dot com
Obtained from: TrustedBSD Project
in older versions of FreeBSD. This option is pointless as it is needed in just
about every interesting usage of forward that I have ever seen. It doesn't make
the system any safer and just wastes huge amounts of develper time
when the system doesn't behave as expected when code is moved from
4.x to 6.x It doesn't make
the system any safer and just wastes huge amounts of develper time
when the system doesn't behave as expected when code is moved from
4.x to 6.x or 7.x
Reviewed by: glebius
MFC after: 1 week
and pc98 MD files. Remove nodevice and nooption lines specific
to sio(4) from ia64, powerpc and sparc64 NOTES. There were no
such lines for arm yet.
sio(4) is usable on less than half the platforms, not counting
a future mips platform. Its presence in MI files is therefore
increasingly becoming a burden.
the sysctls. This saves a lot of space in the resulting kernel which is
important for embedded systems. This change was done in a ABI compatible
way. The pointer is still there, it just points to an empty string instead
of the description.
MFC After: 3 days
encryption. There are two functions, a bpf tap which has a basic header with
the SPI number which our current tcpdump knows how to display, and handoff to
pfil(9) for packet filtering.
Obtained from: OpenBSD
Based on: kern/94829
No objections: arch, net
MFC after: 1 month
in 1999, and there are changes to the sysctl names compared to PR,
according to that discussion. The description is in sys/conf/NOTES.
Lines in the GENERIC files are added in commented-out form.
I'll attach the test script I've used to PR.
PR: kern/14584
Submitted by: babkin
I picked it up again. The scheduler is forked from ULE, but the
algorithm to detect an interactive process is almost completely
different with ULE, it comes from Linux paper "Understanding the
Linux 2.6.8.1 CPU Scheduler", although I still use same word
"score" as a priority boost in ULE scheduler.
Briefly, the scheduler has following characteristic:
1. Timesharing process's nice value is seriously respected,
timeslice and interaction detecting algorithm are based
on nice value.
2. per-cpu scheduling queue and load balancing.
3. O(1) scheduling.
4. Some cpu affinity code in wakeup path.
5. Support POSIX SCHED_FIFO and SCHED_RR.
Unlike scheduler 4BSD and ULE which using fuzzy RQ_PPQ, the scheduler
uses 256 priority queues. Unlike ULE which using pull and push, the
scheduelr uses pull method, the main reason is to let relative idle
cpu do the work, but current the whole scheduler is protected by the
big sched_lock, so the benefit is not visible, it really can be worse
than nothing because all other cpu are locked out when we are doing
balancing work, which the 4BSD scheduelr does not have this problem.
The scheduler does not support hyperthreading very well, in fact,
the scheduler does not make the difference between physical CPU and
logical CPU, this should be improved in feature. The scheduler has
priority inversion problem on MP machine, it is not good for
realtime scheduling, it can cause realtime process starving.
As a result, it seems the MySQL super-smack runs better on my
Pentium-D machine when using libthr, despite on UP or SMP kernel.
for CBUS-PNP cards there) by default, as there are no amd64 and sparc64
machines with ISA slots and which therefore could make use of this code
known to exist. For sparc64 this additionally allows to get rid of the
compat shims for in{b,w,l}()/out{b,w,l}() etc and the associated hacks.
OK'ed by: imp, peter
- Linux ioctl support, with the other Linux changes MegaCli
will run if you mount linprocfs & linsysfs then set
sysctl compat.linux.osrelease=2.6.12 or similar. This works
on i386. It should work on amd64 but not well tested yet.
StoreLib may or may not work. Remember to kldload mfi_linux.
- Add in AEN (Async Event Notification) support so we can
get messages from the firmware when something happens.
Not all messages are in defined in event detail. Use
event_log to try to figure out what happened.
- Try to implement something like SIGIO for StoreLib. Since
mrmonitor doesn't work right I can't fully test it. StoreLib
works best with the rh9 base. In theory mrmonitor isn't
needed due to native driver support of AEN :-)
Now we can configure and monitor the RAID better.
Submitted by: IronPort Systems.
When porting FreeBSD to a new platform, one of the more useful things to do is
get mi_startup() to let you know which SYSINIT it's up to. Most people tend to
whack a printf in the SYSINIT loop to print the address of the function it's
about to call. Going one better, jhb made a version that uses DDB to look up
the name of the function and print that instead. This version is essentially
his with the addition of some ifdeffery to make it optional and to allow it to
work (although using only the function address, not the symbol) if you forgot
to enable DDB.
All the cool bits by: jhb
Approved by: scottl, rink, cognet, imp
the linux module, since it is not cross-platform
- move linprocfs from "files" and "options" to architecture specific files,
since it only makes sense to build this for those architectures, where we
also have a linuxolator
- disable the build of the linuxolator on our tier-2 architecture "Alpha":
* we don't have a linux_base port which supports Alpha and at the
same time is not outdated/obsoleted upstream/in a good condition/
currently working
* the upcomming new default linux base port is based upon Fedora
Core 3 (security support via http://www.fedoralegacy.org), which
isn't available for Alpha (like the current default linux base
port which is based upon Red Hat 8)
* nobody answered my request for testing it ~1 month ago on
current@ and alpha@ (it doesn't surprises me, see above)
* a SoC student wouldn't have to waste time on something which
nobody is willing to test
This does not remove the alpha specific MD files of the linuxolator yet.
Discussed on: arch (mostly silence)
Spiritual support by: scottl
o Properly use rman(9) to manage resources. This eliminates the
need to puc-specific hacks to rman. It also allows devinfo(8)
to be used to find out the specific assignment of resources to
serial/parallel ports.
o Compress the PCI device "database" by optimizing for the common
case and to use a procedural interface to handle the exceptions.
The procedural interface also generalizes the need to setup the
hardware (program chipsets, program clock frequencies).
o Eliminate the need for PUC_FASTINTR. Serdev devices are fast by
default and non-serdev devices are handled by the bus.
o Use the serdev I/F to collect interrupt status and to handle
interrupts across ports in priority order.
o Sync the PCI device configuration to include devices found in
NetBSD and not yet merged to FreeBSD.
o Add support for Quatech 2, 4 and 8 port UARTs.
o Add support for a couple dozen Timedia serial cards as found
in Linux.
This allows one to change the behavior of the driver pre-boot.
NOTE: This patch was made for DragonFly BSD by Sepherosa Ziehau.
PR: kern/94833
Submitted by: Devon H. O'Dell
Obtained from: DragonFly
MFC after: 1 month
end for isa(4).
o Add a seperate bus frontend for acpi(4) and allow ISA DMA for
it when ISA is configured in the kernel. This allows acpi(4)
attachments in non-ISA configurations, as is possible for ia64.
o Add a seperate bus frontend for pci(4) and detect known single
port parallel cards.
o Merge PC98 specific changes under pc98/cbus into the MI driver.
The changes are minor enough for conditional compilation and
in this form invites better abstraction.
o Have ppc(4) usabled on all platforms, now that ISA specifics
are untangled enough.
enabled by default in NETSMB and smbfs.ko.
With the most of modern SMB providers requiring encryption by
default, there is little sense left in keeping the crypto part
of NETSMB optional at the build time.
This will also return smbfs.ko to its former properties users
are rather accustomed to.
Discussed with: freebsd-stable, re (scottl)
Not objected by: bp, tjr (silence)
MFC after: 5 days
into a separate module. Accordingly, convert the option into a device
named similarly.
Note for MFC: Perhaps the option should stay in RELENG_6 for POLA reasons.
Suggested by: scottl
Reviewed by: cokane
MFC after: 5 days
option. We always build audit_syscalls.c so that the system call
stubs can return ENOSYS rather than the system call code
generating SIGSYS for the system calls. We are not yet ready to
add AUDIT to LINT, as the prototypes for system call arguments
won't be there until after the system calls for audit are added.
Much work from: wsalamon
Obtained from: TrustedBSD Project
It detects both: buffer underflows and buffer overflows bugs at runtime
(on free(9) and realloc(9)) and prints backtraces from where memory was
allocated and from where it was freed.
Tested by: kris
work by yar, thompsa and myself. The checksum offloading part also involves
work done by Mihail Balikov.
The most important changes:
o Instead of global linked list of all vlan softc use a per-trunk
hash. The size of hash is dynamically adjusted, depending on
number of entries. This changes struct ifnet, replacing counter
of vlans with a pointer to trunk structure. This change is an
improvement for setups with big number of VLANs, several interfaces
and several CPUs. It is a small regression for a setup with a single
VLAN interface.
An alternative to dynamic hash is a per-trunk static array with
4096 entries, which is a compile time option - VLAN_ARRAY. In my
experiments the array is not an improvement, probably because such
a big trunk structure doesn't fit into CPU cache.
o Introduce an UMA zone for VLAN tags. Since drivers depend on it,
the zone is declared in kern_mbuf.c, not in optional vlan(4) driver.
This change is a big improvement for any setup utilizing vlan(4).
o Use rwlock(9) instead of mutex(9) for locking. We are the first
ones to do this! :)
o Some drivers can do hardware VLAN tagging + hardware checksum
offloading. Add an infrastructure for this. Whenever vlan(4) is
attached to a parent or parent configuration is changed, the flags
on vlan(4) interface are updated.
In collaboration with: yar, thompsa
In collaboration with: Mihail Balikov <mihail.balikov interbgc.com>
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)
