Only turn preemption for 4bsd.
it's still poison for ULE.

Give the 4bsd scheduler the ability to wake up idle processors
when there is new work to be done.

MFC after: 5 days

Turn off PREEMPTION by default while it gets debugged. It's been causing
4 weeks of problems including deadlocks and instant panics. Note that the
real bugs are likely in the scheduler.

Implement preemption of kernel threads natively in the scheduler rather
than as one-off hacks in various other parts of the kernel:
- Add a function maybe_preempt() that is called from sched_add() to

Implement preemption of kernel threads natively in the scheduler rather
than as one-off hacks in various other parts of the kernel:
- Add a function maybe_preempt() that is called from sched_add() to
determine if a thread about to be added to a run queue should be
preempted to directly. If it is not safe to preempt or if the new
thread does not have a high enough priority, then the function returns
false and sched_add() adds the thread to the run queue. If the thread
should be preempted to but the current thread is in a nested critical
section, then the flag TDF_OWEPREEMPT is set and the thread is added
to the run queue. Otherwise, mi_switch() is called immediately and the
thread is never added to the run queue since it is switch to directly.
When exiting an outermost critical section, if TDF_OWEPREEMPT is set,
then clear it and call mi_switch() to perform the deferred preemption.
- Remove explicit preemption from ithread_schedule() as calling
setrunqueue() now does all the correct work. This also removes the
do_switch argument from ithread_schedule().
- Do not use the manual preemption code in mtx_unlock if the architecture
supports native preemption.
- Don't call mi_switch() in a loop during shutdown to give ithreads a
chance to run if the architecture supports native preemption since
the ithreads will just preempt DELAY().
- Don't call mi_switch() from the page zeroing idle thread for
architectures that support native preemption as it is unnecessary.
- Native preemption is enabled on the same archs that supported ithread
preemption, namely alpha, i386, and amd64.

This change should largely be a NOP for the default case as committed
except that we will do fewer context switches in a few cases and will
avoid the run queues completely when preempting.

Approved by: scottl (with his re@ hat)

show more ...

Remove advertising clause from University of California Regent's
license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson

Migrate the thread stack management functions from the machine-dependent
to the machine-independent parts of the VM. At the same time, this
introduces vm object locking for the non-i386 platforms.

Migrate the thread stack management functions from the machine-dependent
to the machine-independent parts of the VM. At the same time, this
introduces vm object locking for the non-i386 platforms.

Two details:

1. KSTACK_GUARD has been removed in favor of KSTACK_GUARD_PAGES. The
different machine-dependent implementations used various combinations
of KSTACK_GUARD and KSTACK_GUARD_PAGES. To disable guard page, set
KSTACK_GUARD_PAGES to 0.

2. Remove the (unnecessary) clearing of PG_ZERO in vm_thread_new. In
5.x, (but not 4.x,) PG_ZERO can only be set if VM_ALLOC_ZERO is passed
to vm_page_alloc() or vm_page_grab().

show more ...

- Add support for PAE and more than 4 gigs of ram on x86, dependent on the
kernel opition 'options PAE'. This will only work with device drivers which
either use busdma, or are able to handle 64

- Add support for PAE and more than 4 gigs of ram on x86, dependent on the
kernel opition 'options PAE'. This will only work with device drivers which
either use busdma, or are able to handle 64 bit physical addresses.

Thanks to Lanny Baron from FreeBSD Systems for the loan of a test machine
with 6 gigs of ram.

Sponsored by: DARPA, Network Associates Laboratories, FreeBSD Systems

show more ...

- Add vm_paddr_t, a physical address type. This is required for systems
where physical addresses larger than virtual addresses, such as i386s
with PAE.
- Use this to represent physical addresses

- Add vm_paddr_t, a physical address type. This is required for systems
where physical addresses larger than virtual addresses, such as i386s
with PAE.
- Use this to represent physical addresses in the MI vm system and in the
i386 pmap code. This also changes the paddr parameter to d_mmap_t.
- Fix printf formats to handle physical addresses >4G in the i386 memory
detection code, and due to kvtop returning vm_paddr_t instead of u_long.

Note that this is a name change only; vm_paddr_t is still the same as
vm_offset_t on all currently supported platforms.

Sponsored by: DARPA, Network Associates Laboratories
Discussed with: re, phk (cdevsw change)

show more ...

- Added macros NPGPTD, NBPTD, and NPDEPTD, for dealing with the size of the
page directory.
- Use these instead of the magic constants 1 or PAGE_SIZE where appropriate.
There are still numerous a

- Added macros NPGPTD, NBPTD, and NPDEPTD, for dealing with the size of the
page directory.
- Use these instead of the magic constants 1 or PAGE_SIZE where appropriate.
There are still numerous assumptions that the page directory is exactly
1 page.

Sponsored by: DARPA, Network Associates Laboratories

show more ...

Initiate deorbit burn for the i386-only a.out related support. Moves are
under way to move the remnants of the a.out toolchain to ports. As the
comment in src/Makefile said, this stuff is deprecate

Initiate deorbit burn for the i386-only a.out related support. Moves are
under way to move the remnants of the a.out toolchain to ports. As the
comment in src/Makefile said, this stuff is deprecated and one should not
expect this to remain beyond 4.0-REL. It has already lasted WAY beyond
that.

Notable exceptions:
gcc - I have not touched the a.out generation stuff there.
ldd/ldconfig - still have some code to interface with a.out rtld.
old as/ld/etc - I have not removed these yet, pending their move to ports.
some includes - necessary for ldd/ldconfig for now.

Tested on: i386 (extensively), alpha

show more ...

Reduce the maximum KVA reserved for swap meta structures from 70 to 32 MB.
Reduce the swap meta calculation by a factor of 2, it's still massive overkill.

X-MFC after: immediately

Move MI stuff out of MD param.h files.

It can all still be overridden in the MD files should need suddenly arise.

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is fu

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after: ha ha ha ha

show more ...

Optionize UPAGES for the i386. As part of this I split some of the low
level implementation stuff out of machine/globaldata.h to avoid exposing
UPAGES to lots more places. The end result is that we

Optionize UPAGES for the i386. As part of this I split some of the low
level implementation stuff out of machine/globaldata.h to avoid exposing
UPAGES to lots more places. The end result is that we can double
the kernel stack size with 'options UPAGES=4' etc.

This is mainly being done for the benefit of a MFC to RELENG_4 at some
point. -current doesn't really need this so much since each interrupt
runs on its own kstack.

show more ...

Limit the amount of KVM reserved for the buffer cache and for swap-meta
information. The default limits only effect machines with > 1GB of ram
and can be overriden with two new kernel conf variables

Limit the amount of KVM reserved for the buffer cache and for swap-meta
information. The default limits only effect machines with > 1GB of ram
and can be overriden with two new kernel conf variables VM_SWZONE_SIZE_MAX
and VM_BCACHE_SIZE_MAX, or with loader variables kern.maxswzone and
kern.maxbcache. This has the effect of leaving more KVM available for
sizing NMBCLUSTERS and 'maxusers' and should avoid tripups where a sysad
adds memory to a machine and then sees the kernel panic on boot due to
running out of KVM.

Also change the default swap-meta auto-sizing calculation to allocate half
of what it was previously allocating. The prior defaults were way too high.
Note that we cannot afford to run out of swap-meta structures so we still
stay somewhat conservative here.

show more ...

Fix CMSG and ALIGN macro usage.
Previously we had to include <machine/param.h> or <sys/param.h> bogusly
due to the fact that <sys/socket.h> CMSG macros needed the ALIGN macro,
which was defined in pa

Fix CMSG and ALIGN macro usage.
Previously we had to include <machine/param.h> or <sys/param.h> bogusly
due to the fact that <sys/socket.h> CMSG macros needed the ALIGN macro,
which was defined in param.h. However, including param.h was a disaster
for namespace pollution.
This solution, as contributed by shin a while ago, fixes it elegantly
by wrapping the definitions around some namespace pollution preventer
definitions.
This patch was long overdue.
This should allow any network programmer to use <sys/socket.h> as
before.

PR: 19971, 20530
Submitted by: Martin Kaeske <MartinKaeske@lausitz.net>
Mark Andrews <Mark.Andrews@nominum.com>
Patch submitted by: shin
Reviewed by: bde

show more ...

Implement write combining for crashdumps. This is useful when
write caching is disabled on both SCSI and IDE disks where large
memory dumps could take up to an hour to complete.

Taking an i386 scsi

Implement write combining for crashdumps. This is useful when
write caching is disabled on both SCSI and IDE disks where large
memory dumps could take up to an hour to complete.

Taking an i386 scsi based system with 512MB of ram and timing (in
seconds) how long it took to complete a dump, the following results
were obtained:

Before: After:
WCE TIME WCE TIME
------------------ ------------------
1 141.820972 1 15.600111
0 797.265072 0 65.480465

Obtained from: Yahoo!
Reviewed by: peter

show more ...

Cleanup comment in machine/param.h regarding mbuf-related sizes, and get rid
of MCLOFSET, which does not appear to be used anywhere anymore, and if it is,
it probably shouldn't be.

Move MAXCPU from machine/smp.h to machine/param.h to fix breakage
with !SMP kernels. Also, replace NCPUS with MAXCPU since they are
redundant.

Change the mbuf size from 128 -> 256. Increasing the mbuf header size
caused some headers not to fit in MHLEN any more. This matches the
current size on the alpha, so it shouldn't cause problems.

Change the mbuf size from 128 -> 256. Increasing the mbuf header size
caused some headers not to fit in MHLEN any more. This matches the
current size on the alpha, so it shouldn't cause problems.

Problem observed by: Geoff Rehmet <geoff@is.co.za>
Originally suggested by: shin

show more ...

Reclaim UPAGES_HOLE (8k) that was chopped out of process address space.
The UPAGES have not been there since Jan '96, but the hole was preserved
for BSD/OS binary compatability. This has been fixed

Reclaim UPAGES_HOLE (8k) that was chopped out of process address space.
The UPAGES have not been there since Jan '96, but the hole was preserved
for BSD/OS binary compatability. This has been fixed other ways (%ebx
now has a pointer to PS_STRINGS), and the stack is nowhere near where
it used to be so this hack isn't required anymore.

show more ...

Back out a portion of the last commit. DFLTPHYS and MAXPHYS cannot
be set by a kernel conf option due to the struct buf structural
dependancy (sizing of b_pages[]) creating a conflict with m

Back out a portion of the last commit. DFLTPHYS and MAXPHYS cannot
be set by a kernel conf option due to the struct buf structural
dependancy (sizing of b_pages[]) creating a conflict with modules
(which are not compiled with kernel config options overrides).

We'll be able to sysctl these two later on when the buffer subsystem
is revamped.

show more ...

Change default block size for user VBLK device access from 2K to PAGE_SIZE
(4K on an i386, 8K on an alpha).

Make BLKDEV_IOSIZE, DFLTPHYS, and MAXPHYS kernel-configurable.

$Id$ -> $FreeBSD$

Don't define MACHINE, MACHINE_ARCH, _MACHINE or _MACHINE_ARCH if
already defined. This allows for cross building to work because we
need to lie to make to tell it to use the target names rather than

Don't define MACHINE, MACHINE_ARCH, _MACHINE or _MACHINE_ARCH if
already defined. This allows for cross building to work because we
need to lie to make to tell it to use the target names rather than the
host names.

This should have no effect on either architecture. I've confirmed
that the intel build by make buildworld's for the past 3 months.

show more ...