Commit Graph

63 Commits

Author SHA1 Message Date
Alan Cox
49a2507bd1 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().
2003-06-14 23:23:55 +00:00
Alan Cox
89f4fca265 Move the *_new_altkstack() and *_dispose_altkstack() functions out of the
various pmap implementations into the machine-independent vm.  They were
all identical.
2003-06-14 06:20:25 +00:00
Jake Burkholder
227f9a1c58 - 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)
2003-03-25 00:07:06 +00:00
Alfred Perlstein
c3dfdfd132 use 'void *' instead of 'caddr_t' for useracc, kernacc, vslock and vsunlock. 2003-01-21 11:34:57 +00:00
Alan Cox
ef594d3186 o Merge vm_fault_wire() and vm_fault_user_wire() by adding a new parameter,
user_wire.
2002-07-24 19:47:56 +00:00
Peter Wemm
3ebc124838 Infrastructure tweaks to allow having both an Elf32 and an Elf64 executable
handler in the kernel at the same time.  Also, allow for the
exec_new_vmspace() code to build a different sized vmspace depending on
the executable environment.  This is a big help for execing i386 binaries
on ia64.   The ELF exec code grows the ability to map partial pages when
there is a page size difference, eg: emulating 4K pages on 8K or 16K
hardware pages.

Flesh out the i386 emulation support for ia64.  At this point, the only
binary that I know of that fails is cvsup, because the cvsup runtime
tries to execute code in pages not marked executable.

Obtained from:  dfr (mostly, many tweaks from me).
2002-07-20 02:56:12 +00:00
Peter Wemm
a136efe9b6 Collect all the (now equivalent) pmap_new_proc/pmap_dispose_proc/
pmap_swapin_proc/pmap_swapout_proc functions from the MD pmap code
and use a single equivalent MI version.  There are other cleanups
needed still.

While here, use the UMA zone hooks to keep a cache of preinitialized
proc structures handy, just like the thread system does.  This eliminates
one dependency on 'struct proc' being persistent even after being freed.
There are some comments about things that can be factored out into
ctor/dtor functions if it is worth it.  For now they are mostly just
doing statistics to get a feel of how it is working.
2002-07-07 23:05:27 +00:00
Alan Cox
aa4d062142 o Eliminate the use of grow_stack() and useracc() from sendsig(), osendsig(),
and osf1_sendsig().
 o Eliminate the prototype for the MD grow_stack() now that it has been removed
   from all platforms.
2002-04-05 00:52:15 +00:00
Alan Cox
433b72aa12 Remove an unused prototype. 2002-03-26 05:30:59 +00:00
Alfred Perlstein
11caded34f Remove __P. 2002-03-19 22:20:14 +00:00
Eivind Eklund
a128794977 - Remove a number of extra newlines that do not belong here according to
style(9)
- Minor space adjustment in cases where we have "( ", " )", if(), return(),
  while(), for(), etc.
- Add /* SYMBOL */ after a few #endifs.

Reviewed by:	alc
2002-03-10 21:52:48 +00:00
Julian Elischer
079b7badea Pre-KSE/M3 commit.
this is a low-functionality change that changes the kernel to access the main
thread of a process via the linked list of threads rather than
assuming that it is embedded in the process. It IS still embeded there
but remove all teh code that assumes that in preparation for the next commit
which will actually move it out.

Reviewed by: peter@freebsd.org, gallatin@cs.duke.edu, benno rice,
2002-02-07 20:58:47 +00:00
Alfred Perlstein
582ec34cd8 Fix a race with free'ing vmspaces at process exit when vmspaces are
shared.

Also introduce vm_endcopy instead of using pointer tricks when
initializing new vmspaces.

The race occured because of how the reference was utilized:
  test vmspace reference,
  possibly block,
  decrement reference

When sharing a vmspace between multiple processes it was possible
for two processes exiting at the same time to test the reference
count, possibly block and neither one free because they wouldn't
see the other's update.

Submitted by: green
2002-02-05 21:23:05 +00:00
Ian Dowse
0eb6ce3169 Move the code that computes the system load average from vm_meter.c
to kern_synch.c in preparation for adding some jitter to the
inter-sample time.

Note that the "vm.loadavg" sysctl still lives in vm_meter.c which
isn't the right place, but it is appropriate for the current (bad)
name of that sysctl.

Suggested by:	jhb (some time ago)
Reviewed by:	bde
2001-10-20 13:10:43 +00:00
Julian Elischer
b40ce4165d 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
2001-09-12 08:38:13 +00:00
Peter Wemm
eb30c1c0b9 Rip some well duplicated code out of cpu_wait() and cpu_exit() and move
it to the MI area.  KSE touched cpu_wait() which had the same change
replicated five ways for each platform.  Now it can just do it once.
The only MD parts seemed to be dealing with fpu state cleanup and things
like vm86 cleanup on x86.  The rest was identical.

XXX: ia64 and powerpc did not have cpu_throw(), so I've put a functional
stub in place.

Reviewed by:	jake, tmm, dillon
2001-09-10 04:28:58 +00:00
Poul-Henning Kamp
7de472559c Remove unused 3rd argument from vsunlock() which abused B_WRITE. 2000-03-13 10:47:24 +00:00
Peter Wemm
c447342094 Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot).  This is consistant with the other
BSD's who made this change quite some time ago.  More commits to come.
1999-12-29 05:07:58 +00:00
Alan Cox
98b5130932 Remove unused declarations. 1999-11-08 00:53:34 +00:00
Matthew Dillon
4cc712004c Fix bug in pipe code relating to writes of mmap'd but illegal address
spaces which cross a segment boundry in the page table.  pmap_kextract()
    is not designed for access to the user space portion of the page
    table and cannot handle the null-page-directory-entry case.

    The fix is to have vm_fault_quick() return a success or failure which
    is then used to avoid calling pmap_kextract().
1999-09-20 19:08:48 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Dmitrij Tejblum
a839bdc8af Add a function kmem_alloc_nofault() - same as kmem_alloc_pageable(), but
create a nofault entry. It will be used to allocate kmem for upages.

(I am not too happy with all this, but it's better than nothing).
1999-06-08 17:03:28 +00:00
Peter Wemm
b8df55a044 Move the declaration of faultin() from the vm headers to proc.h, since
it is now referenced from a macro there (PHOLD()).
1999-04-13 19:17:15 +00:00
Julian Elischer
2907af2a96 Mostly remove the VM_STACK OPTION.
This changes the definitions of a few items so that structures are the
same whether or not the option itself is enabled. This allows
people to enable and disable the option without recompilng the world.

As the author says:

|I ran into a problem pulling out the VM_STACK option.  I was aware of this
|when I first did the work, but then forgot about it.  The VM_STACK stuff
|has some code changes in the i386 branch.  There need to be corresponding
|changes in the alpha branch before it can come out completely.

what is done:
|
|1) Pull the VM_STACK option out of the header files it appears in.  This
|really shouldn't affect anything that executes with or without the rest
|of the VM_STACK patches.  The vm_map_entry will then always have one
|extra element (avail_ssize).  It just won't be used if the VM_STACK
|option is not turned on.
|
|I've also pulled the option out of vm_map.c.  This shouldn't harm anything,
|since the routines that are enabled as a result are not called unless
|the VM_STACK option is enabled elsewhere.
|
|2) Add what appears to be appropriate code the the alpha branch, still
|protected behind the VM_STACK switch.  I don't have an alpha machine,
|so we would need to get some testers with alpha machines to try it out.
|
|Once there is some testing, we can consider making the change permanent
|for both i386 and alpha.
|
[..]
|
|Once the alpha code is adequately tested, we can pull VM_STACK out
|everywhere.
|

Submitted by:	"Richard Seaman, Jr." <dick@tar.com>
1999-01-26 02:49:52 +00:00
Julian Elischer
2267af789e Add (but don't activate) code for a special VM option to make
downward growing stacks more general.
Add (but don't activate) code to use the new stack facility
when running threads, (specifically the linux threads support).
This allows people to use both linux compiled linuxthreads, and also the
native FreeBSD linux-threads port.

The code is conditional on VM_STACK. Not using this will
produce the old heavily tested system.

Submitted by: Richard Seaman <dick@tar.com>
1999-01-06 23:05:42 +00:00
Doug Rabson
ecbb00a262 This commit fixes various 64bit portability problems required for
FreeBSD/alpha.  The most significant item is to change the command
argument to ioctl functions from int to u_long.  This change brings us
inline with various other BSD versions.  Driver writers may like to
use (__FreeBSD_version == 300003) to detect this change.

The prototype FreeBSD/alpha machdep will follow in a couple of days
time.
1998-06-07 17:13:14 +00:00
John Dyson
2d8acc0f4a VM level code cleanups.
1)	Start using TSM.
	Struct procs continue to point to upages structure, after being freed.
	Struct vmspace continues to point to pte object and kva space for kstack.
	u_map is now superfluous.
2)	vm_map's don't need to be reference counted.  They always exist either
	in the kernel or in a vmspace.  The vmspaces are managed by reference
	counts.
3)	Remove the "wired" vm_map nonsense.
4)	No need to keep a cache of kernel stack kva's.
5)	Get rid of strange looking ++var, and change to var++.
6)	Change more data structures to use our "zone" allocator.  Added
	struct proc, struct vmspace and struct vnode.  This saves a significant
	amount of kva space and physical memory.  Additionally, this enables
	TSM for the zone managed memory.
7)	Keep ioopt disabled for now.
8)	Remove the now bogus "single use" map concept.
9)	Use generation counts or id's for data structures residing in TSM, where
	it allows us to avoid unneeded restart overhead during traversals, where
	blocking might occur.
10)	Account better for memory deficits, so the pageout daemon will be able
	to make enough memory available (experimental.)
11)	Fix some vnode locking problems. (From Tor, I think.)
12)	Add a check in ufs_lookup, to avoid lots of unneeded calls to bcmp.
	(experimental.)
13)	Significantly shrink, cleanup, and make slightly faster the vm_fault.c
	code.  Use generation counts, get rid of unneded collpase operations,
	and clean up the cluster code.
14)	Make vm_zone more suitable for TSM.

This commit is partially as a result of discussions and contributions from
other people, including DG, Tor Egge, PHK, and probably others that I
have forgotten to attribute (so let me know, if I forgot.)

This is not the infamous, final cleanup of the vnode stuff, but a necessary
step.  Vnode mgmt should be correct, but things might still change, and
there is still some missing stuff (like ioopt, and physical backing of
non-merged cache files, debugging of layering concepts.)
1998-01-22 17:30:44 +00:00
Alexander Langer
651bb81717 caddr_t --> void * 1997-12-31 02:35:29 +00:00
John Dyson
ceb0cf87e8 Support an optional, sysctl enabled feature of idle process swapout. This
is apparently useful for large shell systems, or systems  with long running
idle processes.  To enable the feature:

	sysctl -w vm.swap_idle_enabled=1

Please note that some of the other vm sysctl variables have been renamed
to be more accurate.
Submitted by:	Much of it from Matt Dillon <dillon@best.net>
1997-12-06 02:23:36 +00:00
John Dyson
5856e12e69 Fully implement vfork. Vfork is now much much faster than even our
fork. (On my machine, fork is about 240usecs, vfork is 78usecs.)

Implement rfork(!RFPROC !RFMEM), which allows a thread to divorce its memory
	from the other threads of a group.

Implement rfork(!RFPROC RFCFDG), which closes all file descriptors, eliminating
	possible existing shares with other threads/processes.

Implement rfork(!RFPROC RFFDG), which divorces the file descriptors for a
	thread from the rest of the group.

Fix the case where a thread does an exec.  It is almost nonsense for a thread
	to modify the other threads address space by an exec, so we
	now automatically divorce the address space before modifying it.
1997-04-13 01:48:35 +00:00
Peter Wemm
a2a1c95c10 The biggie: Get rid of the UPAGES from the top of the per-process address
space. (!)

Have each process use the kernel stack and pcb in the kvm space.  Since
the stacks are at a different address, we cannot copy the stack at fork()
and allow the child to return up through the function call tree to return
to user mode - create a new execution context and have the new process
begin executing from cpu_switch() and go to user mode directly.
In theory this should speed up fork a bit.

Context switch the tss_esp0 pointer in the common tss.  This is a lot
simpler since than swithching the gdt[GPROC0_SEL].sd.sd_base pointer
to each process's tss since the esp0 pointer is a 32 bit pointer, and the
sd_base setting is split into three different bit sections at non-aligned
boundaries and requires a lot of twiddling to reset.

The 8K of memory at the top of the process space is now empty, and unmapped
(and unmappable, it's higher than VM_MAXUSER_ADDRESS).

Simplity the pmap code to manage process contexts, we no longer have to
double map the UPAGES, this simplifies and should measuably speed up fork().

The following parts came from John Dyson:

Set PG_G on the UPAGES that are now in kernel context, and invalidate
them when swapping them out.

Move the upages object (upobj) from the vmspace to the proc structure.

Now that the UPAGES (pcb and kernel stack) are out of user space, make
rfork(..RFMEM..) do what was intended by sharing the vmspace
entirely via reference counting rather than simply inheriting the mappings.
1997-04-07 07:16:06 +00:00
John Dyson
15cb98465f Correction to the prototype for vm_fault. 1997-04-06 02:30:56 +00:00
Peter Wemm
6875d25465 Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.
1997-02-22 09:48:43 +00:00
John Dyson
996c772f58 This is the kernel Lite/2 commit. There are some requisite userland
changes, so don't expect to be able to run the kernel as-is (very well)
without the appropriate Lite/2 userland changes.

The system boots and can mount UFS filesystems.

Untested: ext2fs, msdosfs, NFS
Known problems: Incorrect Berkeley ID strings in some files.
		Mount_std mounts will not work until the getfsent
		library routine is changed.

Reviewed by:	various people
Submitted by:	Jeffery Hsu <hsu@freebsd.org>
1997-02-10 02:22:35 +00:00
Jordan K. Hubbard
1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00
John Dyson
7aaaa4fd5d Implement closer-to POSIX mlock semantics. The major difference is
that we do allow mlock to span unallocated regions (of course, not
mlocking them.)  We also allow mlocking of RO regions (which the old
code couldn't.)  The restriction there is that once a RO region is
wired (mlocked), it cannot be debugged (or EVER written to.)

Under normal usage, the new mlock code will be a significant improvement
over our old stuff.
1996-12-14 17:54:17 +00:00
Bruce Evans
dd106ca742 Removed iprintf(). It was copied to db_iprintf() in ddb. 1996-09-15 11:24:21 +00:00
Bruce Evans
c7c34a24a3 Attached vm ddb commands show map', show vmochk', `show object',
`show vmopag', `show page' and `show pageq'.  Moved all vm ddb stuff
to the ends of the vm source files.

Changed printf() to db_printf(), `indent' to db_indent, and iprintf()
to db_iprintf() in ddb commands.  Moved db_indent and db_iprintf()
from vm to ddb.

vm_page.c:
Don't use __pure.  Staticized.

db_output.c:
Reduced page width from 80 to 79 to inhibit double spacing for long
lines (there are still some problems if words are printed across
column 79).
1996-09-14 11:54:59 +00:00
Poul-Henning Kamp
a8c5fef5e6 KGDB is dead. It may come back one day if somebody does it. 1996-05-02 09:34:51 +00:00
Peter Wemm
dabee6fecc kern_descrip.c: add fdshare()/fdcopy()
kern_fork.c: add the tiny bit of code for rfork operation.
kern/sysv_*: shmfork() takes one less arg, it was never used.
sys/shm.h: drop "isvfork" arg from shmfork() prototype
sys/param.h: declare rfork args.. (this is where OpenBSD put it..)
sys/filedesc.h: protos for fdshare/fdcopy.
vm/vm_mmap.c: add minherit code, add rounding to mmap() type args where
it makes sense.
vm/*: drop unused isvfork arg.

Note: this rfork() implementation copies the address space mappings,
it does not connect the mappings together.  ie: once the two processes
have split, the pages may be shared, but the address space is not. If one
does a mmap() etc, it does not appear in the other.  This makes it not
useful for pthreads, but it is useful in it's own right for having
light-weight threads in a static shared address space.

Obtained from: Original by Ron Minnich, extended by OpenBSD
1996-02-23 18:49:25 +00:00
John Dyson
dca5129987 Changed vm_fault_quick in vm_machdep.c to be global. Needed for
new pipe code.
1996-02-04 22:09:12 +00:00
Poul-Henning Kamp
f708ef1b9e Another mega commit to staticize things. 1995-12-14 09:55:16 +00:00
John Dyson
a316d390bd Changes to support 1Tb filesizes. Pages are now named by an
(object,index) pair instead of (object,offset) pair.
1995-12-11 04:58:34 +00:00
David Greenman
efeaf95a41 Untangled the vm.h include file spaghetti. 1995-12-07 12:48:31 +00:00
Poul-Henning Kamp
a9ad941c7a Move all the VM sysctl stuff home where it belongs. 1995-11-14 09:29:34 +00:00
Julian Elischer
2b14f991e6 Reviewed by: julian with quick glances by bruce and others
Submitted by:	terry (terry lambert)
This is  a composite of 3 patch sets submitted by terry.
they are:
New low-level init code that supports loadbal modules better
some cleanups in the namei code to help terry in 16-bit character support
some changes to the mount-root code to make it a little more
modular..

NOTE: mounting root off cdrom or NFS MIGHT be broken as I haven't been able
to test those cases..

certainly mounting root of disk still works just fine..
mfs should work but is untested. (tomorrows task)

The low level init stuff includes a total rewrite of init_main.c
to make it possible for new modules to have an init phase by simply
adding an entry to a TEXT_SET (or is it DATA_SET) list. thus a new module can
be added to the kernel without editing any other files other than the
'files' file.
1995-08-28 09:19:25 +00:00
David Greenman
24a1cce34f NOTE: libkvm, w, ps, 'top', and any other utility which depends on struct
proc or any VM system structure will have to be rebuilt!!!

Much needed overhaul of the VM system. Included in this first round of
changes:

1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages,
   haspage, and sync operations are supported. The haspage interface now
   provides information about clusterability. All pager routines now take
   struct vm_object's instead of "pagers".

2) Improved data structures. In the previous paradigm, there is constant
   confusion caused by pagers being both a data structure ("allocate a
   pager") and a collection of routines. The idea of a pager structure has
   escentially been eliminated. Objects now have types, and this type is
   used to index the appropriate pager. In most cases, items in the pager
   structure were duplicated in the object data structure and thus were
   unnecessary. In the few cases that remained, a un_pager structure union
   was created in the object to contain these items.

3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now
   be removed. For instance, vm_object_enter(), vm_object_lookup(),
   vm_object_remove(), and the associated object hash list were some of the
   things that were removed.

4) simple_lock's removed. Discussion with several people reveals that the
   SMP locking primitives used in the VM system aren't likely the mechanism
   that we'll be adopting. Even if it were, the locking that was in the code
   was very inadequate and would have to be mostly re-done anyway. The
   locking in a uni-processor kernel was a no-op but went a long way toward
   making the code difficult to read and debug.

5) Places that attempted to kludge-up the fact that we don't have kernel
   thread support have been fixed to reflect the reality that we are really
   dealing with processes, not threads. The VM system didn't have complete
   thread support, so the comments and mis-named routines were just wrong.
   We now use tsleep and wakeup directly in the lock routines, for instance.

6) Where appropriate, the pagers have been improved, especially in the
   pager_alloc routines. Most of the pager_allocs have been rewritten and
   are now faster and easier to maintain.

7) The pagedaemon pageout clustering algorithm has been rewritten and
   now tries harder to output an even number of pages before and after
   the requested page. This is sort of the reverse of the ideal pagein
   algorithm and should provide better overall performance.

8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup
   have been removed. Some other unnecessary casts have also been removed.

9) Some almost useless debugging code removed.

10) Terminology of shadow objects vs. backing objects straightened out.
    The fact that the vm_object data structure escentially had this
    backwards really confused things. The use of "shadow" and "backing
    object" throughout the code is now internally consistent and correct
    in the Mach terminology.

11) Several minor bug fixes, including one in the vm daemon that caused
    0 RSS objects to not get purged as intended.

12) A "default pager" has now been created which cleans up the transition
    of objects to the "swap" type. The previous checks throughout the code
    for swp->pg_data != NULL were really ugly. This change also provides
    the rudiments for future backing of "anonymous" memory by something
    other than the swap pager (via the vnode pager, for example), and it
    allows the decision about which of these pagers to use to be made
    dynamically (although will need some additional decision code to do
    this, of course).

13) (dyson) MAP_COPY has been deprecated and the corresponding "copy
    object" code has been removed. MAP_COPY was undocumented and non-
    standard. It was furthermore broken in several ways which caused its
    behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will
    continue to work correctly, but via the slightly different semantics
    of MAP_PRIVATE.

14) (dyson) Sharing maps have been removed. It's marginal usefulness in a
    threads design can be worked around in other ways. Both #12 and #13
    were done to simplify the code and improve readability and maintain-
    ability. (As were most all of these changes)

TODO:

1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing
   this will reduce the vnode pager to a mere fraction of its current size.

2) Rewrite vm_fault and the swap/vnode pagers to use the clustering
   information provided by the new haspage pager interface. This will
   substantially reduce the overhead by eliminating a large number of
   VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be
   improved to provide both a "behind" and "ahead" indication of
   contiguousness.

3) Implement the extended features of pager_haspage in swap_pager_haspage().
   It currently just says 0 pages ahead/behind.

4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps
   via a much more general mechanism that could also be used for disk
   striping of regular filesystems.

5) Do something to improve the architecture of vm_object_collapse(). The
   fact that it makes calls into the swap pager and knows too much about
   how the swap pager operates really bothers me. It also doesn't allow
   for collapsing of non-swap pager objects ("unnamed" objects backed by
   other pagers).
1995-07-13 08:48:48 +00:00
David Greenman
6306c897b5 swapout_threads() -> swapout_procs(). 1995-07-10 08:53:22 +00:00
David Greenman
a401ebbe32 Changed swap partition handling/allocation so that it doesn't
require specific partitions be mentioned in the kernel config
file ("swap on foo" is now obsolete).

From Poul-Henning:

The visible effect is this:

As default, unless
        options "NSWAPDEV=23"
is in your config, you will have four swap-devices.
You can swapon(2) any block device you feel like, it doesn't have
to be in the kernel config.

There is a performance/resource win available by getting the NSWAPDEV right
(but only if you have just one swap-device ??), but using that as default
would be too restrictive.

The invisible effect is that:

Swap-handling disappears from the $arch part of the kernel.
It gets a lot simpler (-145 lines) and cleaner.

Reviewed by:	John Dyson, David Greenman
Submitted by:	Poul-Henning Kamp, with minor changes by me.
1995-05-14 03:00:10 +00:00
David Greenman
ee3a64c992 Changed "handle" from type caddr_t to void *; "handle" is several different
types of pointers, and "char *" is a bad choice for the type.
1995-05-10 18:56:09 +00:00