Commit Graph

88 Commits

Author SHA1 Message Date
Peter Wemm
8928d4404a Update for run queue code. 1999-08-19 00:15:27 +00:00
Alan Cox
d4da2dbae6 Fix the following problem:
When creating new processes (or performing exec), the new page
directory is initialized too early.  The kernel might grow before
p_vmspace is initialized for the new process.  Since pmap_growkernel
doesn't yet know about the new page directory, it isn't updated, and
subsequent use causes a failure.

The fix is (1) to clear p_vmspace early, to stop pmap_growkernel
from stomping on memory, and (2) to defer part of the initialization
of new page directories until p_vmspace is initialized.

PR:		kern/12378
Submitted by:	tegge
Reviewed by:	dfr
1999-07-21 18:02:27 +00:00
Alan Cox
6ea5bd80fe Remove some unused function and variable declarations. 1999-06-19 18:42:53 +00:00
Peter Wemm
637cae1dd4 Only use p->p_lock (manage by PHOLD()/PRELE()) - P_NOSWAP/P_PHYSIO is no
longer set.
1999-04-06 03:11:34 +00:00
Luoqi Chen
b1028ad122 Hide access to vmspace:vm_pmap with inline function vmspace_pmap(). This
is the preparation step for moving pmap storage out of vmspace proper.

Reviewed by:	Alan Cox	<alc@cs.rice.edu>
		Matthew Dillion	<dillon@apollo.backplane.com>
1999-02-19 14:25:37 +00:00
Julian Elischer
88c5ea4574 Enable Linux threads support by default.
This takes the conditionals out of the code that has been tested by
various people for a while.
ps and friends (libkvm) will need a recompile as some proc structure
changes are made.

Submitted by:	"Richard Seaman, Jr." <dick@tar.com>
1999-01-26 02:38:12 +00:00
Matthew Dillon
6de6079300 Removed low-memory blockages at fork. This is the wrong place to put
this sort of test.  We need to fix the low-memory handling in general.
1999-01-21 09:36:23 +00:00
Matthew Dillon
1c7c3c6a86 This is a rather large commit that encompasses the new swapper,
changes to the VM system to support the new swapper, VM bug
    fixes, several VM optimizations, and some additional revamping of the
    VM code.  The specific bug fixes will be documented with additional
    forced commits.  This commit is somewhat rough in regards to code
    cleanup issues.

Reviewed by:	"John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
Julian Elischer
dc9c271aa1 Changes to the LINUX_THREADS support to only allocate extra memory for
shared signal handling when there is shared signal handling being
used.

This removes the main objection to making the shared signal handling
a standard ability in rfork() and friends and 'unconditionalising'
this code. (i.e. the allocation of an extra 328 bytes per process).

Signal handling information remains in the U area until such a time as
it's reference count would be incremented to > 1. At that point a new
struct is malloc'd and maintained in KVM so that it can be shared between
the processes (threads) using it.

A function to check the reference count and move the struct back to the U
area when it drops back to 1 is also supplied. Signal information is
therefore now swapable for all processes that are not sharing that
information with other processes. THis should addres the concerns raised
by Garrett and others.

Submitted by:	"Richard Seaman, Jr." <dick@tar.com>
1999-01-07 21:23:50 +00:00
Julian Elischer
39fb8e6b3e Fix two bogons created by 'patch(1)' in my last commit. 1998-12-19 08:23:31 +00:00
Julian Elischer
6626c6045c Reviewed by: Luoqi Chen, Jordan Hubbard
Submitted by:	 "Richard Seaman, Jr." <lists@tar.com>
Obtained from:	linux :-)

Code to allow Linux Threads to run under FreeBSD.

By default not enabled
This code is dependent on the conditional
COMPAT_LINUX_THREADS (suggested by Garret)
This is not yet a 'real' option but will be within some number of hours.
1998-12-19 02:55:34 +00:00
David Greenman
6cde7a165f Fixed two potentially serious classes of bugs:
1) The vnode pager wasn't properly tracking the file size due to
   "size" being page rounded in some cases and not in others.
   This sometimes resulted in corrupted files. First noticed by
   Terry Lambert.
   Fixed by changing the "size" pager_alloc parameter to be a 64bit
   byte value (as opposed to a 32bit page index) and changing the
   pagers and their callers to deal with this properly.
2) Fixed a bogus type cast in round_page() and trunc_page() that
   caused some 64bit offsets and sizes to be scrambled. Removing
   the cast required adding casts at a few dozen callers.
   There may be problems with other bogus casts in close-by
   macros. A quick check seemed to indicate that those were okay,
   however.
1998-10-13 08:24:45 +00:00
Andrzej Bialecki
faa5f8d8da Make #define NO_SWAPPING a normal kernel config option.
Reviewed by:	jkh
1998-09-29 17:33:59 +00:00
Peter Dufault
917e476dad Reviewed by: msmith, bde long ago
POSIX.4 headers and sysctl variables.  Nothing should change
unless POSIX4 is defined or _POSIX_VERSION is set to 199309.
1998-03-04 10:27:00 +00:00
Eivind Eklund
303b270b0a Staticize. 1998-02-09 06:11:36 +00:00
Eivind Eklund
0b08f5f737 Back out DIAGNOSTIC changes. 1998-02-06 12:14:30 +00:00
John Dyson
95461b450d 1) Start using a cleaner and more consistant page allocator instead
of the various ad-hoc schemes.
2)	When bringing in UPAGES, the pmap code needs to do another vm_page_lookup.
3)	When appropriate, set the PG_A or PG_M bits a-priori to both avoid some
	processor errata, and to minimize redundant processor updating of page
	tables.
4)	Modify pmap_protect so that it can only remove permissions (as it
	originally supported.)  The additional capability is not needed.
5)	Streamline read-only to read-write page mappings.
6)	For pmap_copy_page, don't enable write mapping for source page.
7)	Correct and clean-up pmap_incore.
8)	Cluster initial kern_exec pagin.
9)	Removal of some minor lint from kern_malloc.
10)	Correct some ioopt code.
11)	Remove some dead code from the MI swapout routine.
12)	Correct vm_object_deallocate (to remove backing_object ref.)
13)	Fix dead object handling, that had problems under heavy memory load.
14)	Add minor vm_page_lookup improvements.
15)	Some pages are not in objects, and make sure that the vm_page.c can
	properly support such pages.
16)	Add some more page deficit handling.
17)	Some minor code readability improvements.
1998-02-05 03:32:49 +00:00
Eivind Eklund
47cfdb166d Turn DIAGNOSTIC into a new-style option. 1998-02-04 22:34:03 +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
John Dyson
3a2dc656bc Fix the prototype for swapout_procs();
Submitted by:	dima@best.net
1997-12-11 02:10:55 +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
Poul-Henning Kamp
4a11ca4e29 Remove a bunch of variables which were unused both in GENERIC and LINT.
Found by:	-Wunused
1997-11-07 08:53:44 +00:00
Bruce Evans
79624e2147 Removed unused #includes. 1997-09-01 03:17:34 +00:00
Bruce Evans
b1037dcd53 #include <machine/limits.h> explicitly in the few places that it is required. 1997-08-21 20:33:42 +00:00
Peter Wemm
e108835bbc Unused variable (upobj is now purely handled within pmap) 1997-04-14 03:40:42 +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
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
Bruce Evans
16a02c1105 Removed redundant spl0()'s from kernel processes. They were work-arounds
for a bug in fork().
1997-01-15 19:05:08 +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
bc0d333478 EEEK!!! useracc and kernacc didn't lock their respective
maps.  Additionally, eliminate the map->hint distortion
associated with useracc.  That may/may-not be the "right"
thing to do -- but time will tell.
Submitted by:	Partially by Alan Cox <alc@cs.rice.edu>
1996-12-30 03:56:11 +00:00
Joerg Wunsch
e9822d926c Make DFLDSIZ and MAXDSIZ fully-supported options.
"Don't forget to do a ``make depend''" :-)
1996-12-22 23:17:09 +00:00
John Dyson
a669a6e9a9 Make processes waken up eligible for immediate swap-in. 1996-10-17 02:58:20 +00:00
John Dyson
675878e732 Move much of the machine dependent code from vm_glue.c into
pmap.c.  Along with the improved organization, small proc fork
performance is now about 5%-10% faster.
1996-10-15 03:16:45 +00:00
Bruce Evans
dd106ca742 Removed iprintf(). It was copied to db_iprintf() in ddb. 1996-09-15 11:24:21 +00:00
John Dyson
a6e6bcc5f4 Properly set the PG_MAPPED and PG_WRITEABLE flags. This fixes some potential
problems with vm_map_remove/vm_map_delete.
1996-07-02 02:08:02 +00:00
John Dyson
877329e059 Make -current consistant with -stable regarding time that a process
sleeps before being swapped out.  The time is increased from 4 secs to
10 secs.  Originally I had decreased it from 20 to 4, but that is a bit
severe.  20 is too long though.
1996-06-30 21:16:18 +00:00
John Dyson
f35329ac0f This commit is dual-purpose, to fix more of the pageout daemon
queue corruption problems, and to apply Gary Palmer's code cleanups.
David Greenman helped with these problems also.  There is still
a hang problem using X in small memory machines.
1996-05-31 00:38:04 +00:00
John Dyson
b18bfc3da7 This set of commits to the VM system does the following, and contain
contributions or ideas from Stephen McKay <syssgm@devetir.qld.gov.au>,
Alan Cox <alc@cs.rice.edu>, David Greenman <davidg@freebsd.org> and me:

	More usage of the TAILQ macros.  Additional minor fix to queue.h.
	Performance enhancements to the pageout daemon.
		Addition of a wait in the case that the pageout daemon
		has to run immediately.
		Slightly modify the pageout algorithm.
	Significant revamp of the pmap/fork code:
		1) PTE's and UPAGES's are NO LONGER in the process's map.
		2) PTE's and UPAGES's reside in their own objects.
		3) TOTAL elimination of recursive page table pagefaults.
		4) The page directory now resides in the PTE object.
		5) Implemented pmap_copy, thereby speeding up fork time.
		6) Changed the pv entries so that the head is a pointer
		   and not an entire entry.
		7) Significant cleanup of pmap_protect, and pmap_remove.
		8) Removed significant amounts of machine dependent
		   fork code from vm_glue.  Pushed much of that code into
		   the machine dependent pmap module.
		9) Support more completely the reuse of already zeroed
		   pages (Page table pages and page directories) as being
		   already zeroed.
	Performance and code cleanups in vm_map:
		1) Improved and simplified allocation of map entries.
		2) Improved vm_map_copy code.
		3) Corrected some minor problems in the simplify code.
	Implemented splvm (combo of splbio and splimp.)  The VM code now
		seldom uses splhigh.
	Improved the speed of and simplified kmem_malloc.
	Minor mod to vm_fault to avoid using pre-zeroed pages in the case
		of objects with backing objects along with the already
		existant condition of having a vnode.  (If there is a backing
		object, there will likely be a COW...  With a COW, it isn't
		necessary to start with a pre-zeroed page.)
	Minor reorg of source to perhaps improve locality of ref.
1996-05-18 03:38:05 +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
John Dyson
d3a3498598 Reinstitute the map lock for processes being swapped out. This
is needed because of the vm_fault used to bring the page table page
for the kernel stack (UPAGES) back in.  The consequence of the
previous incorrect change was a system hang.
1996-04-09 04:36:58 +00:00
John Dyson
b5cfb15fad Map lock checks not needed anymore for swapping out. We don't use
map operations for it anymore.  Certain deadlocks should never happen
anymore.
1996-04-08 03:42:01 +00:00
Bruce Evans
6ffde942bf Removed never-used #includes of <machine/cpu.h>. Many were apparently
copied from bad examples.
1996-04-07 17:39:28 +00:00
John Dyson
030ad08012 Fixed a problem that the UPAGES of a process were being run down
in a suboptimal manner.  I had also noticed some panics that appeared
to be at least superficially caused by this problem.  Also, included
are some minor mods to support more general handling of page table page
faulting.  More details in a future commit.
1996-04-03 05:23:44 +00:00
Jeffrey Hsu
1b67ec6de9 For Lite2: proc LIST changes.
Reviewed by:	 davidg & bde
1996-03-11 06:11:43 +00:00
John Dyson
9ea857084d Delay forking a process until there are more pages available. It was
possible to deadlock with the low threshold that we had used.
1996-03-09 06:57:53 +00:00
John Dyson
de5f6a7765 1) Eliminate unnecessary bzero of UPAGES.
2) Eliminate unnecessary copying of pages during/after forks.
3) Add user map simplification.
1996-03-02 02:54:24 +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
David Greenman
5afce28270 Add a "NO_SWAPPING" option to disable swapping. This was originally done
to help diagnose a problem on wcarchive (where the kernel stack was
sometimes not present), but is useful in its own right since swapping
actually reduces performance on some systems (such as wcarchive).
Note: swapping in this context means making the U pages pageable and has
nothing to do with generic VM paging, which is unaffected by this option.

Reviewed by:	 <dyson>
1996-02-22 10:57:37 +00:00