Commit Graph

32 Commits

Author SHA1 Message Date
enami b7ac697dae s/than than/than/. 2002-11-08 02:05:16 +00:00
chs 64c6d1d2dc a whole bunch of changes to improve performance and robustness under load:
- remove special treatment of pager_map mappings in pmaps.  this is
   required now, since I've removed the globals that expose the address range.
   pager_map now uses pmap_kenter_pa() instead of pmap_enter(), so there's
   no longer any need to special-case it.
 - eliminate struct uvm_vnode by moving its fields into struct vnode.
 - rewrite the pageout path.  the pager is now responsible for handling the
   high-level requests instead of only getting control after a bunch of work
   has already been done on its behalf.  this will allow us to UBCify LFS,
   which needs tighter control over its pages than other filesystems do.
   writing a page to disk no longer requires making it read-only, which
   allows us to write wired pages without causing all kinds of havoc.
 - use a new PG_PAGEOUT flag to indicate that a page should be freed
   on behalf of the pagedaemon when it's unlocked.  this flag is very similar
   to PG_RELEASED, but unlike PG_RELEASED, PG_PAGEOUT can be cleared if the
   pageout fails due to eg. an indirect-block buffer being locked.
   this allows us to remove the "version" field from struct vm_page,
   and together with shrinking "loan_count" from 32 bits to 16,
   struct vm_page is now 4 bytes smaller.
 - no longer use PG_RELEASED for swap-backed pages.  if the page is busy
   because it's being paged out, we can't release the swap slot to be
   reallocated until that write is complete, but unlike with vnodes we
   don't keep a count of in-progress writes so there's no good way to
   know when the write is done.  instead, when we need to free a busy
   swap-backed page, just sleep until we can get it busy ourselves.
 - implement a fast-path for extending writes which allows us to avoid
   zeroing new pages.  this substantially reduces cpu usage.
 - encapsulate the data used by the genfs code in a struct genfs_node,
   which must be the first element of the filesystem-specific vnode data
   for filesystems which use genfs_{get,put}pages().
 - eliminate many of the UVM pagerops, since they aren't needed anymore
   now that the pager "put" operation is a higher-level operation.
 - enhance the genfs code to allow NFS to use the genfs_{get,put}pages
   instead of a modified copy.
 - clean up struct vnode by removing all the fields that used to be used by
   the vfs_cluster.c code (which we don't use anymore with UBC).
 - remove kmem_object and mb_object since they were useless.
   instead of allocating pages to these objects, we now just allocate
   pages with no object.  such pages are mapped in the kernel until they
   are freed, so we can use the mapping to find the page to free it.
   this allows us to remove splvm() protection in several places.

The sum of all these changes improves write throughput on my
decstation 5000/200 to within 1% of the rate of NetBSD 1.5
and reduces the elapsed time for "make release" of a NetBSD 1.5
source tree on my 128MB pc to 10% less than a 1.5 kernel took.
2001-09-15 20:36:31 +00:00
thorpej ae69446f0f Back out previous -- christos needs to update his lint(1). 2001-07-25 23:05:04 +00:00
christos 8228035453 fix non-portable bitmap warning. 2001-07-25 22:41:10 +00:00
wiz a9356936b4 seperate -> separate 2001-07-22 13:33:58 +00:00
thorpej c3cd2c3cfc Rather than using u_shorts, use u_ints and bitfields in the vm_page. This
provides us more flexibility with pageq-locked fields, and clarifies the
locking semantics for platforms which cannot address shorts.

From Ross Harvey.
2001-06-28 00:26:38 +00:00
chs 3845302904 remove trailing whitespace. 2001-05-25 04:06:11 +00:00
ross d8840def52 Expand on the locking notes comment with a XXX warning about u_short fields. 2001-05-16 00:16:01 +00:00
thorpej 31fafb678f Support dynamic sizing of the page color bins. We also support
dynamically re-coloring pages; as machine-dependent code discovers
the size of the system's caches, it may call uvm_page_recolor() with
the new number of colors to use.  If the new mumber of colors is
smaller (or equal to) the current number of colors, then uvm_page_recolor()
is a no-op.

The system defaults to one bucket if machine-dependent code does not
initialize uvmexp.ncolors before uvm_page_init() is called.

Note that the number of color bins should be initialized to something
reasonable as early as possible -- for many early memory allocations,
we live with the consequences of the page choice for the lifetime of
the boot.
2001-05-02 01:22:19 +00:00
thorpej 220bcf69ac Garbage-collect a comment that has not been applicable since Mach. 2001-05-01 03:01:18 +00:00
thorpej cf67ac7122 Per discussion w/ chuck and chuck, restructure the md page stuff
to use a structure called "vm_page_md", and use __HAVE_VM_PAGE_MD
and __HAVE_PMAP_PHYSSEG.
2001-05-01 02:19:13 +00:00
thorpej 2b27ac7a99 Add a VM_MDPAGE_MEMBERS macro that defines pmap-specific data for
each vm_page structure.  Add a VM_MDPAGE_INIT() macro to init this
data when pages are initialized by UVM.  These macros are mandatory,
but ports may #define them to nothing if they are not needed/used.

This deprecates struct pmap_physseg.  As a transitional measure,
allow a port to #define PMAP_PHYSSEG so that it can continue to
use it until its pmap is converted to use VM_MDPAGE_MEMBERS.

Use all this stuff to eliminate a lot of extra work in the Alpha
pmap module (it's smaller and faster now).  Changes to other pmap
modules will follow.
2001-04-29 22:44:31 +00:00
thorpej cda7baa0d5 Implement page coloring, using a round-robin bucket selection
algorithm (Solaris calls this "Bin Hopping").

This implementation currently relies on MD code to define a
constant defining the number of buckets.  This will change
reasonably soon (MD code will be able to dynamically size
the bucket array).
2001-04-29 04:23:20 +00:00
chs 1e651a1688 remove some more leftovers from Mach. 2000-12-28 08:24:55 +00:00
chs aeda8d3b77 Initial integration of the Unified Buffer Cache project. 2000-11-27 08:39:39 +00:00
mrg dd521daa8b clean up a comment. 2000-10-03 20:50:49 +00:00
mrg 88adda1288 more vm header file changes:
<vm/vm_extern.h> merged into <uvm/uvm_extern.h>
	<vm/vm_page.h> merged into <uvm/uvm_page.h>
	<vm/pmap.h> has become <uvm/uvm_pmap.h>

this leaves just <vm/vm.h> in NetBSD.
2000-06-27 09:00:14 +00:00
thorpej 9ec517a68e Changes necessary to implement pre-zero'ing of pages in the idle loop:
- Make page free lists have two actual queues: known-zero pages and
  pages with unknown contents.
- Implement uvm_pageidlezero().  This function attempts to zero up to
  the target number of pages until the target has been reached (currently
  target is `all free pages') or until whichqs becomes non-zero (indicating
  that a process is ready to run).
- Define a new hook for the pmap module for pre-zero'ing pages.  This is
  used to zero the pages using uncached access.  This allows us to zero
  as many pages as we want without polluting the cache.

In order to use this feature, each platform must add the appropropriate
glue in their idle loop.
2000-04-24 17:12:00 +00:00
kleink 6e5b64c8a0 Merge parts of chs-ubc2 into the trunk:
Add a new type voff_t (defined as a synonym for off_t) to describe offsets
into uvm objects, and update the appropriate interfaces to use it, the
most visible effect being the ability to mmap() file offsets beyond
the range of a vaddr_t.

Originally by Chuck Silvers; blame me for problems caused by merging this
into non-UBC.
2000-03-26 20:54:45 +00:00
thorpej abb48c5b71 Protect prototypes, certain macros, and inlines from userland. 1999-06-21 17:25:11 +00:00
thorpej 6eb9ee7cd8 - Change uvm_{lock,unlock}_fpageq() to return/take the previous interrupt
level directly, instead of making the caller wrap the calls in
  splimp()/splx().
- Add a comment documenting that interrupts that cause memory allocation
  must be blocked while the free page queue is locked.

Since interrupts must be blocked while this lock is asserted, tying them
together like this helps to prevent mistakes.
1999-05-24 19:10:57 +00:00
mrg a0139bc39d remove now >1 year old pre-release message. 1999-03-25 18:48:49 +00:00
eeh a2dd74ed79 Merge paddr_t changes into the main branch. 1998-08-13 02:10:37 +00:00
thorpej 7fd701e0fa Add support for multiple memory free lists. There is at least one
default free list, and 0 - N additional free list, in order of descending
priority.

A new page allocation function, uvm_pagealloc_strat(), has been added,
providing three page allocation strategies:

	- normal: high -> low priority free list walk, taking the
	  page off the first free list that has one.

	- only: attempt to allocate a page only from the specified free
	  list, failing if that free list has none available.

	- fallback: if `only' fails, fall back on `normal'.

uvm_pagealloc(...) is provided for normal use (and is a synonym for
uvm_pagealloc_strat(..., UVM_PGA_STRAT_NORMAL, 0); the free list argument
is ignored for the `normal' case).

uvm_page_physload() now specified which free list the pages will be
loaded onto.  This means that some platforms which have multiple physical
memory segments may define additional vm_physsegs if they wish to break
individual physical segments into differing priorities.

Machine-dependent code must define _at least_ the following constants
in <machine/vmparam.h>:

	VM_NFREELIST: the number of free lists the system will have

	VM_FREELIST_DEFAULT: the default freelist (should always be 0,
	but is defined in machdep code so that it's with all of the
	other free list-related constants).

Additional free list names may be defined by machine-dependent code, but
they will only be used by machine-dependent code (e.g. for loading the
vm_physsegs).
1998-07-08 04:28:27 +00:00
chuck 07c8bdc65f unstatic uvm_page_physload so pmap modules can use it too.
as requested by Eduardo E. Horvath
1998-05-28 15:31:31 +00:00
chuck e6da5a01e4 remove tmpwire arg from uvm_pagewire() -- it isn't needed anymore.
noted by chuck s.
1998-03-22 21:29:30 +00:00
mrg 8106d13596 KNF. 1998-03-09 00:58:55 +00:00
mrg d90485202c - add defopt's for UVM, UVMHIST and PMAP_NEW.
- remove unnecessary UVMHIST_DECL's.
1998-02-10 14:08:44 +00:00
perry 021fdb646a add/cleanup multiple inclusion protection. 1998-02-10 02:34:17 +00:00
mrg 1f6b921cf7 restore rcsids 1998-02-07 11:07:38 +00:00
thorpej 9eb328b495 RCS ID police. 1998-02-06 22:26:13 +00:00
mrg f2caacc717 initial import of the new virtual memory system, UVM, into -current.
UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code.  i provided some help
getting swap and paging working, and other bug fixes/ideas.  chuck
silvers <chuq@chuq.com> also provided some other fixes.

this is the UVM kernel code portion.


this will be KNF'd shortly.  :-)
1998-02-05 06:25:08 +00:00