Commit Graph

24 Commits

Author SHA1 Message Date
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
chs 11a9651c8f replace vm_page_t with struct vm_page *. 2001-05-26 21:27:10 +00:00
chs 3845302904 remove trailing whitespace. 2001-05-25 04:06:11 +00:00
chs dd82ad8e2c eliminate the VM_PAGER_* error codes in favor of the traditional E* codes.
the mapping is:

VM_PAGER_OK		        0
VM_PAGER_BAD		        <unused>
VM_PAGER_FAIL		        <unused>
VM_PAGER_PEND		        0 (see below)
VM_PAGER_ERROR		        EIO
VM_PAGER_AGAIN		        EAGAIN
VM_PAGER_UNLOCK		        EBUSY
VM_PAGER_REFAULT	        ERESTART

for async i/o requests, it used to be possible for the request to
be convert to sync, and the pager would return VM_PAGER_OK or VM_PAGER_PEND
to indicate whether the caller should perform post-i/o cleanup.
this is no longer allowed; pagers must now return 0 to indicate that
the async i/o was successfully started, and the caller never needs to
worry about doing the post-i/o cleanup.
2001-03-10 22:46:45 +00:00
chs aeda8d3b77 Initial integration of the Unified Buffer Cache project. 2000-11-27 08:39:39 +00:00
chs c29a1b4461 allow ports to override PAGER_MAP_SIZE in machine/vmparam.h.
some ports (such as arm32) don't have enough KVA for the
increased default size once the UBC mapping is also present.
2000-11-27 08:19:50 +00:00
chs b5142d6841 increase PAGER_MAP_SIZE to 16MB and move it to uvm_pager.h
since the alpha and mips pmaps use it.
2000-11-24 22:41:38 +00:00
chs f9fb6f5a55 g/c unused pager ops "asyncget" and "aiodone". 2000-11-24 20:34:01 +00:00
mrg 2f159a1bac remove/move more mach vm header files:
<vm/pglist.h> -> <uvm/uvm_pglist.h>
	<vm/vm_inherit.h> -> <uvm/uvm_inherit.h>
	<vm/vm_kern.h> -> into <uvm/uvm_extern.h>
	<vm/vm_object.h> -> nothing
	<vm/vm_pager.h> -> into <uvm/uvm_pager.h>

also includes a bunch of <vm/vm_page.h> include removals (due to redudancy
with <vm/vm.h>), and a scattering of other similar headers.
2000-06-26 14:20:25 +00:00
thorpej 655b21e17d Tell uvm_pagermapin() the direction of the I/O so that it can map
with only the protection that it needs.
2000-05-19 03:45:04 +00:00
chs 60a7a67f71 remove uvm_shareprot(). no longer needed since the demise of share maps. 2000-04-03 08:09:02 +00:00
chs 03a4ef3a79 remove the "shareprot" pagerop. it's not needed anymore since
share maps are long gone.
2000-04-03 07:35:23 +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
chs 16f0ca3612 add support for ``swapctl -d'' (removing swap space).
improve handling of i/o errors in swap space.

reviewed by:  Chuck Cranor
2000-01-11 06:57:49 +00:00
thorpej abb48c5b71 Protect prototypes, certain macros, and inlines from userland. 1999-06-21 17:25:11 +00:00
mrg a0139bc39d remove now >1 year old pre-release message. 1999-03-25 18:48:49 +00:00
cgd 37c88c58da after discussion with chuck, nuke pgo_attach from uvm_pagerops 1999-03-24 03:45:27 +00:00
eeh a2dd74ed79 Merge paddr_t changes into the main branch. 1998-08-13 02:10:37 +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