Commit Graph

12 Commits

Author SHA1 Message Date
thorpej 36da248c07 Back out the following chagne:
http://mail-index.netbsd.org/source-changes/2003/05/08/0068.html

There were some side-effects that I didn't anticipate, and fixing them
is proving to be more difficult than I thought, do just eject for now.
Maybe one day we can look at this again.

Fixes PR kern/21517.
2003-05-10 21:10:23 +00:00
thorpej b77900c3c2 Simplify the way the bounds of the managed kernel virtual address
space is advertised to UVM by making virtual_avail and virtual_end
first-class exported variables by UVM.  Machine-dependent code is
responsible for initializing them before main() is called.  Anything
that steals KVA must adjust these variables accordingly.

This reduces the number of instances of this info from 3 to 1, and
simplifies the pmap(9) interface by removing the pmap_virtual_space()
function call, and removing two arguments from pmap_steal_memory().

This also eliminates some kludges such as having to burn kernel_map
entries on space used by the kernel and stolen KVA.

This also eliminates use of VM_{MIN,MAX}_KERNEL_ADDRESS from MI code,
this giving MD code greater flexibility over the bounds of the managed
kernel virtual address space if a given port's specific platforms can
vary in this regard (this is especially true of the evb* ports).
2003-05-08 18:13:12 +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 abb48c5b71 Protect prototypes, certain macros, and inlines from userland. 1999-06-21 17:25:11 +00:00
thorpej 0ff8d3ac1a Define a new kernel object type, "intrsafe", which are used for objects
which can be used in an interrupt context.  Use pmap_kenter*() and
pmap_kremove() only for mappings owned by these objects.

Fixes some locking protocol issues related to MP support, and eliminates
all of the pmap_enter vs. pmap_kremove inconsistencies.
1999-05-25 20:30:08 +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
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