Make ZONE_DMA32 optional
- Add #ifdefs around ZONE_DMA32 specific code and definitions.
- Add CONFIG_ZONE_DMA32 config option and use that for x86_64
that alone needs this zone.
- Remove the use of CONFIG_DMA_IS_DMA32 and CONFIG_DMA_IS_NORMAL
for ia64 and fix up the way per node ZVCs are calculated.
- Fall back to prior GFP_ZONEMASK of 0x03 if there is no
DMA32 zone.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use enum for zones and reformat zones dependent information
Add comments explaning the use of zones and add a zones_t type for zone
numbers.
Line up information that will be #ifdefd by the following patches.
[akpm@osdl.org: comment cleanups]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
page allocator ZONE_HIGHMEM fixups
1. We do not need to do an #ifdef in si_meminfo since both counters
in use are zero if !CONFIG_HIGHMEM.
2. Add #ifdef in si_meminfo_node instead to avoid referencing zone
information for ZONE_HIGHMEM if we do not have HIGHMEM
(may not be there after the following patches).
3. Replace the use of ZONE_HIGHMEM with MAX_NR_ZONES in build_zonelists_node
4. build_zonelists_node: Remove BUG_ON for ZONE_HIGHMEM. Zone will
be optional soon and thus BUG_ON cannot be triggered anymore.
5. init_free_area_core: Replace a use of ZONE_HIGHMEM with NR_MAX_ZONES.
[akpm@osdl.org: cleanups]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Move totalhigh_pages and nr_free_highpages() into highmem.c/.h
Move the totalhigh_pages definition into highmem.c/.h. Move the
nr_free_highpages function into highmem.c
[yoichi_yuasa@tripeaks.co.jp: build fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Do not display HIGHMEM memory sizes if CONFIG_HIGHMEM is not set.
Make HIGHMEM dependent texts and make display of highmem counters optional
Some texts are depending on CONFIG_HIGHMEM.
Remove those strings and remove the display of highmem counter values if
CONFIG_HIGHMEM is not set.
[akpm@osdl.org: remove some ifdefs]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix array initialization in lots of arches
The number of zones may now be reduced from 4 to 2 for many arches. Fix the
array initialization for the zones array for all architectures so that it is
not initializing a fixed number of elements.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I keep seeing zones on various platforms that are never used and wonder why we
compile support for them into the kernel. Counters show up for HIGHMEM and
DMA32 that are alway zero.
This patch allows the removal of ZONE_DMA32 for non x86_64 architectures and
it will get rid of ZONE_HIGHMEM for arches not using highmem (like 64 bit
architectures). If an arch does not define CONFIG_HIGHMEM then ZONE_HIGHMEM
will not be defined. Similarly if an arch does not define CONFIG_ZONE_DMA32
then ZONE_DMA32 will not be defined.
No current architecture uses all the 4 zones (DMA,DMA32,NORMAL,HIGH) that we
have now. The patchset will reduce the number of zones for all platforms.
On many platforms that do not have DMA32 or HIGHMEM this will reduce the
number of zones by 50%. F.e. ia64 only uses DMA and NORMAL.
Large amounts of memory can be saved for larger systemss that may have a few
hundred NUMA nodes.
With ZONE_DMA32 and ZONE_HIGHMEM support optional MAX_NR_ZONES will be 2 for
many non i386 platforms and even for i386 without CONFIG_HIGHMEM set.
Tested on ia64, x86_64 and on i386 with and without highmem.
The patchset consists of 11 patches that are following this message.
One could go even further than this patchset and also make ZONE_DMA optional
because some platforms do not need a separate DMA zone and can do DMA to all
of memory. This could reduce MAX_NR_ZONES to 1. Such a patchset will
hopefully follow soon.
This patch:
Fix strange uses of MAX_NR_ZONES
Sometimes we use MAX_NR_ZONES - x to refer to a zone. Make that explicit.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It fixes various coding style issues, specially when spaces are useless. For
example '*' go next to the function name.
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It also creates get_mapsize() helper in order to make the code more readable
when it calculates the boot bitmap size.
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
__init in headers is pretty useless because the compiler doesn't check it, and
they get out of sync relatively frequently. So if you see an __init in a
header file, it's quite unreliable and you need to check the definition
anyway.
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Address a long standing issue of booting with an initrd on an i386 numa
system. Currently (and always) the numa kva area is mapped into low memory
by finding the end of low memory and moving that mark down (thus creating
space for the kva). The issue with this is that Grub loads initrds into
this similar space so when the kernel check the initrd it finds it outside
max_low_pfn and disables it (it thinks the initrd is not mapped into usable
memory) thus initrd enabled kernels can't boot i386 numa :(
My solution to the problem just converts the numa kva area to use the
bootmem allocator to save it's area (instead of moving the end of low
memory). Using bootmem allows the kva area to be mapped into more diverse
addresses (not just the end of low memory) and enables the kva area to be
mapped below the initrd if present.
I have tested this patch on numaq(no initrd) and summit(initrd) i386 numa
based systems.
[akpm@osdl.org: cleanups]
Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch makes the following needlessly global functions static:
- slab.c: kmem_find_general_cachep()
- swap.c: __page_cache_release()
- vmalloc.c: __vmalloc_node()
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With the tracking of dirty pages properly done now, msync doesn't need to scan
the PTEs anymore to determine the dirty status.
From: Hugh Dickins <hugh@veritas.com>
In looking to do that, I made some other tidyups: can remove several
#includes, and sys_msync loop termination not quite right.
Most of those points are criticisms of the existing sys_msync, not of your
patch. In particular, the loop termination errors were introduced in 2.6.17:
I did notice this shortly before it came out, but decided I was more likely to
get it wrong myself, and make matters worse if I tried to rush a last-minute
fix in. And it's not terribly likely to go wrong, nor disastrous if it does
go wrong (may miss reporting an unmapped area; may also fsync file of a
following vma).
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Wrt. the recent modifications in do_wp_page() Hugh Dickins pointed out:
"I now realize it's right to the first order (normal case) and to the
second order (ptrace poke), but not to the third order (ptrace poke
anon page here to be COWed - perhaps can't occur without intervening
mprotects)."
This patch restores the old COW behaviour for anonymous pages.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Smallish cleanup to install_page(), could save a memory read (haven't checked
the asm output) and sure looks nicer.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
mprotect() resets the page protections, which could result in extra write
faults for those pages whose dirty state we track using write faults and are
dirty already.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Now that we can detect writers of shared mappings, throttle them. Avoids OOM
by surprise.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Tracking of dirty pages in shared writeable mmap()s.
The idea is simple: write protect clean shared writeable pages, catch the
write-fault, make writeable and set dirty. On page write-back clean all the
PTE dirty bits and write protect them once again.
The implementation is a tad harder, mainly because the default
backing_dev_info capabilities were too loosely maintained. Hence it is not
enough to test the backing_dev_info for cap_account_dirty.
The current heuristic is as follows, a VMA is eligible when:
- its shared writeable
(vm_flags & (VM_WRITE|VM_SHARED)) == (VM_WRITE|VM_SHARED)
- it is not a 'special' mapping
(vm_flags & (VM_PFNMAP|VM_INSERTPAGE)) == 0
- the backing_dev_info is cap_account_dirty
mapping_cap_account_dirty(vma->vm_file->f_mapping)
- f_op->mmap() didn't change the default page protection
Page from remap_pfn_range() are explicitly excluded because their COW
semantics are already horrid enough (see vm_normal_page() in do_wp_page()) and
because they don't have a backing store anyway.
mprotect() is taught about the new behaviour as well. However it overrides
the last condition.
Cleaning the pages on write-back is done with page_mkclean() a new rmap call.
It can be called on any page, but is currently only implemented for mapped
pages, if the page is found the be of a VMA that accounts dirty pages it will
also wrprotect the PTE.
Finally, in fs/buffers.c:try_to_free_buffers(); remove clear_page_dirty() from
under ->private_lock. This seems to be safe, since ->private_lock is used to
serialize access to the buffers, not the page itself. This is needed because
clear_page_dirty() will call into page_mkclean() and would thereby violate
locking order.
[dhowells@redhat.com: Provide a page_mkclean() implementation for NOMMU]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce a VM_BUG_ON, which is turned on with CONFIG_DEBUG_VM. Use this
in the lightweight, inline refcounting functions; PageLRU and PageActive
checks in vmscan, because they're pretty well confined to vmscan. And in
page allocate/free fastpaths which can be the hottest parts of the kernel
for kbuilds.
Unlike BUG_ON, VM_BUG_ON must not be used to execute statements with
side-effects, and should not be used outside core mm code.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Give non-highmem architectures access to the kmap API for the purposes of
overriding (this is what the attached patch does).
The proposal is that we should now require all architectures with coherence
issues to manage data coherence via the kmap/kunmap API. Thus driver
writers never have to write code like
kmap(page)
modify data in page
flush_kernel_dcache_page(page)
kunmap(page)
instead, kmap/kunmap will manage the coherence and driver (and filesystem)
writers don't need to worry about how to flush between kmap and kunmap.
For most architectures, the page only needs to be flushed if it was
actually written to *and* there are user mappings of it, so the best
implementation looks to be: clear the page dirty pte bit in the kernel page
tables on kmap and on kunmap, check page->mappings for user maps, and then
the dirty bit, and only flush if it both has user mappings and is dirty.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Original commit code assumes, that when a buffer on BJ_SyncData list is
locked, it is being written to disk. But this is not true and hence it can
lead to a potential data loss on crash. Also the code didn't count with
the fact that journal_dirty_data() can steal buffers from committing
transaction and hence could write buffers that no longer belong to the
committing transaction. Finally it could possibly happen that we tried
writing out one buffer several times.
The patch below tries to solve these problems by a complete rewrite of the
data commit code. We go through buffers on t_sync_datalist, lock buffers
needing write out and store them in an array. Buffers are also immediately
refiled to BJ_Locked list or unfiled (if the write out is completed). When
the array is full or we have to block on buffer lock, we submit all
accumulated buffers for IO.
[suitable for 2.6.18.x around the 2.6.19-rc2 timeframe]
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Christoph Lameter
Franck Bui-Huu
keith mannthey
Adrian Bunk
Peter Zijlstra
Nick Piggin
James Bottomley
Jan Kara