_PAGE_FILE does not indicate whether a file is in page / swap cache, it is
set just for non-linear PTE's.  Correct the comment for i386, x86_64, UML.
Also clearify _PAGE_NONE.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If !vma->vm-ops we already BUG above, so retesting it is useless.  The
compiler cannot optimize this because BUG is a macro and is not thus marked
noreturn; that should possibly be fixed.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Either shmem_getpage returns a failure, or it found a page, or it was told
it couldn't do any I/O.  So it's useless to check nonblock in the else
branch.  We could add a BUG() there but I preferred to comment the
offending function.

This was taken out from one Ingo Molnar's old patch I'm resurrecting.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix a small spelling mistake.  subtile->subtle
Signed-off-by: NMartin Hicks <mort@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

smp_entry_t -> swap_entry_t
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Better late than never, I've at last reviewed the madvise vma merging
going into 2.6.13.  Remove a pointless check and fix two little bugs -
a simple test (with /proc/<pid>/maps hacked to show ReadHints) showed
both mismerges in practice: though being madvise, neither was disastrous.

1. Correct placement of the success label in madvise_behavior: as in
   mprotect_fixup and mlock_fixup, it is necessary to update vm_flags
   when vma_merge succeeds (to handle the exceptional Case 8 noted in
   the comments above vma_merge itself).

2. Correct initial value of prev when starting part way into a vma: as
   in sys_mprotect and do_mlock, it needs to be set to vma in this case
   (vma_merge handles only that minimum of cases shown in its comments).

3. If find_vma_prev sets prev, then the vma it returns is prev->vm_next,
   so it's pointless to make that same assignment again in sys_madvise.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Christoph Lameter and Marcelo Tosatti asked to get rid of the
atomic_inc_and_test() to cleanup the atomic ops in the zone reclaim code.
Signed-off-by: NMartin Hicks <mort@sgi.com>
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add a capability check to sys_set_zone_reclaim().  This syscall is not
something that should be available to a user.
Signed-off-by: NMartin Hicks <mort@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This bitop does not need to be atomic because it is performed when there will
be no references to the page (ie.  the page is being freed).
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

filemap_xip's nopage routine maps the ZERO_PAGE into readonly mappings, if it
has no data page to map there: then if the hole in the file is later filled,
__xip_unmap uses an rmap technique to replace the ZERO_PAGEs mapped for that
offset by the newly allocated file page, so that established mappings will see
the newly written data.

However, on MIPS (alone) there's not one but as many as eight ZERO_PAGEs,
chosen for coloring by user virtual address; and if mremap has meanwhile been
used to move a mapping containing a ZERO_PAGE, it will generally not match the
ZERO_PAGE(address) __xip_unmap is looking for.

To maintain XIP's established mappings correctly on MIPS, we need Nick's fix
to mremap's move_one_page (originally presented as an optimization), to
replace the ZERO_PAGE appropriate to the old address by the ZERO_PAGE
appropriate to the new address.

(But when I first saw this, I was thinking the ZERO_PAGEs themselves would get
corrupted, very bad.  Now I think it's the other way round, that the
established mappings will fail to see the newly written data: incorrect, but
not corrupting everything else.  Whether filemap_xip's technique is generally
safe, I'd hesitate to say in a hurry: it's interesting, but we've never tried
to do that in tmpfs.)
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Thanks to Bill Irwin for pointing this out.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Microoptimise page_add_anon_rmap.  Although these expressions are used only in
the taken branch of the if() statement, the compiler can't reorder them inside
because atomic_inc_and_test is a barrier.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Just be clear that VM_RESERVED pages here are a bug, and the test is not there
because they are expected.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch was recently discussed on linux-mm:
http://marc.theaimsgroup.com/?t=112085728500002&r=1&w=2

I inherited a large code base from Ray for page migration.  There was a
small patch in there that I find to be very useful since it allows the
display of the locality of the pages in use by a process.  I reworked that
patch and came up with a /proc/<pid>/numa_maps that gives more information
about the vma's of a process.  numa_maps is indexes by the start address
found in /proc/<pid>/maps.  F.e.  with this patch you can see the page use
of the "getty" process:

margin:/proc/12008 # cat maps
00000000-00004000 r--p 00000000 00:00 0
2000000000000000-200000000002c000 r-xp 00000000 08:04 516                /lib/ld-2.3.3.so
2000000000038000-2000000000040000 rw-p 00028000 08:04 516                /lib/ld-2.3.3.so
2000000000040000-2000000000044000 rw-p 2000000000040000 00:00 0
2000000000058000-2000000000260000 r-xp 00000000 08:04 54707842           /lib/tls/libc.so.6.1
2000000000260000-2000000000268000 ---p 00208000 08:04 54707842           /lib/tls/libc.so.6.1
2000000000268000-2000000000274000 rw-p 00200000 08:04 54707842           /lib/tls/libc.so.6.1
2000000000274000-2000000000280000 rw-p 2000000000274000 00:00 0
2000000000280000-20000000002b4000 r--p 00000000 08:04 9126923            /usr/lib/locale/en_US.utf8/LC_CTYPE
2000000000300000-2000000000308000 r--s 00000000 08:04 60071467           /usr/lib/gconv/gconv-modules.cache
2000000000318000-2000000000328000 rw-p 2000000000318000 00:00 0
4000000000000000-4000000000008000 r-xp 00000000 08:04 29576399           /sbin/mingetty
6000000000004000-6000000000008000 rw-p 00004000 08:04 29576399           /sbin/mingetty
6000000000008000-600000000002c000 rw-p 6000000000008000 00:00 0          [heap]
60000fff7fffc000-60000fff80000000 rw-p 60000fff7fffc000 00:00 0
60000ffffff44000-60000ffffff98000 rw-p 60000ffffff44000 00:00 0          [stack]
a000000000000000-a000000000020000 ---p 00000000 00:00 0                  [vdso]

cat numa_maps
2000000000000000 default MaxRef=43 Pages=11 Mapped=11 N0=4 N1=3 N2=2 N3=2
2000000000038000 default MaxRef=1 Pages=2 Mapped=2 Anon=2 N0=2
2000000000040000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1
2000000000058000 default MaxRef=43 Pages=61 Mapped=61 N0=14 N1=15 N2=16 N3=16
2000000000268000 default MaxRef=1 Pages=2 Mapped=2 Anon=2 N0=2
2000000000274000 default MaxRef=1 Pages=3 Mapped=3 Anon=3 N0=3
2000000000280000 default MaxRef=8 Pages=3 Mapped=3 N0=3
2000000000300000 default MaxRef=8 Pages=2 Mapped=2 N0=2
2000000000318000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N2=1
4000000000000000 default MaxRef=6 Pages=2 Mapped=2 N1=2
6000000000004000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1
6000000000008000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1
60000fff7fffc000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1
60000ffffff44000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1

getty uses ld.so.  The first vma is the code segment which is used by 43
other processes and the pages are evenly distributed over the 4 nodes.

The second vma is the process specific data portion for ld.so.  This is
only one page.

The display format is:

<startaddress>	 Links to information in /proc/<pid>/map
<memory policy>  This can be "default" "interleave={}", "prefer=<node>" or "bind={<zones>}"
MaxRef=		<maximum reference to a page in this vma>
Pages=		<Nr of pages in use>
Mapped=		<Nr of pages with mapcount >
Anon=		<nr of anonymous pages>
Nx=		<Nr of pages on Node x>

The content of the proc-file is self-evident.  If this would be tied into
the sparsemem system then the contents of this file would not be too
useful.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove the three get_mm_counter(mm, rss) tests from rmap.c: there was a
time when testing rss was important to avoid a particular race between
dup_mmap and the anonmm rmap; but now it's just a rather silly pseudo-
optimization, made even more obscure by the get_mm_counter macro.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Three of the four BUG_ONs in delete_from_swap_cache are immediately
repeated in __delete_from_swap_cache: delete those and add the one.  But
perhaps mm/ is altogether overprovisioned with historic BUGs?
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Aha, swsusp dips into swap_info[], better update it to swap_lock.  It's
bitflipping flags with 0xFF, so get_swap_page will allocate from only the one
chosen device: let's change that to flip SWP_WRITEOK.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The idea of a swap_device_lock per device, and a swap_list_lock over them all,
is appealing; but in practice almost every holder of swap_device_lock must
already hold swap_list_lock, which defeats the purpose of the split.

The only exceptions have been swap_duplicate, valid_swaphandles and an
untrodden path in try_to_unuse (plus a few places added in this series).
valid_swaphandles doesn't show up high in profiles, but swap_duplicate does
demand attention.  However, with the hold time in get_swap_pages so much
reduced, I've not yet found a load and set of swap device priorities to show
even swap_duplicate benefitting from the split.  Certainly the split is mere
overhead in the common case of a single swap device.

So, replace swap_list_lock and swap_device_lock by spinlock_t swap_lock
(generally we seem to prefer an _ in the name, and not hide in a macro).

If someone can show a regression in swap_duplicate, then probably we should
add a hashlock for the swap_map entries alone (shorts being anatomic), so as
to help the case of the single swap device too.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The get_swap_page/scan_swap_map latency can be so bad that even those without
preemption configured deserve relief: periodically cond_resched.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

get_swap_page has often shown up on latency traces, doing lengthy scans while
holding two spinlocks.  swap_list_lock is already dropped, now scan_swap_map
drop swap_device_lock before scanning the swap_map.

While scanning for an empty cluster, don't worry that racing tasks may
allocate what was free and free what was allocated; but when allocating an
entry, check it's still free after retaking the lock.  Avoid dropping the lock
in the expected common path.  No barriers beyond the locks, just let the
cookie crumble; highest_bit limit is volatile, but benign.

Guard against swapoff: must check SWP_WRITEOK before allocating, must raise
SWP_SCANNING reference count while in scan_swap_map, swapoff wait for that to
fall - just use schedule_timeout, we don't want to burden scan_swap_map
itself, and it's very unlikely that anyone can really still be in
scan_swap_map once swapoff gets this far.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Rewrite scan_swap_map to allocate in just the same way as before (taking the
next free entry SWAPFILE_CLUSTER-1 times, then restarting at the lowest wholly
empty cluster, falling back to lowest entry if none), but with a view towards
dropping the lock in the next patch.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Rewrite get_swap_page to allocate in just the same sequence as before, but
without holding swap_list_lock across its scan_swap_map.  Decrement
nr_swap_pages and update swap_list.next in advance, while still holding
swap_list_lock.  Skip full devices by testing highest_bit.  Swapoff hold
swap_device_lock as well as swap_list_lock to clear SWP_WRITEOK.  Reduces lock
contention when there are parallel swap devices of the same priority.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This makes negligible difference in practice: but swap_list.next should not be
updated to a higher prio in the general helper swap_info_get, but rather in
swap_entry_free; and then only in the case when entry is actually freed.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The swap header's unsigned int last_page determines the range of swap pages,
but swap_info has been using int or unsigned long in some cases: use unsigned
int throughout (except, in several places a local unsigned long is useful to
avoid overflows when adding).
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The "Adding %dk swap" message shows the number of swap extents, as a guide to
how fragmented the swapfile may be.  But a useful further guide is what total
extent they span across (sometimes scarily large).

And there's no need to keep nr_extents in swap_info: it's unused after the
initial message, so save a little space by keeping it on stack.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There are several comments that swap's extent_list.prev points to the lowest
extent: that's not so, it's extent_list.next which points to it, as you'd
expect.  And a couple of loops in add_swap_extent which go all the way through
the list, when they should just add to the other end.

Fix those up, and let map_swap_page search the list forwards: profiles shows
it to be twice as quick that way - because prefetch works better on how the
structs are typically kmalloc'ed?  or because usually more is written to than
read from swap, and swap is allocated ascendingly?
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

sys_swapon's call to destroy_swap_extents on failure is made after the final
swap_list_unlock, which is faintly unsafe: another sys_swapon might already be
setting up that swap_info_struct.  Calling it earlier, before taking
swap_list_lock, is safe.  sys_swapoff's call to destroy_swap_extents was safe,
but likewise move it earlier, before taking the locks (once try_to_unuse has
completed, nothing can be needing the swap extents).
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If a regular swapfile lies on a filesystem whose blocksize is less than
PAGE_SIZE, then setup_swap_extents may have to cut the number of usable swap
pages; but sys_swapon's nr_good_pages was not expecting that.  Also,
setup_swap_extents takes no account of badpages listed in the swap header: not
worth doing so, but ensure nr_badpages is 0 for a regular swapfile.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update swap extents comment: nowadays we guard with S_SWAPFILE not i_sem.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Someone mentioned that almost all the architectures used basically the same
implementation of get_order.  This patch consolidates them into
asm-generic/page.h and includes that in the appropriate places.  The
exceptions are ia64 and ppc which have their own (presumably optimised)
versions.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This splits up sparse_index_alloc() into two pieces.  This is needed
because we'll allocate the memory for the second level in a different place
from where we actually consume it to keep the allocation from happening
underneath a lock
Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
Signed-off-by: NBob Picco <bob.picco@hp.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

With cleanups from Dave Hansen <haveblue@us.ibm.com>

SPARSEMEM_EXTREME makes mem_section a one dimensional array of pointers to
mem_sections.  This two level layout scheme is able to achieve smaller
memory requirements for SPARSEMEM with the tradeoff of an additional shift
and load when fetching the memory section.  The current SPARSEMEM
implementation is a one dimensional array of mem_sections which is the
default SPARSEMEM configuration.  The patch attempts isolates the
implementation details of the physical layout of the sparsemem section
array.

SPARSEMEM_EXTREME requires bootmem to be functioning at the time of
memory_present() calls.  This is not always feasible, so architectures
which do not need it may allocate everything statically by using
SPARSEMEM_STATIC.
Signed-off-by: NAndy Whitcroft <apw@shadowen.org>
Signed-off-by: NBob Picco <bob.picco@hp.com>
Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

A new option for SPARSEMEM is ARCH_SPARSEMEM_EXTREME.  Architecture
platforms with a very sparse physical address space would likely want to
select this option.  For those architecture platforms that don't select the
option, the code generated is equivalent to SPARSEMEM currently in -mm.
I'll be posting a patch on ia64 ml which uses this new SPARSEMEM feature.

ARCH_SPARSEMEM_EXTREME makes mem_section a one dimensional array of
pointers to mem_sections.  This two level layout scheme is able to achieve
smaller memory requirements for SPARSEMEM with the tradeoff of an
additional shift and load when fetching the memory section.  The current
SPARSEMEM -mm implementation is a one dimensional array of mem_sections
which is the default SPARSEMEM configuration.  The patch attempts isolates
the implementation details of the physical layout of the sparsemem section
array.

ARCH_SPARSEMEM_EXTREME depends on 64BIT and is by default boolean false.

I've boot tested under aim load ia64 configured for ARCH_SPARSEMEM_EXTREME.
 I've also boot tested a 4 way Opteron machine with !ARCH_SPARSEMEM_EXTREME
and tested with aim.
Signed-off-by: NAndy Whitcroft <apw@shadowen.org>
Signed-off-by: NBob Picco <bob.picco@hp.com>
Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Running 'make clean' was quietly deleting files in Mercurial kernel
repositories matching '.*.d', which was corrupting the tags portions of the
repository.  Spotted and fixed by several people.
Signed-off-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch corrects the PNP-handling inside the tpm-driver
and some minor coding style bugs.
Note: the pci-device and pnp-device mixture is currently necessary,
since the used "tpm"-interface requires a pci-dev in order to register
the driver. This will be fixed within the next iterations.
Signed-off-by: NMarcel Selhorst <selhorst@crypto.rub.de>
Cc: Kylene Hall <kjhall@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Please apply this to 2.6.14, and also to 2.6.13.1 -stable.  Without this
patch, users will have to EXPLICITLY select tda1004x in Kconfig.  This
SHOULD be done automatically when saa7134-dvb is selected.  This patch
corrects this problem.
Signed-off-by: NMichael Krufky <mkrufky@m1k.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Merge refs/heads/ieee80211-wifi from master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6 

This patch is against 2.6.10, but still applies cleanly. It's just
s/driverfs/sysfs/ in this file.
Signed-off-by: NRolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch is against 2.6.10, but still applies cleanly. It's just
s/driverfs/sysfs/ in these two files.
Signed-off-by: NRolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>