linux-stable.git/mm/page_alloc.c, branch linux-2.6.24.y

mm: fix section mismatch warning in page_alloc.c

2008-01-17T23:38:58+00:00

With CONFIG_HOTPLUG=n and CONFIG_HOTPLUG_CPU=y we saw
following warning:
WARNING: mm/built-in.o(.text+0x6864): Section mismatch: reference to .init.text: (between 'process_zones' and 'pageset_cpuup_callback')

The culprit was zone_batchsize() which were annotated __devinit but used
from process_zones() which is annotated __cpuinit.  zone_batchsize() are
used from another function annotated __meminit so the only valid option is
to drop the annotation of zone_batchsize() so we know it is always valid to
use it.

Signed-off-by: Sam Ravnborg 
Acked-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix crash with FLAT_MEMORY and ARCH_PFN_OFFSET != 0

2008-01-09T00:10:36+00:00

When using FLAT_MEMORY and ARCH_PFN_OFFSET is not 0, the kernel crashes in
memmap_init_zone().  This bug got introduced by commit
c713216deebd95d2b0ab38fef8bb2361c0180c2d

Signed-off-by: Thomas Bogendoerfer 
Acked-by: Mel Gorman 
Cc: Bob Picco 
Cc: Dave Hansen 
Cc: Andy Whitcroft 
Cc: Andi Kleen 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "Keith Mannthey" 
Cc: "Luck, Tony" 
Cc: KAMEZAWA Hiroyuki 
Cc: Yasunori Goto 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: fix page allocation for larger I/O segments

2007-12-18T03:28:16+00:00

In some cases the IO subsystem is able to merge requests if the pages are
adjacent in physical memory.  This was achieved in the allocator by having
expand() return pages in physically contiguous order in situations were a
large buddy was split.  However, list-based anti-fragmentation changed the
order pages were returned in to avoid searching in buffered_rmqueue() for a
page of the appropriate migrate type.

This patch restores behaviour of rmqueue_bulk() preserving the physical
order of pages returned by the allocator without incurring increased search
costs for anti-fragmentation.

Signed-off-by: Mel Gorman 
Cc: James Bottomley 
Cc: Jens Axboe 
Cc: Mark Lord 
Signed-off-by: Linus Torvalds

Fix boot problem with iSeries lacking hugepage support

2007-11-29T17:24:51+00:00

Ordinarily the size of a pageblock is determined at compile-time based on the
hugepage size. On PPC64, the hugepage size is determined at runtime based on
what is supported by the machine. With legacy machines such as iSeries that
do not support hugepages, HPAGE_SHIFT is 0. This results in pageblock_order
being set to -PAGE_SHIFT and a crash results shortly afterwards.

This patch adds a function to select a sensible value for pageblock order by
default when HUGETLB_PAGE_SIZE_VARIABLE is set. It checks that HPAGE_SHIFT
is a sensible value before using the hugepage size; if it is not MAX_ORDER-1
is used.

This is a fix for 2.6.24.

Credit goes to Stephen Rothwell for identifying the bug and testing candidate
patches.  Additional credit goes to Andy Whitcroft for spotting a problem
with respects to IA-64 before releasing. Additional credit to David Gibson
for testing with the libhugetlbfs test suite.

Signed-off-by: Mel Gorman 
Tested-by: Stephen Rothwell 
Cc: Benjamin Herrenschmidt 
Acked-by: Paul Mackerras 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

prep_zero_page: remove bogus BUG_ON

2007-11-28T19:04:28+00:00

2.6.11 gave __GFP_ZERO's prep_zero_page a bogus "highmem may have to wait"
assertion.  Presumably added under the misconception that clear_highpage
uses nonatomic kmap; but then and now it uses kmap_atomic, so no problem.

Signed-off-by: Hugh Dickins 
Signed-off-by: Linus Torvalds

Revert "Bias the placement of kernel pages at lower PFNs"

2007-11-12T22:14:44+00:00

This reverts commit 5adc5be7cd1bcef6bb64f5255d2a33f20a3cf5be.

Alexey Dobriyan reports that it causes huge slowdowns under some loads,
in his case a "mkfs.ext2" on a 30G partition.  With the placement bias,
the mkfs took over four minutes, with it reverted it's back to about ten
seconds for Alexey.

Reported-and-tested-by: Alexey Dobriyan 
Cc: Mel Gorman 
Cc: Andrew Morton 
Signed-off-by: Linus Torvalds

spelling fixes: mm/

2007-10-19T23:27:18+00:00

Spelling fixes in mm/.

Signed-off-by: Simon Arlott 
Signed-off-by: Adrian Bunk

oom: serialize out of memory calls

2007-10-17T15:42:45+00:00

A final allocation attempt with a very high watermark needs to be attempted
before invoking out_of_memory().  OOM killer serialization needs to occur
before this final attempt, otherwise tasks attempting to OOM-lock all zones in
its zonelist may spin and acquire the lock unnecessarily after the OOM
condition has already been alleviated.

If the final allocation does succeed, the zonelist is simply OOM-unlocked and
__alloc_pages() returns the page.  Otherwise, the OOM killer is invoked.

If the task cannot acquire OOM-locks on all zones in its zonelist, it is put
to sleep and the allocation is retried when it gets rescheduled.  One of its
zones is already marked as being in the OOM killer so it'll hopefully be
getting some free memory soon, at least enough to satisfy a high watermark
allocation attempt.  This prevents needlessly killing a task when the OOM
condition would have already been alleviated if it had simply been given
enough time.

Cc: Andrea Arcangeli 
Acked-by: Christoph Lameter 
Signed-off-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

oom: change all_unreclaimable zone member to flags

2007-10-17T15:42:45+00:00

Convert the int all_unreclaimable member of struct zone to unsigned long
flags.  This can now be used to specify several different zone flags such as
all_unreclaimable and reclaim_in_progress, which can now be removed and
converted to a per-zone flag.

Flags are set and cleared as follows:

	zone_set_flag(struct zone *zone, zone_flags_t flag)
	zone_clear_flag(struct zone *zone, zone_flags_t flag)

Defines the first zone flags, ZONE_ALL_UNRECLAIMABLE and ZONE_RECLAIM_LOCKED,
which have the same semantics as the old zone->all_unreclaimable and
zone->reclaim_in_progress, respectively.  Also converts all current users that
set or clear either flag to use the new interface.

Helper functions are defined to test the flags:

	int zone_is_all_unreclaimable(const struct zone *zone)
	int zone_is_reclaim_locked(const struct zone *zone)

All flag operators are of the atomic variety because there are currently
readers that are implemented that do not take zone->lock.

[akpm@linux-foundation.org: add needed include]
Cc: Andrea Arcangeli 
Acked-by: Christoph Lameter 
Signed-off-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

oom: move prototypes to appropriate header file

2007-10-17T15:42:45+00:00

Move the OOM killer's extern function prototypes to include/linux/oom.h and
include it where necessary.

[clg@fr.ibm.com: build fix]
Cc: Andrea Arcangeli 
Acked-by: Christoph Lameter 
Signed-off-by: David Rientjes 
Signed-off-by: Cedric Le Goater 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds