linux-stable.git/mm/page_alloc.c, branch v3.11.2

mm: honor min_free_kbytes set by user

2013-07-09T17:33:25+00:00

min_free_kbytes is updated during memory hotplug (by
init_per_zone_wmark_min) currently which is right thing to do in most
cases but this could be unexpected if admin increased the value to
prevent from allocation failures and the new min_free_kbytes would be
decreased as a result of memory hotadd.

This patch saves the user defined value and allows updating
min_free_kbytes only if it is higher than the saved one.

A warning is printed when the new value is ignored.

Signed-off-by: Michal Hocko 
Cc: Mel Gorman 
Acked-by: Zhang Yanfei 
Acked-by: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page_alloc.c: remove unlikely() from the current_order test

2013-07-09T17:33:22+00:00

In __rmqueue_fallback(), current_order loops down from MAX_ORDER - 1 to
the order passed.  MAX_ORDER is typically 11 and pageblock_order is
typically 9 on x86.  Integer division truncates, so pageblock_order / 2
is 4.  For the first eight iterations, it's guaranteed that
current_order >= pageblock_order / 2 if it even gets that far!

So just remove the unlikely(), it's completely bogus.

Signed-off-by: Zhang Yanfei 
Suggested-by: David Rientjes 
Acked-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page_alloc.c: remove zone_type argument of build_zonelists_node

2013-07-09T17:33:22+00:00

The callers of build_zonelists_node always pass MAX_NR_ZONES -1 as the
zone_type argument, so we can directly use the value in
build_zonelists_node and remove zone_type argument.

Signed-off-by: Zhang Yanfei 
Acked-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove duplicated call of get_pfn_range_for_nid

2013-07-09T17:33:20+00:00

When calculating pages in a node, for each zone in that node, we will
have

  zone_spanned_pages_in_node
    --> get_pfn_range_for_nid
  zone_absent_pages_in_node
    --> get_pfn_range_for_nid

That is to say, we call the get_pfn_range_for_nid to get start_pfn and
end_pfn of the node for MAX_NR_ZONES * 2 times.  And this is totally
unnecessary if we call the get_pfn_range_for_nid before
zone_*_pages_in_node add two extra arguments node_start_pfn and
node_end_pfn for zone_*_pages_in_node, then we can remove the
get_pfn_range_in_node in zone_*_pages_in_node.

[akpm@linux-foundation.org: make definitions more readable]
Signed-off-by: Zhang Yanfei 
Cc: Michal Hocko 
Cc: Wu Fengguang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: introduce helper function mem_init_print_info() to simplify mem_init()

2013-07-03T23:07:35+00:00

Introduce helper function mem_init_print_info() to simplify mem_init()
across different architectures, which also unifies the format and
information printed.

Function mem_init_print_info() calculates memory statistics information
without walking each page, so it should be a little faster on some
architectures.

Also introduce another helper get_num_physpages() to kill the global
variable num_physpages.

Signed-off-by: Jiang Liu 
Cc: Mel Gorman 
Cc: Michel Lespinasse 
Cc: Rik van Riel 
Cc: Minchan Kim 
Cc: Marek Szyprowski 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: report available pages as "MemTotal" for each NUMA node

2013-07-03T23:07:34+00:00

As reported by https://bugzilla.kernel.org/show_bug.cgi?id=53501,
"MemTotal" from /proc/meminfo means memory pages managed by the buddy
system (managed_pages), but "MemTotal" from /sys/.../node/nodex/meminfo
means physical pages present (present_pages) within the NUMA node.
There's a difference between managed_pages and present_pages due to
bootmem allocator and reserved pages.

And Documentation/filesystems/proc.txt says
    MemTotal: Total usable ram (i.e. physical ram minus a few reserved
              bits and the kernel binary code)

So change /sys/.../node/nodex/meminfo to report available pages within
the node as "MemTotal".

Signed-off-by: Jiang Liu 
Reported-by: 
Cc: Mel Gorman 
Cc: Minchan Kim 
Cc: "H. Peter Anvin" 
Cc: "Michael S. Tsirkin" 
Cc: Arnd Bergmann 
Cc: Catalin Marinas 
Cc: Chris Metcalf 
Cc: David Howells 
Cc: Geert Uytterhoeven 
Cc: Ingo Molnar 
Cc: Jeremy Fitzhardinge 
Cc: Jianguo Wu 
Cc: Joonsoo Kim 
Cc: Kamezawa Hiroyuki 
Cc: Konrad Rzeszutek Wilk 
Cc: Marek Szyprowski 
Cc: Michel Lespinasse 
Cc: Rik van Riel 
Cc: Rusty Russell 
Cc: Tang Chen 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Cc: Wen Congyang 
Cc: Will Deacon 
Cc: Yasuaki Ishimatsu 
Cc: Yinghai Lu 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: correctly update zone->managed_pages

2013-07-03T23:07:33+00:00

Enhance adjust_managed_page_count() to adjust totalhigh_pages for
highmem pages.  And change code which directly adjusts totalram_pages to
use adjust_managed_page_count() because it adjusts totalram_pages,
totalhigh_pages and zone->managed_pages altogether in a safe way.

Remove inc_totalhigh_pages() and dec_totalhigh_pages() from xen/balloon
driver bacause adjust_managed_page_count() has already adjusted
totalhigh_pages.

This patch also fixes two bugs:

1) enhances virtio_balloon driver to adjust totalhigh_pages when
   reserve/unreserve pages.
2) enhance memory_hotplug.c to adjust totalhigh_pages when hot-removing
   memory.

We still need to deal with modifications of totalram_pages in file
arch/powerpc/platforms/pseries/cmm.c, but need help from PPC experts.

[akpm@linux-foundation.org: remove ifdef, per Wanpeng Li, virtio_balloon.c cleanup, per Sergei]
[akpm@linux-foundation.org: export adjust_managed_page_count() to modules, for drivers/virtio/virtio_balloon.c]
Signed-off-by: Jiang Liu 
Cc: Chris Metcalf 
Cc: Rusty Russell 
Cc: "Michael S. Tsirkin" 
Cc: Konrad Rzeszutek Wilk 
Cc: Jeremy Fitzhardinge 
Cc: Wen Congyang 
Cc: Tang Chen 
Cc: Yasuaki Ishimatsu 
Cc: Mel Gorman 
Cc: Minchan Kim 
Cc: "H. Peter Anvin" 
Cc: 
Cc: Arnd Bergmann 
Cc: Catalin Marinas 
Cc: David Howells 
Cc: Geert Uytterhoeven 
Cc: Ingo Molnar 
Cc: Jianguo Wu 
Cc: Joonsoo Kim 
Cc: Kamezawa Hiroyuki 
Cc: Marek Szyprowski 
Cc: Michel Lespinasse 
Cc: Rik van Riel 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: Yinghai Lu 
Cc: Russell King 
Cc: Sergei Shtylyov 
Cc: Wu Fengguang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: make __free_pages_bootmem() only available at boot time

2013-07-03T23:07:33+00:00

In order to simpilify management of totalram_pages and
zone->managed_pages, make __free_pages_bootmem() only available at boot
time.  With this change applied, __free_pages_bootmem() will only be
used by bootmem.c and nobootmem.c at boot time, so mark it as __init.
Other callers of __free_pages_bootmem() have been converted to use
free_reserved_page(), which handles totalram_pages and
zone->managed_pages in a safer way.

This patch also fix a bug in free_pagetable() for x86_64, which should
increase zone->managed_pages instead of zone->present_pages when freeing
reserved pages.

And now we have managed_pages_count_lock to protect totalram_pages and
zone->managed_pages, so remove the redundant ppb_lock lock in
put_page_bootmem().  This greatly simplifies the locking rules.

Signed-off-by: Jiang Liu 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Yinghai Lu 
Cc: Wen Congyang 
Cc: Tang Chen 
Cc: Yasuaki Ishimatsu 
Cc: Mel Gorman 
Cc: Minchan Kim 
Cc: "Michael S. Tsirkin" 
Cc: 
Cc: Arnd Bergmann 
Cc: Catalin Marinas 
Cc: Chris Metcalf 
Cc: David Howells 
Cc: Geert Uytterhoeven 
Cc: Jeremy Fitzhardinge 
Cc: Jianguo Wu 
Cc: Joonsoo Kim 
Cc: Kamezawa Hiroyuki 
Cc: Konrad Rzeszutek Wilk 
Cc: Marek Szyprowski 
Cc: Michel Lespinasse 
Cc: Rik van Riel 
Cc: Rusty Russell 
Cc: Tejun Heo 
Cc: Will Deacon 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: use a dedicated lock to protect totalram_pages and zone->managed_pages

2013-07-03T23:07:33+00:00

Currently lock_memory_hotplug()/unlock_memory_hotplug() are used to
protect totalram_pages and zone->managed_pages.  Other than the memory
hotplug driver, totalram_pages and zone->managed_pages may also be
modified at runtime by other drivers, such as Xen balloon,
virtio_balloon etc.  For those cases, memory hotplug lock is a little
too heavy, so introduce a dedicated lock to protect totalram_pages and
zone->managed_pages.

Now we have a simplified locking rules totalram_pages and
zone->managed_pages as:

1) no locking for read accesses because they are unsigned long.
2) no locking for write accesses at boot time in single-threaded context.
3) serialize write accesses at runtime by acquiring the dedicated
   managed_page_count_lock.

Also adjust zone->managed_pages when freeing reserved pages into the
buddy system, to keep totalram_pages and zone->managed_pages in
consistence.

[akpm@linux-foundation.org: don't export adjust_managed_page_count to modules (for now)]
Signed-off-by: Jiang Liu 
Cc: Mel Gorman 
Cc: Michel Lespinasse 
Cc: Rik van Riel 
Cc: Minchan Kim 
Cc: "H. Peter Anvin" 
Cc: "Michael S. Tsirkin" 
Cc: 
Cc: Arnd Bergmann 
Cc: Catalin Marinas 
Cc: Chris Metcalf 
Cc: David Howells 
Cc: Geert Uytterhoeven 
Cc: Ingo Molnar 
Cc: Jeremy Fitzhardinge 
Cc: Jianguo Wu 
Cc: Joonsoo Kim 
Cc: Kamezawa Hiroyuki 
Cc: Konrad Rzeszutek Wilk 
Cc: Marek Szyprowski 
Cc: Rusty Russell 
Cc: Tang Chen 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Cc: Wen Congyang 
Cc: Will Deacon 
Cc: Yasuaki Ishimatsu 
Cc: Yinghai Lu 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: accurately calculate zone->managed_pages for highmem zones

2013-07-03T23:07:33+00:00

Commit "mm: introduce new field 'managed_pages' to struct zone" assumes
that all highmem pages will be freed into the buddy system by function
mem_init().  But that's not always true, some architectures may reserve
some highmem pages during boot.  For example PPC may allocate highmem
pages for giagant HugeTLB pages, and several architectures have code to
check PageReserved flag to exclude highmem pages allocated during boot
when freeing highmem pages into the buddy system.

So treat highmem pages in the same way as normal pages, that is to:
1) reset zone->managed_pages to zero in mem_init().
2) recalculate managed_pages when freeing pages into the buddy system.

Signed-off-by: Jiang Liu 
Cc: "H. Peter Anvin" 
Cc: Tejun Heo 
Cc: Joonsoo Kim 
Cc: Yinghai Lu 
Cc: Mel Gorman 
Cc: Minchan Kim 
Cc: Kamezawa Hiroyuki 
Cc: Marek Szyprowski 
Cc: "Michael S. Tsirkin" 
Cc: 
Cc: Arnd Bergmann 
Cc: Catalin Marinas 
Cc: Chris Metcalf 
Cc: David Howells 
Cc: Geert Uytterhoeven 
Cc: Ingo Molnar 
Cc: Jeremy Fitzhardinge 
Cc: Jianguo Wu 
Cc: Konrad Rzeszutek Wilk 
Cc: Michel Lespinasse 
Cc: Rik van Riel 
Cc: Rusty Russell 
Cc: Tang Chen 
Cc: Thomas Gleixner 
Cc: Wen Congyang 
Cc: Will Deacon 
Cc: Yasuaki Ishimatsu 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds