linux-stable.git/mm/page_alloc.c, branch linux-3.9.y

mm/memory-hotplug: fix lowmem count overflow when offline pages

2013-07-21T00:16:09+00:00

commit cea27eb2a202959783f81254c48c250ddd80e129 upstream.

The logic for the memory-remove code fails to correctly account the
Total High Memory when a memory block which contains High Memory is
offlined as shown in the example below.  The following patch fixes it.

Before logic memory remove:

MemTotal:        7603740 kB
MemFree:         6329612 kB
Buffers:           94352 kB
Cached:           872008 kB
SwapCached:            0 kB
Active:           626932 kB
Inactive:         519216 kB
Active(anon):     180776 kB
Inactive(anon):   222944 kB
Active(file):     446156 kB
Inactive(file):   296272 kB
Unevictable:           0 kB
Mlocked:               0 kB
HighTotal:       7294672 kB
HighFree:        5704696 kB
LowTotal:         309068 kB
LowFree:          624916 kB

After logic memory remove:

MemTotal:        7079452 kB
MemFree:         5805976 kB
Buffers:           94372 kB
Cached:           872000 kB
SwapCached:            0 kB
Active:           626936 kB
Inactive:         519236 kB
Active(anon):     180780 kB
Inactive(anon):   222944 kB
Active(file):     446156 kB
Inactive(file):   296292 kB
Unevictable:           0 kB
Mlocked:               0 kB
HighTotal:       7294672 kB
HighFree:        5181024 kB
LowTotal:       4294752076 kB
LowFree:          624952 kB

[mhocko@suse.cz: fix CONFIG_HIGHMEM=n build]
Signed-off-by: Wanpeng Li 
Reviewed-by: Michal Hocko 
Cc: KAMEZAWA Hiroyuki 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm/page_alloc.c: fix watermark check in __zone_watermark_ok()

2013-06-20T19:01:31+00:00

commit 026b08147923142e925a7d0aaa39038055ae0156 upstream.

The watermark check consists of two sub-checks.  The first one is:

	if (free_pages <= min + lowmem_reserve)
		return false;

The check assures that there is minimal amount of RAM in the zone.  If
CMA is used then the free_pages is reduced by the number of free pages
in CMA prior to the over-mentioned check.

	if (!(alloc_flags & ALLOC_CMA))
		free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);

This prevents the zone from being drained from pages available for
non-movable allocations.

The second check prevents the zone from getting too fragmented.

	for (o = 0; o < order; o++) {
		free_pages -= z->free_area[o].nr_free << o;
		min >>= 1;
		if (free_pages <= min)
			return false;
	}

The field z->free_area[o].nr_free is equal to the number of free pages
including free CMA pages.  Therefore the CMA pages are subtracted twice.
This may cause a false positive fail of __zone_watermark_ok() if the CMA
area gets strongly fragmented.  In such a case there are many 0-order
free pages located in CMA.  Those pages are subtracted twice therefore
they will quickly drain free_pages during the check against
fragmentation.  The test fails even though there are many free non-cma
pages in the zone.

This patch fixes this issue by subtracting CMA pages only for a purpose of
(free_pages <= min + lowmem_reserve) check.

Laura said:

  We were observing allocation failures of higher order pages (order 5 =
  128K typically) under tight memory conditions resulting in driver
  failure.  The output from the page allocation failure showed plenty of
  free pages of the appropriate order/type/zone and mostly CMA pages in
  the lower orders.

  For full disclosure, we still observed some page allocation failures
  even after applying the patch but the number was drastically reduced and
  those failures were attributed to fragmentation/other system issues.

Signed-off-by: Tomasz Stanislawski 
Signed-off-by: Kyungmin Park 
Tested-by: Laura Abbott 
Cc: Bartlomiej Zolnierkiewicz 
Acked-by: Minchan Kim 
Cc: Mel Gorman 
Tested-by: Marek Szyprowski 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

x86, ACPI, mm: Revert movablemem_map support

2013-03-02T17:34:39+00:00

Tim found:

  WARNING: at arch/x86/kernel/smpboot.c:324 topology_sane.isra.2+0x6f/0x80()
  Hardware name: S2600CP
  sched: CPU #1's llc-sibling CPU #0 is not on the same node! [node: 1 != 0]. Ignoring dependency.
  smpboot: Booting Node   1, Processors  #1
  Modules linked in:
  Pid: 0, comm: swapper/1 Not tainted 3.9.0-0-generic #1
  Call Trace:
    set_cpu_sibling_map+0x279/0x449
    start_secondary+0x11d/0x1e5

Don Morris reproduced on a HP z620 workstation, and bisected it to
commit e8d195525809 ("acpi, memory-hotplug: parse SRAT before memblock
is ready")

It turns out movable_map has some problems, and it breaks several things

1. numa_init is called several times, NOT just for srat. so those
	nodes_clear(numa_nodes_parsed)
	memset(&numa_meminfo, 0, sizeof(numa_meminfo))
   can not be just removed.  Need to consider sequence is: numaq, srat, amd, dummy.
   and make fall back path working.

2. simply split acpi_numa_init to early_parse_srat.
   a. that early_parse_srat is NOT called for ia64, so you break ia64.
   b.  for (i = 0; i < MAX_LOCAL_APIC; i++)
	     set_apicid_to_node(i, NUMA_NO_NODE)
     still left in numa_init. So it will just clear result from early_parse_srat.
     it should be moved before that....
   c.  it breaks ACPI_TABLE_OVERIDE...as the acpi table scan is moved
       early before override from INITRD is settled.

3. that patch TITLE is total misleading, there is NO x86 in the title,
   but it changes critical x86 code. It caused x86 guys did not
   pay attention to find the problem early. Those patches really should
   be routed via tip/x86/mm.

4. after that commit, following range can not use movable ram:
  a. real_mode code.... well..funny, legacy Node0 [0,1M) could be hot-removed?
  b. initrd... it will be freed after booting, so it could be on movable...
  c. crashkernel for kdump...: looks like we can not put kdump kernel above 4G
	anymore.
  d. init_mem_mapping: can not put page table high anymore.
  e. initmem_init: vmemmap can not be high local node anymore. That is
     not good.

If node is hotplugable, the mem related range like page table and
vmemmap could be on the that node without problem and should be on that
node.

We have workaround patch that could fix some problems, but some can not
be fixed.

So just remove that offending commit and related ones including:

 f7210e6c4ac7 ("mm/memblock.c: use CONFIG_HAVE_MEMBLOCK_NODE_MAP to
    protect movablecore_map in memblock_overlaps_region().")

 01a178a94e8e ("acpi, memory-hotplug: support getting hotplug info from
    SRAT")

 27168d38fa20 ("acpi, memory-hotplug: extend movablemem_map ranges to
    the end of node")

 e8d195525809 ("acpi, memory-hotplug: parse SRAT before memblock is
    ready")

 fb06bc8e5f42 ("page_alloc: bootmem limit with movablecore_map")

 42f47e27e761 ("page_alloc: make movablemem_map have higher priority")

 6981ec31146c ("page_alloc: introduce zone_movable_limit[] to keep
    movable limit for nodes")

 34b71f1e04fc ("page_alloc: add movable_memmap kernel parameter")

 4d59a75125d5 ("x86: get pg_data_t's memory from other node")

Later we should have patches that will make sure kernel put page table
and vmemmap on local node ram instead of push them down to node0.  Also
need to find way to put other kernel used ram to local node ram.

Reported-by: Tim Gardner 
Reported-by: Don Morris 
Bisected-by: Don Morris 
Tested-by: Don Morris 
Signed-off-by: Yinghai Lu 
Cc: Tony Luck 
Cc: Thomas Renninger 
Cc: Tejun Heo 
Cc: Tang Chen 
Cc: Yasuaki Ishimatsu 
Signed-off-by: Linus Torvalds

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2013-02-25T23:41:43+00:00

Pull module update from Rusty Russell:
 "The sweeping change is to make add_taint() explicitly indicate whether
  to disable lockdep, but it's a mechanical change."

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  MODSIGN: Add option to not sign modules during modules_install
  MODSIGN: Add -s  option to sign-file
  MODSIGN: Specify the hash algorithm on sign-file command line
  MODSIGN: Simplify Makefile with a Kconfig helper
  module: clean up load_module a little more.
  modpost: Ignore ARC specific non-alloc sections
  module: constify within_module_*
  taint: add explicit flag to show whether lock dep is still OK.
  module: printk message when module signature fail taints kernel.

mm: accurately document nr_free_*_pages functions with code comments

2013-02-24T01:50:22+00:00

nr_free_zone_pages(), nr_free_buffer_pages() and nr_free_pagecache_pages()
are horribly badly named, so accurately document them with code comments
in case of the misuse of them.

[akpm@linux-foundation.org: tweak comments]
Reviewed-by: Randy Dunlap 
Signed-off-by: Zhang Yanfei 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: fix return type for functions nr_free_*_pages

2013-02-24T01:50:21+00:00

Currently, the amount of RAM that functions nr_free_*_pages return is
held in unsigned int.  But in machines with big memory (exceeding 16TB),
the amount may be incorrect because of overflow, so fix it.

Signed-off-by: Zhang Yanfei 
Cc: Simon Horman 
Cc: Julian Anastasov 
Cc: David Miller 
Cc: Eric Van Hensbergen 
Cc: Ron Minnich 
Cc: Latchesar Ionkov 
Cc: Mel Gorman 
Cc: Minchan Kim 
Cc: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: use NUMA_NO_NODE

2013-02-24T01:50:21+00:00

Make a sweep through mm/ and convert code that uses -1 directly to using
the more appropriate NUMA_NO_NODE.

Signed-off-by: David Rientjes 
Reviewed-by: Yasuaki Ishimatsu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page_alloc: add informative debugging message in page_outside_zone_boundaries()

2013-02-24T01:50:20+00:00

Add a debug message which prints when a page is found outside of the
boundaries of the zone it should belong to. Format is:
	"page $pfn outside zone [ $start_pfn - $end_pfn ]"

[akpm@linux-foundation.org: s/pr_debug/pr_err/]
Signed-off-by: Cody P Schafer 
Cc: David Hansen 
Cc: Catalin Marinas 
Cc: Johannes Weiner 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page_alloc: add a VM_BUG in __free_one_page() if the zone is uninitialized.

2013-02-24T01:50:20+00:00

Freeing pages to uninitialized zones is not handled by
__free_one_page(), and should never happen when the code is correct.

Ran into this while writing some code that dynamically onlines extra
zones.

Signed-off-by: Cody P Schafer 
Cc: David Hansen 
Cc: Catalin Marinas 
Cc: Johannes Weiner 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: add & use zone_end_pfn() and zone_spans_pfn()

2013-02-24T01:50:20+00:00

Add 2 helpers (zone_end_pfn() and zone_spans_pfn()) to reduce code
duplication.

This also switches to using them in compaction (where an additional
variable needed to be renamed), page_alloc, vmstat, memory_hotplug, and
kmemleak.

Note that in compaction.c I avoid calling zone_end_pfn() repeatedly
because I expect at some point the sycronization issues with start_pfn &
spanned_pages will need fixing, either by actually using the seqlock or
clever memory barrier usage.

Signed-off-by: Cody P Schafer 
Cc: David Hansen 
Cc: Catalin Marinas 
Cc: Johannes Weiner 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds