GitLab

[ Upstream commit ddffe98d ]

To identify that pages of page table are allocated from bootmem
allocator, magic number sets to page->lru.next.

But page->lru list is initialized in reserve_bootmem_region().  So when
calling free_pagetable(), the function cannot find the magic number of
pages.  And free_pagetable() frees the pages by free_reserved_page() not
put_page_bootmem().

But if the pages are allocated from bootmem allocator and used as page
table, the pages have private flag.  So before freeing the pages, we
should clear the private flag by put_page_bootmem().

Before applying the commit 7bfec6f4 ("mm, page_alloc: check multiple
page fields with a single branch"), we could find the following visible
issue:

  BUG: Bad page state in process kworker/u1024:1
  page:ffffea103cfd8040 count:0 mapcount:0 mappi
  flags: 0x6fffff80000800(private)
  page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
  bad because of flags: 0x800(private)
  <snip>
  Call Trace:
  [...] dump_stack+0x63/0x87
  [...] bad_page+0x114/0x130
  [...] free_pages_prepare+0x299/0x2d0
  [...] free_hot_cold_page+0x31/0x150
  [...] __free_pages+0x25/0x30
  [...] free_pagetable+0x6f/0xb4
  [...] remove_pagetable+0x379/0x7ff
  [...] vmemmap_free+0x10/0x20
  [...] sparse_remove_one_section+0x149/0x180
  [...] __remove_pages+0x2e9/0x4f0
  [...] arch_remove_memory+0x63/0xc0
  [...] remove_memory+0x8c/0xc0
  [...] acpi_memory_device_remove+0x79/0xa5
  [...] acpi_bus_trim+0x5a/0x8d
  [...] acpi_bus_trim+0x38/0x8d
  [...] acpi_device_hotplug+0x1b7/0x418
  [...] acpi_hotplug_work_fn+0x1e/0x29
  [...] process_one_work+0x152/0x400
  [...] worker_thread+0x125/0x4b0
  [...] kthread+0xd8/0xf0
  [...] ret_from_fork+0x22/0x40

And the issue still silently occurs.

Until freeing the pages of page table allocated from bootmem allocator,
the page->freelist is never used.  So the patch sets magic number to
page->freelist instead of page->lru.next.

[isimatu.yasuaki@jp.fujitsu.com: fix merge issue]
  Link: http://lkml.kernel.org/r/722b1cc4-93ac-dd8b-2be2-7a7e313b3b0b@gmail.com
Link: http://lkml.kernel.org/r/2c29bd9f-5b67-02d0-18a3-8828e78bbb6f@gmail.com

Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

There was only one use of __initdata_refok and __exit_refok

__init_refok was used 46 times against 82 for __ref.

Those definitions are obsolete since commit 312b1485 ("Introduce new
section reference annotations tags: __ref, __refdata, __refconst")

This patch removes the following compatibility definitions and replaces
them treewide.

/* compatibility defines */
#define __init_refok     __ref
#define __initdata_refok __refdata
#define __exit_refok     __ref

I can also provide separate patches if necessary.
(One patch per tree and check in 1 month or 2 to remove old definitions)

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1466796271-3043-1-git-send-email-fabf@skynet.be

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When CONFIG_SPARSEMEM_EXTREME is disabled, __section_nr can get the
section number with a subtraction directly.

Link: http://lkml.kernel.org/r/1468988310-11560-1-git-send-email-zhouchengming1@huawei.com

Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Li Bin <huawei.libin@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Most of the mm subsystem uses pr_<level> so make it consistent.

Miscellanea:

 - Realign arguments
 - Add missing newline to format
 - kmemleak-test.c has a "kmemleak: " prefix added to the
   "Kmemleak testing" logging message via pr_fmt
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Tejun Heo <tj@kernel.org>	[percpu]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Kernel style prefers a single string over split strings when the string is
'user-visible'.

Miscellanea:

 - Add a missing newline
 - Realign arguments
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Tejun Heo <tj@kernel.org>	[percpu]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In support of providing struct page for large persistent memory
capacities, use struct vmem_altmap to change the default policy for
allocating memory for the memmap array.  The default vmemmap_populate()
allocates page table storage area from the page allocator.  Given
persistent memory capacities relative to DRAM it may not be feasible to
store the memmap in 'System Memory'.  Instead vmem_altmap represents
pre-allocated "device pages" to satisfy vmemmap_alloc_block_buf()
requests.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: kbuild test robot <lkp@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

To increase compiler portability there is <linux/compiler.h> which
provides convenience macros for various gcc constructs.  Eg: __weak for
__attribute__((weak)).  I've replaced all instances of gcc attributes with
the right macro in the memory management (/mm) subsystem.

[akpm@linux-foundation.org: while-we're-there consistency tweaks]
Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

retmain -> remain
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Switch to memblock interfaces for early memory allocator instead of
bootmem allocator.  No functional change in beahvior than what it is in
current code from bootmem users points of view.

Archs already converted to NO_BOOTMEM now directly use memblock
interfaces instead of bootmem wrappers build on top of memblock.  And
the archs which still uses bootmem, these new apis just fallback to
exiting bootmem APIs.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We pass the number of pages which hold page structs of a memory section
to free_map_bootmem().  This is right when !CONFIG_SPARSEMEM_VMEMMAP but
wrong when CONFIG_SPARSEMEM_VMEMMAP.  When CONFIG_SPARSEMEM_VMEMMAP, we
should pass the number of pages of a memory section to free_map_bootmem.

So the fix is removing the nr_pages parameter.  When
CONFIG_SPARSEMEM_VMEMMAP, we directly use the prefined marco
PAGES_PER_SECTION in free_map_bootmem.  When !CONFIG_SPARSEMEM_VMEMMAP,
we calculate page numbers needed to hold the page structs for a memory
section and use the value in free_map_bootmem().

This was found by reading the code.  And I have no machine that support
memory hot-remove to test the bug now.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

For below functions,

- sparse_add_one_section()
- kmalloc_section_memmap()
- __kmalloc_section_memmap()
- __kfree_section_memmap()

they are always invoked to operate on one memory section, so it is
redundant to always pass a nr_pages parameter, which is the page numbers
in one section.  So we can directly use predefined macro PAGES_PER_SECTION
instead of passing the parameter.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

After commit 9bdac914

 ("sparsemem: Put mem map for one node
together."), vmemmap for one node will be allocated together, its logic
is similar as memory allocation for pageblock flags.  This patch
introduces alloc_usemap_and_memmap to extract the same logic of memory
alloction for pageblock flags and vmemmap.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With CONFIG_MEMORY_HOTREMOVE unset, there is a compile warning:

  mm/sparse.c:755: warning: `clear_hwpoisoned_pages' defined but not used

And Bisecting it ended up pointing to 4edd7cef

 ("mm, hotplug: avoid
compiling memory hotremove functions when disabled").

This is because the commit above put sparse_remove_one_section() within
the protection of CONFIG_MEMORY_HOTREMOVE but the only user of
clear_hwpoisoned_pages() is sparse_remove_one_section(), and it is not
within the protection of CONFIG_MEMORY_HOTREMOVE.

So put clear_hwpoisoned_pages within CONFIG_MEMORY_HOTREMOVE should fix
the warning.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Instead of leaving a hidden trap for the next person who comes along and
wants to add something to mem_section, add a big fat warning about it
needing to be a power-of-2, and insert a BUILD_BUG_ON() in sparse_init()
to catch mistakes.

Right now non-power-of-2 mem_sections cause a number of WARNs at boot
(which don't clearly point to the size of mem_section as an issue), but
the system limps on (temporarily, at least).

This is based upon Dave Hansen's earlier RFC where he ran into the same
issue:
	"sparsemem: fix boot when SECTIONS_PER_ROOT is not power-of-2"
	http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/03077.html

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The ret variable is not used in the function, so remove it and
directly return 0 at the end of the function.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

__remove_pages() is only necessary for CONFIG_MEMORY_HOTREMOVE.  PowerPC
pseries will return -EOPNOTSUPP if unsupported.

Adding an #ifdef causes several other functions it depends on to also
become unnecessary, which saves in .text when disabled (it's disabled in
most defconfigs besides powerpc, including x86).  remove_memory_block()
becomes static since it is not referenced outside of
drivers/base/memory.c.

Build tested on x86 and powerpc with CONFIG_MEMORY_HOTREMOVE both enabled
and disabled.
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The sparse code, when asking the architecture to populate the vmemmap,
specifies the section range as a starting page and a number of pages.

This is an awkward interface, because none of the arch-specific code
actually thinks of the range in terms of 'struct page' units and always
translates it to bytes first.

In addition, later patches mix huge page and regular page backing for
the vmemmap.  For this, they need to call vmemmap_populate_basepages()
on sub-section ranges with PAGE_SIZE and PMD_SIZE in mind.  But these
are not necessarily multiples of the 'struct page' size and so this unit
is too coarse.

Just translate the section range into bytes once in the generic sparse
code, then pass byte ranges down the stack.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Bernhard Schmidt <Bernhard.Schmidt@lrz.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: David S. Miller <davem@davemloft.net>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Since MCE is an x86 concept, and this code is in mm/, it would be better
to use the name num_poisoned_pages instead of mce_bad_pages.

[akpm@linux-foundation.org: fix mm/sparse.c]
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Suggested-by: Borislav Petkov <bp@alien8.de>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

usemap could also be allocated as compound pages.  Should also consider
compound pages when freeing memmap.

If we don't fix it, there could be problems when we free vmemmap
pagetables which are stored in compound pages.  The old pagetables will
not be freed properly, and when we add the memory again, no new
pagetable will be created.  And the old pagetable entry is used, than
the kernel will panic.

The call trace is like the following:

  BUG: unable to handle kernel paging request at ffffea0040000000
  IP: [<ffffffff816a483f>] sparse_add_one_section+0xef/0x166
  PGD 7ff7d4067 PUD 78e035067 PMD 78e11d067 PTE 0
  Oops: 0002 [#1] SMP
  Modules linked in: ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_CHECKSUM iptable_mangle iptable_filter ip_tables bridge stp llc sunrpc binfmt_misc dm_mirror dm_region_hash dm_log dm_mod vhost_net macvtap macvlan tun uinput iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm crc32c_intel microcode pcspkr sg lpc_ich mfd_core i2c_i801 i2c_core i7core_edac edac_core ioatdma e1000e igb dca ptp pps_core sd_mod crc_t10dif megaraid_sas mptsas mptscsih mptbase scsi_transport_sas scsi_mod
  CPU 0
  Pid: 4, comm: kworker/0:0 Tainted: G        W 3.8.0-rc3-phy-hot-remove+ #3 FUJITSU-SV PRIMEQUEST 1800E/SB
  RIP: 0010:[<ffffffff816a483f>]  [<ffffffff816a483f>] sparse_add_one_section+0xef/0x166
  RSP: 0018:ffff8807bdcb35d8  EFLAGS: 00010006
  RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000200000
  RDX: ffff88078df01148 RSI: 0000000000000282 RDI: ffffea0040000000
  RBP: ffff8807bdcb3618 R08: 4cf05005b019467a R09: 0cd98fa09631467a
  R10: 0000000000000000 R11: 0000000000030e20 R12: 0000000000008000
  R13: ffffea0040000000 R14: ffff88078df66248 R15: ffff88078ea13b10
  FS:  0000000000000000(0000) GS:ffff8807c1a00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: ffffea0040000000 CR3: 0000000001c0c000 CR4: 00000000000007f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Process kworker/0:0 (pid: 4, threadinfo ffff8807bdcb2000, task ffff8807bde18000)
  Call Trace:
    __add_pages+0x85/0x120
    arch_add_memory+0x71/0xf0
    add_memory+0xd6/0x1f0
    acpi_memory_device_add+0x170/0x20c
    acpi_device_probe+0x50/0x18a
    really_probe+0x6c/0x320
    driver_probe_device+0x47/0xa0
    __device_attach+0x53/0x60
    bus_for_each_drv+0x6c/0xa0
    device_attach+0xa8/0xc0
    bus_probe_device+0xb0/0xe0
    device_add+0x301/0x570
    device_register+0x1e/0x30
    acpi_device_register+0x1d8/0x27c
    acpi_add_single_object+0x1df/0x2b9
    acpi_bus_check_add+0x112/0x18f
    acpi_ns_walk_namespace+0x105/0x255
    acpi_walk_namespace+0xcf/0x118
    acpi_bus_scan+0x5b/0x7c
    acpi_bus_add+0x2a/0x2c
    container_notify_cb+0x112/0x1a9
    acpi_ev_notify_dispatch+0x46/0x61
    acpi_os_execute_deferred+0x27/0x34
    process_one_work+0x20e/0x5c0
    worker_thread+0x12e/0x370
    kthread+0xee/0x100
    ret_from_fork+0x7c/0xb0
  Code: 00 00 48 89 df 48 89 45 c8 e8 3e 71 b1 ff 48 89 c2 48 8b 75 c8 b8 ef ff ff ff f6 02 01 75 4b 49 63 cc 31 c0 4c 89 ef 48 c1 e1 06 <f3> aa 48 8b 02 48 83 c8 01 48 85 d2 48 89 02 74 29 a8 01 74 25
  RIP  [<ffffffff816a483f>] sparse_add_one_section+0xef/0x166
   RSP <ffff8807bdcb35d8>
  CR2: ffffea0040000000
  ---[ end trace e7f94e3a34c442d4 ]---
  Kernel panic - not syncing: Fatal exception
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Introduce a new API vmemmap_free() to free and remove vmemmap
pagetables.  Since pagetable implements are different, each architecture
has to provide its own version of vmemmap_free(), just like
vmemmap_populate().

Note: vmemmap_free() is not implemented for ia64, ppc, s390, and sparc.

[mhocko@suse.cz: fix implicit declaration of remove_pagetable]
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In __remove_section(), we locked pgdat_resize_lock when calling
sparse_remove_one_section().  This lock will disable irq.  But we don't
need to lock the whole function.  If we do some work to free pagetables
in free_section_usemap(), we need to call flush_tlb_all(), which need
irq enabled.  Otherwise the WARN_ON_ONCE() in smp_call_function_many()
will be triggered.

If we lock the whole sparse_remove_one_section(), then we come to this call trace:

  ------------[ cut here ]------------
  WARNING: at kernel/smp.c:461 smp_call_function_many+0xbd/0x260()
  Hardware name: PRIMEQUEST 1800E
  ......
  Call Trace:
    smp_call_function_many+0xbd/0x260
    smp_call_function+0x3b/0x50
    on_each_cpu+0x3b/0xc0
    flush_tlb_all+0x1c/0x20
    remove_pagetable+0x14e/0x1d0
    vmemmap_free+0x18/0x20
    sparse_remove_one_section+0xf7/0x100
    __remove_section+0xa2/0xb0
    __remove_pages+0xa0/0xd0
    arch_remove_memory+0x6b/0xc0
    remove_memory+0xb8/0xf0
    acpi_memory_device_remove+0x53/0x96
    acpi_device_remove+0x90/0xb2
    __device_release_driver+0x7c/0xf0
    device_release_driver+0x2f/0x50
    acpi_bus_remove+0x32/0x6d
    acpi_bus_trim+0x91/0x102
    acpi_bus_hot_remove_device+0x88/0x16b
    acpi_os_execute_deferred+0x27/0x34
    process_one_work+0x20e/0x5c0
    worker_thread+0x12e/0x370
    kthread+0xee/0x100
    ret_from_fork+0x7c/0xb0
  ---[ end trace 25e85300f542aa01 ]---
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If sparse memory vmemmap is enabled, we can't free the memory to store
struct page when a memory device is hotremoved, because we may store
struct page in the memory to manage the memory which doesn't belong to
this memory device.  When we hotadded this memory device again, we will
reuse this memory to store struct page, and struct page may contain some
obsolete information, and we will get bad-page state:

  init_memory_mapping: [mem 0x80000000-0x9fffffff]
  Built 2 zonelists in Node order, mobility grouping on.  Total pages: 547617
  Policy zone: Normal
  BUG: Bad page state in process bash  pfn:9b6dc
  page:ffffea0002200020 count:0 mapcount:0 mapping:          (null) index:0xfdfdfdfdfdfdfdfd
  page flags: 0x2fdfdfdfd5df9fd(locked|referenced|uptodate|dirty|lru|active|slab|owner_priv_1|private|private_2|writeback|head|tail|swapcache|reclaim|swapbacked|unevictable|uncached|compound_lock)
  Modules linked in: netconsole acpiphp pci_hotplug acpi_memhotplug loop kvm_amd kvm microcode tpm_tis tpm tpm_bios evdev psmouse serio_raw i2c_piix4 i2c_core parport_pc parport processor button thermal_sys ext3 jbd mbcache sg sr_mod cdrom ata_generic virtio_net ata_piix virtio_blk libata virtio_pci virtio_ring virtio scsi_mod
  Pid: 988, comm: bash Not tainted 3.6.0-rc7-guest #12
  Call Trace:
   [<ffffffff810e9b30>] ? bad_page+0xb0/0x100
   [<ffffffff810ea4c3>] ? free_pages_prepare+0xb3/0x100
   [<ffffffff810ea668>] ? free_hot_cold_page+0x48/0x1a0
   [<ffffffff8112cc08>] ? online_pages_range+0x68/0xa0
   [<ffffffff8112cba0>] ? __online_page_increment_counters+0x10/0x10
   [<ffffffff81045561>] ? walk_system_ram_range+0x101/0x110
   [<ffffffff814c4f95>] ? online_pages+0x1a5/0x2b0
   [<ffffffff8135663d>] ? __memory_block_change_state+0x20d/0x270
   [<ffffffff81356756>] ? store_mem_state+0xb6/0xf0
   [<ffffffff8119e482>] ? sysfs_write_file+0xd2/0x160
   [<ffffffff8113769a>] ? vfs_write+0xaa/0x160
   [<ffffffff81137977>] ? sys_write+0x47/0x90
   [<ffffffff814e2f25>] ? async_page_fault+0x25/0x30
   [<ffffffff814ea239>] ? system_call_fastpath+0x16/0x1b
  Disabling lock debugging due to kernel taint

This patch clears the memory to store struct page to avoid unexpected error.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reported-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When we hotremove a memory device, we will free the memory to store struct
page.  If the page is hwpoisoned page, we should decrease mce_bad_pages.

[akpm@linux-foundation.org: cleanup ifdefs]
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I enable CONFIG_DEBUG_VIRTUAL and CONFIG_SPARSEMEM_VMEMMAP, when doing
memory hotremove, there is a kernel BUG at arch/x86/mm/physaddr.c:20.

It is caused by free_section_usemap()->virt_to_page(), virt_to_page() is
only used for kernel direct mapping address, but sparse-vmemmap uses
vmemmap address, so it is going wrong here.

  ------------[ cut here ]------------
  kernel BUG at arch/x86/mm/physaddr.c:20!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: acpihp_drv acpihp_slot edd cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf fuse vfat fat loop dm_mod coretemp kvm crc32c_intel ipv6 ixgbe igb iTCO_wdt i7core_edac edac_core pcspkr iTCO_vendor_support ioatdma microcode joydev sr_mod i2c_i801 dca lpc_ich mfd_core mdio tpm_tis i2c_core hid_generic tpm cdrom sg tpm_bios rtc_cmos button ext3 jbd mbcache usbhid hid uhci_hcd ehci_hcd usbcore usb_common sd_mod crc_t10dif processor thermal_sys hwmon scsi_dh_alua scsi_dh_hp_sw scsi_dh_rdac scsi_dh_emc scsi_dh ata_generic ata_piix libata megaraid_sas scsi_mod
  CPU 39
  Pid: 6454, comm: sh Not tainted 3.7.0-rc1-acpihp-final+ #45 QCI QSSC-S4R/QSSC-S4R
  RIP: 0010:[<ffffffff8103c908>]  [<ffffffff8103c908>] __phys_addr+0x88/0x90
  RSP: 0018:ffff8804440d7c08  EFLAGS: 00010006
  RAX: 0000000000000006 RBX: ffffea0012000000 RCX: 000000000000002c
  ...
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Reviewd-by: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sparse_index_init() uses the index_init_lock spinlock to protect root
mem_section assignment.  The lock is not necessary anymore because the
function is called only during boot (during paging init which is executed
only from a single CPU) and from the hotplug code (by add_memory() via
arch_add_memory()) which uses mem_hotplug_mutex.

The lock was introduced by 28ae55c9 ("sparsemem extreme: hotplug
preparation") and sparse_index_init() was used only during boot at that
time.

Later when the hotplug code (and add_memory()) was introduced there was no
synchronization so it was possible to online more sections from the same
root probably (though I am not 100% sure about that).  The first
synchronization has been added by 6ad696d2 ("mm: allow memory hotplug and
hibernation in the same kernel") which was later replaced by the
mem_hotplug_mutex - 20d6c96b

 ("mem-hotplug: introduce
{un}lock_memory_hotplug()").

Let's remove the lock as it is not needed and it makes the code more
confusing.

[mhocko@suse.cz: changelog]
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

__section_nr() was implemented to retrieve the corresponding memory
section number according to its descriptor.  It's possible that the
specified memory section descriptor doesn't exist in the global array.  So
add more checking on that and report an error for a wrong case.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With CONFIG_SPARSEMEM_EXTREME, the two levels of memory section
descriptors are allocated from slab or bootmem.  When allocating from
slab, let slab/bootmem allocator clear the memory chunk.  We needn't clear
it explicitly.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

On architectures with CONFIG_HUGETLB_PAGE_SIZE_VARIABLE set, such as
Itanium, pageblock_order is a variable with default value of 0.  It's set
to the right value by set_pageblock_order() in function
free_area_init_core().

But pageblock_order may be used by sparse_init() before free_area_init_core()
is called along path:
sparse_init()
    ->sparse_early_usemaps_alloc_node()
	->usemap_size()
	    ->SECTION_BLOCKFLAGS_BITS
		->((1UL << (PFN_SECTION_SHIFT - pageblock_order)) *
NR_PAGEBLOCK_BITS)

The uninitialized pageblock_size will cause memory wasting because
usemap_size() returns a much bigger value then it's really needed.

For example, on an Itanium platform,
sparse_init() pageblock_order=0 usemap_size=24576
free_area_init_core() before pageblock_order=0, usemap_size=24576
free_area_init_core() after pageblock_order=12, usemap_size=8

That means 24K memory has been wasted for each section, so fix it by calling
set_pageblock_order() from sparse_init().
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Keping Chen <chenkeping@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

After commit f5bf18fa ("bootmem/sparsemem: remove limit constraint
in alloc_bootmem_section"), usemap allocations may easily be placed
outside the optimal section that holds the node descriptor, even if
there is space available in that section.  This results in unnecessary
hotplug dependencies that need to have the node unplugged before the
section holding the usemap.

The reason is that the bootmem allocator doesn't guarantee a linear
search starting from the passed allocation goal but may start out at a
much higher address absent an upper limit.

Fix this by trying the allocation with the limit at the section end,
then retry without if that fails.  This keeps the fix from f5bf18fa


of not panicking if the allocation does not fit in the section, but
still makes sure to try to stay within the section at first.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>	[3.3.x, 3.4.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 238305bb

 ("mm: remove sparsemem allocation details from the
bootmem allocator") introduced a bug in the allocation goal calculation
that put section usemaps not in the same section as the node
descriptors, creating unnecessary hotplug dependencies between them:

  node 0 must be removed before remove section 16399
  node 1 must be removed before remove section 16399
  node 2 must be removed before remove section 16399
  node 3 must be removed before remove section 16399
  node 4 must be removed before remove section 16399
  node 5 must be removed before remove section 16399
  node 6 must be removed before remove section 16399

The reason is that it applies PAGE_SECTION_MASK to the physical address
of the node descriptor when finding a suitable place to put the usemap,
when this mask is actually intended to be used with PFNs.  Because the
PFN mask is wider, the target address will point beyond the wanted
section holding the node descriptor and the node must be offlined before
the section holding the usemap can go.

Fix this by extending the mask to address width before use.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

alloc_bootmem_section() derives allocation area constraints from the
specified sparsemem section.  This is a bit specific for a generic memory
allocator like bootmem, though, so move it over to sparsemem.

As __alloc_bootmem_node_nopanic() already retries failed allocations with
relaxed area constraints, the fallback code in sparsemem.c can be removed
and the code becomes a bit more compact overall.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

While testing AMS (Active Memory Sharing) / CMO (Cooperative Memory
Overcommit) on powerpc, we tripped the following:

  kernel BUG at mm/bootmem.c:483!
  cpu 0x0: Vector: 700 (Program Check) at [c000000000c03940]
      pc: c000000000a62bd8: .alloc_bootmem_core+0x90/0x39c
      lr: c000000000a64bcc: .sparse_early_usemaps_alloc_node+0x84/0x29c
      sp: c000000000c03bc0
     msr: 8000000000021032
    current = 0xc000000000b0cce0
    paca    = 0xc000000001d80000
      pid   = 0, comm = swapper
  kernel BUG at mm/bootmem.c:483!
  enter ? for help
  [c000000000c03c80] c000000000a64bcc
  .sparse_early_usemaps_alloc_node+0x84/0x29c
  [c000000000c03d50] c000000000a64f10 .sparse_init+0x12c/0x28c
  [c000000000c03e20] c000000000a474f4 .setup_arch+0x20c/0x294
  [c000000000c03ee0] c000000000a4079c .start_kernel+0xb4/0x460
  [c000000000c03f90] c000000000009670 .start_here_common+0x1c/0x2c

This is

        BUG_ON(limit && goal + size > limit);

and after some debugging, it seems that

	goal = 0x7ffff000000
	limit = 0x80000000000

and sparse_early_usemaps_alloc_node ->
sparse_early_usemaps_alloc_pgdat_section calls

	return alloc_bootmem_section(usemap_size() * count, section_nr);

This is on a system with 8TB available via the AMS pool, and as a quirk
of AMS in firmware, all of that memory shows up in node 0.  So, we end
up with an allocation that will fail the goal/limit constraints.

In theory, we could "fall-back" to alloc_bootmem_node() in
sparse_early_usemaps_alloc_node(), but since we actually have HOTREMOVE
defined, we'll BUG_ON() instead.  A simple solution appears to be to
unconditionally remove the limit condition in alloc_bootmem_section,
meaning allocations are allowed to cross section boundaries (necessary
for systems of this size).

Johannes Weiner pointed out that if alloc_bootmem_section() no longer
guarantees section-locality, we need check_usemap_section_nr() to print
possible cross-dependencies between node descriptors and the usemaps
allocated through it.  That makes the two loops in
sparse_early_usemaps_alloc_node() identical, so re-factor the code a
bit.

[akpm@linux-foundation.org: code simplification]
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Anton Blanchard <anton@au1.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ben Herrenschmidt <benh@kernel.crashing.org>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: <stable@vger.kernel.org>	[3.3.1]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The files changed within are only using the EXPORT_SYMBOL
macro variants.  They are not using core modular infrastructure
and hence don't need module.h but only the export.h header.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

These uses are read-only and in a subsequent patch I have a const struct
page in my hand...

[akpm@linux-foundation.org: fix warnings in lowmem_page_address()]
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

PG_buddy can be converted to _mapcount == -2.  So the PG_compound_lock can
be added to page->flags without overflowing (because of the sparse section
bits increasing) with CONFIG_X86_PAE=y and CONFIG_X86_PAT=y.  This also
has to move the memory hotplug code from _mapcount to lru.next to avoid
any risk of clashes.  We can't use lru.next for PG_buddy removal, but
memory hotplug can use lru.next even more easily than the mapcount
instead.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We need to put mem_map high when virtual memmap is not used.

before this patch
free mem pfn range on first node:
[    0.000000]  19 - 1f
[    0.000000]  28 40 - 80 95
[    0.000000]  702 740 - 1000 1000
[    0.000000]  347c - 347e
[    0.000000]  34e7 3500 - 3b80 3b8b
[    0.000000]  73b8b 73bc0 - 73c00 73c00
[    0.000000]  73ddd - 73e00
[    0.000000]  73fdd - 74000
[    0.000000]  741dd - 74200
[    0.000000]  743dd - 74400
[    0.000000]  745dd - 74600
[    0.000000]  747dd - 74800
[    0.000000]  749dd - 74a00
[    0.000000]  74bdd - 74c00
[    0.000000]  74ddd - 74e00
[    0.000000]  74fdd - 75000
[    0.000000]  751dd - 75200
[    0.000000]  753dd - 75400
[    0.000000]  755dd - 75600
[    0.000000]  757dd - 75800
[    0.000000]  759dd - 75a00
[    0.000000]  79bdd 79c00 - 7d540 7d550
[    0.000000]  7f745 - 7f750
[    0.000000]  10000b 100040 - 2080000 2080000
so only 79c00 - 7d540 are major free block under 4g...

after this patch, we will get
[    0.000000]  19 - 1f
[    0.000000]  28 40 - 80 95
[    0.000000]  702 740 - 1000 1000
[    0.000000]  347c - 347e
[    0.000000]  34e7 3500 - 3600 3600
[    0.000000]  37dd - 3800
[    0.000000]  39dd - 3a00
[    0.000000]  3bdd - 3c00
[    0.000000]  3ddd - 3e00
[    0.000000]  3fdd - 4000
[    0.000000]  41dd - 4200
[    0.000000]  43dd - 4400
[    0.000000]  45dd - 4600
[    0.000000]  47dd - 4800
[    0.000000]  49dd - 4a00
[    0.000000]  4bdd - 4c00
[    0.000000]  4ddd - 4e00
[    0.000000]  4fdd - 5000
[    0.000000]  51dd - 5200
[    0.000000]  53dd - 5400
[    0.000000]  95dd 9600 - 7d540 7d550
[    0.000000]  7f745 - 7f750
[    0.000000]  17000b 170040 - 2080000 2080000
we will have 9600 - 7d540 for major free block...

sparse-vmemmap path already used __alloc_bootmem_node_high()
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py



The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

Stephen reported:
build (powerpc
ppc64_defconfig) produced these warnings:

mm/sparse.c: In function 'sparse_init':
mm/sparse.c:488: warning: unused variable 'map_count'
mm/sparse.c:484: warning: unused variable 'size2'
mm/sparse.c:481: warning: unused variable 'map_map'
mm/sparse.c: At top level:
mm/sparse.c:442: warning: 'sparse_early_mem_maps_alloc_node' defined but not used

Introduced by commit 9bdac914


("sparsemem: Put mem map for one node together").

Conditionalize the bits appropriately based on the setting of
CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4B895682.1080706@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Add vmemmap_alloc_block_buf for mem map only.

It will fallback to the old way if it cannot get a block that big.

Before this patch, when a node have 128g ram installed, memmap are
split into two parts or more.
[    0.000000]  [ffffea0000000000-ffffea003fffffff] PMD -> [ffff880100600000-ffff88013e9fffff] on node 1
[    0.000000]  [ffffea0040000000-ffffea006fffffff] PMD -> [ffff88013ec00000-ffff88016ebfffff] on node 1
[    0.000000]  [ffffea0070000000-ffffea007fffffff] PMD -> [ffff882000600000-ffff8820105fffff] on node 0
[    0.000000]  [ffffea0080000000-ffffea00bfffffff] PMD -> [ffff882010800000-ffff8820507fffff] on node 0
[    0.000000]  [ffffea00c0000000-ffffea00dfffffff] PMD -> [ffff882050a00000-ffff8820709fffff] on node 0
[    0.000000]  [ffffea00e0000000-ffffea00ffffffff] PMD -> [ffff884000600000-ffff8840205fffff] on node 2
[    0.000000]  [ffffea0100000000-ffffea013fffffff] PMD -> [ffff884020800000-ffff8840607fffff] on node 2
[    0.000000]  [ffffea0140000000-ffffea014fffffff] PMD -> [ffff884060a00000-ffff8840709fffff] on node 2
[    0.000000]  [ffffea0150000000-ffffea017fffffff] PMD -> [ffff886000600000-ffff8860305fffff] on node 3
[    0.000000]  [ffffea0180000000-ffffea01bfffffff] PMD -> [ffff886030800000-ffff8860707fffff] on node 3
[    0.000000]  [ffffea01c0000000-ffffea01ffffffff] PMD -> [ffff888000600000-ffff8880405fffff] on node 4
[    0.000000]  [ffffea0200000000-ffffea022fffffff] PMD -> [ffff888040800000-ffff8880707fffff] on node 4
[    0.000000]  [ffffea0230000000-ffffea023fffffff] PMD -> [ffff88a000600000-ffff88a0105fffff] on node 5
[    0.000000]  [ffffea0240000000-ffffea027fffffff] PMD -> [ffff88a010800000-ffff88a0507fffff] on node 5
[    0.000000]  [ffffea0280000000-ffffea029fffffff] PMD -> [ffff88a050a00000-ffff88a0709fffff] on node 5
[    0.000000]  [ffffea02a0000000-ffffea02bfffffff] PMD -> [ffff88c000600000-ffff88c0205fffff] on node 6
[    0.000000]  [ffffea02c0000000-ffffea02ffffffff] PMD -> [ffff88c020800000-ffff88c0607fffff] on node 6
[    0.000000]  [ffffea0300000000-ffffea030fffffff] PMD -> [ffff88c060a00000-ffff88c0709fffff] on node 6
[    0.000000]  [ffffea0310000000-ffffea033fffffff] PMD -> [ffff88e000600000-ffff88e0305fffff] on node 7
[    0.000000]  [ffffea0340000000-ffffea037fffffff] PMD -> [ffff88e030800000-ffff88e0707fffff] on node 7

after patch will get
[    0.000000]  [ffffea0000000000-ffffea006fffffff] PMD -> [ffff880100200000-ffff88016e5fffff] on node 0
[    0.000000]  [ffffea0070000000-ffffea00dfffffff] PMD -> [ffff882000200000-ffff8820701fffff] on node 1
[    0.000000]  [ffffea00e0000000-ffffea014fffffff] PMD -> [ffff884000200000-ffff8840701fffff] on node 2
[    0.000000]  [ffffea0150000000-ffffea01bfffffff] PMD -> [ffff886000200000-ffff8860701fffff] on node 3
[    0.000000]  [ffffea01c0000000-ffffea022fffffff] PMD -> [ffff888000200000-ffff8880701fffff] on node 4
[    0.000000]  [ffffea0230000000-ffffea029fffffff] PMD -> [ffff88a000200000-ffff88a0701fffff] on node 5
[    0.000000]  [ffffea02a0000000-ffffea030fffffff] PMD -> [ffff88c000200000-ffff88c0701fffff] on node 6
[    0.000000]  [ffffea0310000000-ffffea037fffffff] PMD -> [ffff88e000200000-ffff88e0701fffff] on node 7

-v2: change buf to vmemmap_buf instead according to Ingo
     also add CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER according to Ingo
-v3: according to Andrew, use sizeof(name) instead of hard coded 15
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-19-git-send-email-yinghai@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>