1. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard...
      b2441318
  2. 07 Sep, 2017 2 commits
    • Michal Hocko's avatar
      mm, memory_hotplug: remove zone restrictions · c6f03e29
      Michal Hocko authored
      Historically we have enforced that any kernel zone (e.g ZONE_NORMAL) has
      to precede the Movable zone in the physical memory range.  The purpose
      of the movable zone is, however, not bound to any physical memory
      restriction.  It merely defines a class of migrateable and reclaimable
      memory.
      
      There are users (e.g.  CMA) who might want to reserve specific physical
      memory ranges for their own purpose.  Moreover our pfn walkers have to
      be prepared for zones overlapping in the physical range already because
      we do support interleaving NUMA nodes and therefore zones can interleave
      as well.  This means we can allow each memory block to be associated
      with a different zone.
      
      Loosen the current onlining semantic and allow explicit onlining type on
      any memblock.  That means that online_{kernel,movable} will be allowed
      regardless of the physical address of the memblock as long as it is
      offline of course.  This might result in moveble zone overlapping with
      other kernel zones.  Default onlining then becomes a bit tricky but
      still sensible.  echo online > memoryXY/state will online the given
      block to
      
      	1) the default zone if the given range is outside of any zone
      	2) the enclosing zone if such a zone doesn't interleave with
      	   any other zone
              3) the default zone if more zones interleave for this range
      
      where default zone is movable zone only if movable_node is enabled
      otherwise it is a kernel zone.
      
      Here is an example of the semantic with (movable_node is not present but
      it work in an analogous way). We start with following memblocks, all of
      them offline:
      
        memory34/valid_zones:Normal Movable
        memory35/valid_zones:Normal Movable
        memory36/valid_zones:Normal Movable
        memory37/valid_zones:Normal Movable
        memory38/valid_zones:Normal Movable
        memory39/valid_zones:Normal Movable
        memory40/valid_zones:Normal Movable
        memory41/valid_zones:Normal Movable
      
      Now, we online block 34 in default mode and block 37 as movable
      
        root@test1:/sys/devices/system/node/node1# echo online > memory34/state
        root@test1:/sys/devices/system/node/node1# echo online_movable > memory37/state
        memory34/valid_zones:Normal
        memory35/valid_zones:Normal Movable
        memory36/valid_zones:Normal Movable
        memory37/valid_zones:Movable
        memory38/valid_zones:Normal Movable
        memory39/valid_zones:Normal Movable
        memory40/valid_zones:Normal Movable
        memory41/valid_zones:Normal Movable
      
      As we can see all other blocks can still be onlined both into Normal and
      Movable zones and the Normal is default because the Movable zone spans
      only block37 now.
      
        root@test1:/sys/devices/system/node/node1# echo online_movable > memory41/state
        memory34/valid_zones:Normal
        memory35/valid_zones:Normal Movable
        memory36/valid_zones:Normal Movable
        memory37/valid_zones:Movable
        memory38/valid_zones:Movable Normal
        memory39/valid_zones:Movable Normal
        memory40/valid_zones:Movable Normal
        memory41/valid_zones:Movable
      
      Now the default zone for blocks 37-41 has changed because movable zone
      spans that range.
      
        root@test1:/sys/devices/system/node/node1# echo online_kernel > memory39/state
        memory34/valid_zones:Normal
        memory35/valid_zones:Normal Movable
        memory36/valid_zones:Normal Movable
        memory37/valid_zones:Movable
        memory38/valid_zones:Normal Movable
        memory39/valid_zones:Normal
        memory40/valid_zones:Movable Normal
        memory41/valid_zones:Movable
      
      Note that the block 39 now belongs to the zone Normal and so block38
      falls into Normal by default as well.
      
      For completness
      
        root@test1:/sys/devices/system/node/node1# for i in memory[34]?
        do
      	echo online > $i/state 2>/dev/null
        done
      
        memory34/valid_zones:Normal
        memory35/valid_zones:Normal
        memory36/valid_zones:Normal
        memory37/valid_zones:Movable
        memory38/valid_zones:Normal
        memory39/valid_zones:Normal
        memory40/valid_zones:Movable
        memory41/valid_zones:Movable
      
      Implementation wise the change is quite straightforward.  We can get rid
      of allow_online_pfn_range altogether.  online_pages allows only offline
      nodes already.  The original default_zone_for_pfn will become
      default_kernel_zone_for_pfn.  New default_zone_for_pfn implements the
      above semantic.  zone_for_pfn_range is slightly reorganized to implement
      kernel and movable online type explicitly and MMOP_ONLINE_KEEP becomes a
      catch all default behavior.
      
      Link: http://lkml.kernel.org/r/20170714121233.16861-3-mhocko@kernel.org
      
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Acked-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Acked-by: default avatarReza Arbab <arbab@linux.vnet.ibm.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
      Cc: Xishi Qiu <qiuxishi@huawei.com>
      Cc: Kani Toshimitsu <toshi.kani@hpe.com>
      Cc: <slaoub@gmail.com>
      Cc: Daniel Kiper <daniel.kiper@oracle.com>
      Cc: Igor Mammedov <imammedo@redhat.com>
      Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: <linux-api@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c6f03e29
    • Michal Hocko's avatar
      mm, memory_hotplug: display allowed zones in the preferred ordering · e5e68930
      Michal Hocko authored
      Prior to commit f1dd2cd1 ("mm, memory_hotplug: do not associate
      hotadded memory to zones until online") we used to allow to change the
      valid zone types of a memory block if it is adjacent to a different zone
      type.
      
      This fact was reflected in memoryNN/valid_zones by the ordering of
      printed zones.  The first one was default (echo online > memoryNN/state)
      and the other one could be onlined explicitly by online_{movable,kernel}.
      
      This behavior was removed by the said patch and as such the ordering was
      not all that important.  In most cases a kernel zone would be default
      anyway.  The only exception is movable_node handled by "mm,
      memory_hotplug: support movable_node for hotpluggable nodes".
      
      Let's reintroduce this behavior again because later patch will remove
      the zone overlap restriction and so user will be allowed to online
      kernel resp.  movable block regardless of its placement.  Original
      behavior will then become significant again because it would be
      non-trivial for users to see what is the default zone to online into.
      
      Implementation is really simple.  Pull out zone selection out of
      move_pfn_range into zone_for_pfn_range helper and use it in
      show_valid_zones to display the zone for default onlining and then both
      kernel and movable if they are allowed.  Default online zone is not
      duplicated.
      
      Link: http://lkml.kernel.org/r/20170714121233.16861-2-mhocko@kernel.org
      
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Acked-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
      Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
      Cc: Xishi Qiu <qiuxishi@huawei.com>
      Cc: Kani Toshimitsu <toshi.kani@hpe.com>
      Cc: <slaoub@gmail.com>
      Cc: Daniel Kiper <daniel.kiper@oracle.com>
      Cc: Igor Mammedov <imammedo@redhat.com>
      Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e5e68930
  3. 06 Jul, 2017 5 commits
    • Michal Hocko's avatar
      mm, memory_hotplug: do not assume ZONE_NORMAL is default kernel zone · c246a213
      Michal Hocko authored
      Heiko Carstens has noticed that he can generate overlapping zones for
      ZONE_DMA and ZONE_NORMAL:
      
        DMA      [mem 0x0000000000000000-0x000000007fffffff]
        Normal   [mem 0x0000000080000000-0x000000017fffffff]
      
        $ cat /sys/devices/system/memory/block_size_bytes
        10000000
        $ cat /sys/devices/system/memory/memory5/valid_zones
        DMA
        $ echo 0 > /sys/devices/system/memory/memory5/online
        $ cat /sys/devices/system/memory/memory5/valid_zones
        Normal
        $ echo 1 > /sys/devices/system/memory/memory5/online
        Normal
      
        $ cat /proc/zoneinfo
        Node 0, zone      DMA
        spanned  524288        <-----
        present  458752
        managed  455078
        start_pfn:           0 <-----
      
        Node 0, zone   Normal
        spanned  720896
        present  589824
        managed  571648
        start_pfn:           327680 <-----
      
      The reason is that we assume that the default zone for kernel onlining
      is ZONE_NORMAL.  This was a simplification introduced by the memory
      hotplug rework and it is easily fixable by checking the range overlap in
      the zone order and considering the first matching zone as the default
      one.  If there is no such zone then assume ZONE_NORMAL as we have been
      doing so far.
      
      Fixes: "mm, memory_hotplug: do not associate hotadded memory to zones until online"
      Link: http://lkml.kernel.org/r/20170601083746.4924-3-mhocko@kernel.org
      
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Reported-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Tested-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c246a213
    • Michal Hocko's avatar
      mm, memory_hotplug: do not associate hotadded memory to zones until online · f1dd2cd1
      Michal Hocko authored
      The current memory hotplug implementation relies on having all the
      struct pages associate with a zone/node during the physical hotplug
      phase (arch_add_memory->__add_pages->__add_section->__add_zone).  In the
      vast majority of cases this means that they are added to ZONE_NORMAL.
      This has been so since 9d99aaa3 ("[PATCH] x86_64: Support memory
      hotadd without sparsemem") and it wasn't a big deal back then because
      movable onlining didn't exist yet.
      
      Much later memory hotplug wanted to (ab)use ZONE_MOVABLE for movable
      onlining 511c2aba ("mm, memory-hotplug: dynamic configure movable
      memory and portion memory") and then things got more complicated.
      Rather than reconsidering the zone association which was no longer
      needed (because the memory hotplug already depended on SPARSEMEM) a
      convoluted semantic of zone shifting has been developed.  Only the
      currently last memblock or the one adjacent to the zone_movable can be
      onlined movable.  This essentially means that the online type changes as
      the new memblocks are added.
      
      Let's simulate memory hot online manually
        $ echo 0x100000000 > /sys/devices/system/memory/probe
        $ grep . /sys/devices/system/memory/memory32/valid_zones
        Normal Movable
      
        $ echo $((0x100000000+(128<<20))) > /sys/devices/system/memory/probe
        $ grep . /sys/devices/system/memory/memory3?/valid_zones
        /sys/devices/system/memory/memory32/valid_zones:Normal
        /sys/devices/system/memory/memory33/valid_zones:Normal Movable
      
        $ echo $((0x100000000+2*(128<<20))) > /sys/devices/system/memory/probe
        $ grep . /sys/devices/system/memory/memory3?/valid_zones
        /sys/devices/system/memory/memory32/valid_zones:Normal
        /sys/devices/system/memory/memory33/valid_zones:Normal
        /sys/devices/system/memory/memory34/valid_zones:Normal Movable
      
        $ echo online_movable > /sys/devices/system/memory/memory34/state
        $ grep . /sys/devices/system/memory/memory3?/valid_zones
        /sys/devices/system/memory/memory32/valid_zones:Normal
        /sys/devices/system/memory/memory33/valid_zones:Normal Movable
        /sys/devices/system/memory/memory34/valid_zones:Movable Normal
      
      This is an awkward semantic because an udev event is sent as soon as the
      block is onlined and an udev handler might want to online it based on
      some policy (e.g.  association with a node) but it will inherently race
      with new blocks showing up.
      
      This patch changes the physical online phase to not associate pages with
      any zone at all.  All the pages are just marked reserved and wait for
      the onlining phase to be associated with the zone as per the online
      request.  There are only two requirements
      
      	- existing ZONE_NORMAL and ZONE_MOVABLE cannot overlap
      
      	- ZONE_NORMAL precedes ZONE_MOVABLE in physical addresses
      
      the latter one is not an inherent requirement and can be changed in the
      future.  It preserves the current behavior and made the code slightly
      simpler.  This is subject to change in future.
      
      This means that the same physical online steps as above will lead to the
      following state: Normal Movable
      
        /sys/devices/system/memory/memory32/valid_zones:Normal Movable
        /sys/devices/system/memory/memory33/valid_zones:Normal Movable
      
        /sys/devices/system/memory/memory32/valid_zones:Normal Movable
        /sys/devices/system/memory/memory33/valid_zones:Normal Movable
        /sys/devices/system/memory/memory34/valid_zones:Normal Movable
      
        /sys/devices/system/memory/memory32/valid_zones:Normal Movable
        /sys/devices/system/memory/memory33/valid_zones:Normal Movable
        /sys/devices/system/memory/memory34/valid_zones:Movable
      
      Implementation:
      The current move_pfn_range is reimplemented to check the above
      requirements (allow_online_pfn_range) and then updates the respective
      zone (move_pfn_range_to_zone), the pgdat and links all the pages in the
      pfn range with the zone/node.  __add_pages is updated to not require the
      zone and only initializes sections in the range.  This allowed to
      simplify the arch_add_memory code (s390 could get rid of quite some of
      code).
      
      devm_memremap_pages is the only user of arch_add_memory which relies on
      the zone association because it only hooks into the memory hotplug only
      half way.  It uses it to associate the new memory with ZONE_DEVICE but
      doesn't allow it to be {on,off}lined via sysfs.  This means that this
      particular code path has to call move_pfn_range_to_zone explicitly.
      
      The original zone shifting code is kept in place and will be removed in
      the follow up patch for an easier review.
      
      Please note that this patch also changes the original behavior when
      offlining a memory block adjacent to another zone (Normal vs.  Movable)
      used to allow to change its movable type.  This will be handled later.
      
      [richard.weiyang@gmail.com: simplify zone_intersects()]
        Link: http://lkml.kernel.org/r/20170616092335.5177-1-richard.weiyang@gmail.com
      [richard.weiyang@gmail.com: remove duplicate call for set_page_links]
        Link: http://lkml.kernel.org/r/20170616092335.5177-2-richard.weiyang@gmail.com
      [akpm@linux-foundation.org: remove unused local `i']
      Link: http://lkml.kernel.org/r/20170515085827.16474-12-mhocko@kernel.org
      
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Signed-off-by: default avatarWei Yang <richard.weiyang@gmail.com>
      Tested-by: default avatarDan Williams <dan.j.williams@intel.com>
      Tested-by: default avatarReza Arbab <arbab@linux.vnet.ibm.com>
      Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # For s390 bits
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: Daniel Kiper <daniel.kiper@oracle.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Igor Mammedov <imammedo@redhat.com>
      Cc: Jerome Glisse <jglisse@redhat.com>
      Cc: Joonsoo Kim <js1304@gmail.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Tobias Regnery <tobias.regnery@gmail.com>
      Cc: Toshi Kani <toshi.kani@hpe.com>
      Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
      Cc: Xishi Qiu <qiuxishi@huawei.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f1dd2cd1
    • Michal Hocko's avatar
      mm, memory_hotplug: consider offline memblocks removable · 8b0662f2
      Michal Hocko authored
      is_pageblock_removable_nolock() relies on having zone association to
      examine all the page blocks to check whether they are movable or free.
      This is just wasting of cycles when the memblock is offline.  Later
      patch in the series will also change the time when the page is
      associated with a zone so we let's bail out early if the memblock is
      offline.
      
      Link: http://lkml.kernel.org/r/20170515085827.16474-7-mhocko@kernel.org
      
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Reported-by: default avatarIgor Mammedov <imammedo@redhat.com>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Daniel Kiper <daniel.kiper@oracle.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Jerome Glisse <jglisse@redhat.com>
      Cc: Joonsoo Kim <js1304@gmail.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
      Cc: Tobias Regnery <tobias.regnery@gmail.com>
      Cc: Toshi Kani <toshi.kani@hpe.com>
      Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
      Cc: Xishi Qiu <qiuxishi@huawei.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8b0662f2
    • Michal Hocko's avatar
      mm, memory_hotplug: get rid of is_zone_device_section · 1b862aec
      Michal Hocko authored
      Device memory hotplug hooks into regular memory hotplug only half way.
      It needs memory sections to track struct pages but there is no
      need/desire to associate those sections with memory blocks and export
      them to the userspace via sysfs because they cannot be onlined anyway.
      
      This is currently expressed by for_device argument to arch_add_memory
      which then makes sure to associate the given memory range with
      ZONE_DEVICE.  register_new_memory then relies on is_zone_device_section
      to distinguish special memory hotplug from the regular one.  While this
      works now, later patches in this series want to move __add_zone outside
      of arch_add_memory path so we have to come up with something else.
      
      Add want_memblock down the __add_pages path and use it to control
      whether the section->memblock association should be done.
      arch_add_memory then just trivially want memblock for everything but
      for_device hotplug.
      
      remove_memory_section doesn't need is_zone_device_section either.  We
      can simply skip all the memblock specific cleanup if there is no
      memblock for the given section.
      
      This shouldn't introduce any functional change.
      
      Link: http://lkml.kernel.org/r/20170515085827.16474-5-mhocko@kernel.org
      
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Tested-by: default avatarDan Williams <dan.j.williams@intel.com>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: Daniel Kiper <daniel.kiper@oracle.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Igor Mammedov <imammedo@redhat.com>
      Cc: Jerome Glisse <jglisse@redhat.com>
      Cc: Joonsoo Kim <js1304@gmail.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
      Cc: Tobias Regnery <tobias.regnery@gmail.com>
      Cc: Toshi Kani <toshi.kani@hpe.com>
      Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
      Cc: Xishi Qiu <qiuxishi@huawei.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1b862aec
    • Dave Hansen's avatar
      mm, sparsemem: break out of loops early · c4e1be9e
      Dave Hansen authored
      There are a number of times that we loop over NR_MEM_SECTIONS, looking
      for section_present() on each section.  But, when we have very large
      physical address spaces (large MAX_PHYSMEM_BITS), NR_MEM_SECTIONS
      becomes very large, making the loops quite long.
      
      With MAX_PHYSMEM_BITS=46 and a section size of 128MB, the current loops
      are 512k iterations, which we barely notice on modern hardware.  But,
      raising MAX_PHYSMEM_BITS higher (like we will see on systems that
      support 5-level paging) makes this 64x longer and we start to notice,
      especially on slower systems like simulators.  A 10-second delay for
      512k iterations is annoying.  But, a 640- second delay is crippling.
      
      This does not help if we have extremely sparse physical address spaces,
      but those are quite rare.  We expect that most of the "slow" systems
      where this matters will also be quite small and non-sparse.
      
      To fix this, we track the highest section we've ever encountered.  This
      lets us know when we will *never* see another section_present(), and
      lets us break out of the loops earlier.
      
      Doing the whole for_each_present_section_nr() macro is probably
      overkill, but it will ensure that any future loop iterations that we
      grow are more likely to be correct.
      
      Kirrill said "It shaved almost 40 seconds from boot time in qemu with
      5-level paging enabled for me".
      
      Link: http://lkml.kernel.org/r/20170504174434.C45A4735@viggo.jf.intel.com
      
      Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
      Tested-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c4e1be9e
  4. 25 Feb, 2017 1 commit
  5. 03 Feb, 2017 1 commit
    • Toshi Kani's avatar
      base/memory, hotplug: fix a kernel oops in show_valid_zones() · a96dfddb
      Toshi Kani authored
      Reading a sysfs "memoryN/valid_zones" file leads to the following oops
      when the first page of a range is not backed by struct page.
      show_valid_zones() assumes that 'start_pfn' is always valid for
      page_zone().
      
       BUG: unable to handle kernel paging request at ffffea017a000000
       IP: show_valid_zones+0x6f/0x160
      
      This issue may happen on x86-64 systems with 64GiB or more memory since
      their memory block size is bumped up to 2GiB.  [1] An example of such
      systems is desribed below.  0x3240000000 is only aligned by 1GiB and
      this memory block starts from 0x3200000000, which is not backed by
      struct page.
      
       BIOS-e820: [mem 0x0000003240000000-0x000000603fffffff] usable
      
      Since test_pages_in_a_zone() already checks holes, fix this issue by
      extending this function to return 'valid_start' and 'valid_end' for a
      given range.  show_valid_zones() then proceeds with the valid range.
      
      [1] 'Commit bdee237c ("x86: mm: Use 2GB memory block size on
          large-memory x86-64 systems")'
      
      Link: http://lkml.kernel.org/r/20170127222149.30893-3-toshi.kani@hpe.com
      
      Signed-off-by: default avatarToshi Kani <toshi.kani@hpe.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Zhang Zhen <zhenzhang.zhang@huawei.com>
      Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: <stable@vger.kernel.org>	[4.4+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a96dfddb
  6. 25 Jan, 2017 1 commit
    • Yasuaki Ishimatsu's avatar
      memory_hotplug: make zone_can_shift() return a boolean value · 8a1f780e
      Yasuaki Ishimatsu authored
      online_{kernel|movable} is used to change the memory zone to
      ZONE_{NORMAL|MOVABLE} and online the memory.
      
      To check that memory zone can be changed, zone_can_shift() is used.
      Currently the function returns minus integer value, plus integer
      value and 0. When the function returns minus or plus integer value,
      it means that the memory zone can be changed to ZONE_{NORNAL|MOVABLE}.
      
      But when the function returns 0, there are two meanings.
      
      One of the meanings is that the memory zone does not need to be changed.
      For example, when memory is in ZONE_NORMAL and onlined by online_kernel
      the memory zone does not need to be changed.
      
      Another meaning is that the memory zone cannot be changed. When memory
      is in ZONE_NORMAL and onlined by online_movable, the memory zone may
      not be changed to ZONE_MOVALBE due to memory online limitation(see
      Documentation/memory-hotplug.txt). In this case, memory must not be
      onlined.
      
      The patch changes the return type of zone_can_shift() so that memory
      online operation fails when memory zone cannot be changed as follows:
      
      Before applying patch:
         # grep -A 35 "Node 2" /proc/zoneinfo
         Node 2, zone   Normal
         <snip>
            node_scanned  0
                 spanned  8388608
                 present  7864320
                 managed  7864320
         # echo online_movable > memory4097/state
         # grep -A 35 "Node 2" /proc/zoneinfo
         Node 2, zone   Normal
         <snip>
            node_scanned  0
                 spanned  8388608
                 present  8388608
                 managed  8388608
      
         online_movable operation succeeded. But memory is onlined as
         ZONE_NORMAL, not ZONE_MOVABLE.
      
      After applying patch:
         # grep -A 35 "Node 2" /proc/zoneinfo
         Node 2, zone   Normal
         <snip>
            node_scanned  0
                 spanned  8388608
                 present  7864320
                 managed  7864320
         # echo online_movable > memory4097/state
         bash: echo: write error: Invalid argument
         # grep -A 35 "Node 2" /proc/zoneinfo
         Node 2, zone   Normal
         <snip>
            node_scanned  0
                 spanned  8388608
                 present  7864320
                 managed  7864320
      
         online_movable operation failed because of failure of changing
         the memory zone from ZONE_NORMAL to ZONE_MOVABLE
      
      Fixes: df429ac0 ("memory-hotplug: more general validation of zone during online")
      Link: http://lkml.kernel.org/r/2f9c3837-33d7-b6e5-59c0-6ca4372b2d84@gmail.com
      
      Signed-off-by: default avatarYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Reviewed-by: default avatarReza Arbab <arbab@linux.vnet.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8a1f780e
  7. 24 Dec, 2016 1 commit
  8. 29 Nov, 2016 1 commit
    • Kirtika Ruchandani's avatar
      drivers/base/memory.c: Remove unused 'first_page' variable · e22defeb
      Kirtika Ruchandani authored
      Commit 71fbd556 ("memory-hotplug: remove redundant call of page_to_pfn")
      introduced an optimization that rendered 'struct page* first_page'
      useless in memory_block_action(). Compiling with W=1 gives the
      following warning, fix it.
      
      drivers/base/memory.c: In function ‘memory_block_action’:
      drivers/base/memory.c:229:15: warning: variable ‘first_page’ set but not used [-Wunused-but-set-variable]
        struct page *first_page;
                     ^
      
      This is a harmeless warning and is only being fixed to reduce the
      noise with W=1 in the kernel. The call to pfn_to_page() has no side
      effects and is safe to remove.
      
      Fixes: 71fbd556
      
       ("memory-hotplug: remove redundant call of page_to_pfn")
      Cc: Zhang Zhen <zhenzhang.zhang@huawei.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarKirtika Ruchandani <kirtika@chromium.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e22defeb
  9. 08 Oct, 2016 1 commit
  10. 26 Jul, 2016 1 commit
  11. 15 Mar, 2016 1 commit
    • Vitaly Kuznetsov's avatar
      memory-hotplug: add automatic onlining policy for the newly added memory · 31bc3858
      Vitaly Kuznetsov authored
      
      
      Currently, all newly added memory blocks remain in 'offline' state
      unless someone onlines them, some linux distributions carry special udev
      rules like:
      
        SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online"
      
      to make this happen automatically.  This is not a great solution for
      virtual machines where memory hotplug is being used to address high
      memory pressure situations as such onlining is slow and a userspace
      process doing this (udev) has a chance of being killed by the OOM killer
      as it will probably require to allocate some memory.
      
      Introduce default policy for the newly added memory blocks in
      /sys/devices/system/memory/auto_online_blocks file with two possible
      values: "offline" which preserves the current behavior and "online"
      which causes all newly added memory blocks to go online as soon as
      they're added.  The default is "offline".
      Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
      Reviewed-by: default avatarDaniel Kiper <daniel.kiper@oracle.com>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Daniel Kiper <daniel.kiper@oracle.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Tang Chen <tangchen@cn.fujitsu.com>
      Cc: David Vrabel <david.vrabel@citrix.com>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Xishi Qiu <qiuxishi@huawei.com>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Igor Mammedov <imammedo@redhat.com>
      Cc: Kay Sievers <kay@vrfy.org>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      31bc3858
  12. 16 Jan, 2016 1 commit
  13. 15 Jan, 2016 3 commits
    • John Allen's avatar
      drivers/base/memory.c: fix kernel warning during memory hotplug on ppc64 · cb5490a5
      John Allen authored
      Fix a bug where a kernel warning is triggered when performing a memory
      hotplug on ppc64.  This warning may also occur on any architecture that
      uses the memory_probe_store interface.
      
        WARNING: at drivers/base/memory.c:200
        CPU: 9 PID: 13042 Comm: systemd-udevd Not tainted 4.4.0-rc4-00113-g0bd0f1e6
      
      -dirty #7
        NIP [c00000000055e034] pages_correctly_reserved+0x134/0x1b0
        LR [c00000000055e7f8] memory_subsys_online+0x68/0x140
        Call Trace:
          memory_subsys_online+0x68/0x140
          device_online+0xb4/0x120
          store_mem_state+0xb0/0x180
          dev_attr_store+0x34/0x60
          sysfs_kf_write+0x64/0xa0
          kernfs_fop_write+0x17c/0x1e0
          __vfs_write+0x40/0x160
          vfs_write+0xb8/0x200
          SyS_write+0x60/0x110
          system_call+0x38/0xd0
      
      The warning is triggered because there is a udev rule that automatically
      tries to online memory after it has been added.  The udev rule varies
      from distro to distro, but will generally look something like:
      
        SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online"
      
      On any architecture that uses memory_probe_store to reserve memory, the
      udev rule will be triggered after the first section of the block is
      reserved and will subsequently attempt to online the entire block,
      interrupting the memory reservation process and causing the warning.
      This patch modifies memory_probe_store to add a block of memory with a
      single call to add_memory as opposed to looping through and adding each
      section individually.  A single call to add_memory is protected by the
      mem_hotplug mutex which will prevent the udev rule from onlining memory
      until the reservation of the entire block is complete.
      Signed-off-by: default avatarJohn Allen <jallen@linux.vnet.ibm.com>
      Acked-by: default avatarDave Hansen <dave.hansen@intel.com>
      Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cb5490a5
    • Seth Jennings's avatar
      drivers/base/memory.c: rename remove_memory_block() to remove_memory_section() · cc292b0b
      Seth Jennings authored
      
      
      The function removes a section, not a block.  Rename to reflect actual
      functionality.
      Signed-off-by: default avatarSeth Jennings <sjennings@variantweb.net>
      Cc: Andrew Banman <abanman@sgi.com>
      Cc: Daniel J Blueman <daniel@numascale.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Greg KH <greg@kroah.com>
      Cc: Russ Anderson <rja@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cc292b0b
    • Seth Jennings's avatar
      drivers/base/memory.c: clean up section counting · 56c6b5d3
      Seth Jennings authored
      
      
      Right now, section_count is calculated in add_memory_block().  However,
      init_memory_block() increments section_count as well, which, at first,
      seems like it would lead to an off-by-one error.  There is no harm done
      because add_memory_block() immediately overwrites the
      mem->section_count, but it is messy.
      
      This commit moves the increment out of the common init_memory_block()
      (called by both add_memory_block() and register_new_memory()) and adds
      it to register_new_memory().
      Signed-off-by: default avatarSeth Jennings <sjennings@variantweb.net>
      Cc: Andrew Banman <abanman@sgi.com>
      Cc: Daniel J Blueman <daniel@numascale.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Greg KH <greg@kroah.com>
      Cc: Russ Anderson <rja@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      56c6b5d3
  14. 12 Dec, 2015 1 commit
  15. 14 Apr, 2015 2 commits
    • David Rientjes's avatar
      mm, hotplug: fix concurrent memory hot-add deadlock · 30467e0b
      David Rientjes authored
      
      
      There's a deadlock when concurrently hot-adding memory through the probe
      interface and switching a memory block from offline to online.
      
      When hot-adding memory via the probe interface, add_memory() first takes
      mem_hotplug_begin() and then device_lock() is later taken when registering
      the newly initialized memory block.  This creates a lock dependency of (1)
      mem_hotplug.lock (2) dev->mutex.
      
      When switching a memory block from offline to online, dev->mutex is first
      grabbed in device_online() when the write(2) transitions an existing
      memory block from offline to online, and then online_pages() will take
      mem_hotplug_begin().
      
      This creates a lock inversion between mem_hotplug.lock and dev->mutex.
      Vitaly reports that this deadlock can happen when kworker handling a probe
      event races with systemd-udevd switching a memory block's state.
      
      This patch requires the state transition to take mem_hotplug_begin()
      before dev->mutex.  Hot-adding memory via the probe interface creates a
      memory block while holding mem_hotplug_begin(), there is no way to take
      dev->mutex first in this case.
      
      online_pages() and offline_pages() are only called when transitioning
      memory block state.  We now require that mem_hotplug_begin() is taken
      before calling them -- this requires exporting the mem_hotplug_begin() and
      mem_hotplug_done() to generic code.  In all hot-add and hot-remove cases,
      mem_hotplug_begin() is done prior to device_online().  This is all that is
      needed to avoid the deadlock.
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Reported-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
      Tested-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Tang Chen <tangchen@cn.fujitsu.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Zhang Zhen <zhenzhang.zhang@huawei.com>
      Cc: Vladimir Davydov <vdavydov@parallels.com>
      Cc: Wang Nan <wangnan0@huawei.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      30467e0b
    • Sheng Yong's avatar
      memory hotplug: use macro to switch between section and pfn · 19c07d5e
      Sheng Yong authored
      
      
      Use macro section_nr_to_pfn() to switch between section and pfn, instead
      of open-coding it.  No semantic changes.
      Signed-off-by: default avatarSheng Yong <shengyong1@huawei.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      19c07d5e
  16. 25 Mar, 2015 2 commits
  17. 13 Dec, 2014 1 commit
  18. 10 Oct, 2014 1 commit
    • Zhang Zhen's avatar
      memory-hotplug: add sysfs valid_zones attribute · ed2f2400
      Zhang Zhen authored
      
      
      Currently memory-hotplug has two limits:
      
      1. If the memory block is in ZONE_NORMAL, you can change it to
         ZONE_MOVABLE, but this memory block must be adjacent to ZONE_MOVABLE.
      
      2. If the memory block is in ZONE_MOVABLE, you can change it to
         ZONE_NORMAL, but this memory block must be adjacent to ZONE_NORMAL.
      
      With this patch, we can easy to know a memory block can be onlined to
      which zone, and don't need to know the above two limits.
      
      Updated the related Documentation.
      
      [akpm@linux-foundation.org: use conventional comment layout]
      [akpm@linux-foundation.org: fix build with CONFIG_MEMORY_HOTREMOVE=n]
      [akpm@linux-foundation.org: remove unused local zone_prev]
      Signed-off-by: default avatarZhang Zhen <zhenzhang.zhang@huawei.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Toshi Kani <toshi.kani@hp.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Wang Nan <wangnan0@huawei.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ed2f2400
  19. 07 Aug, 2014 3 commits
  20. 04 Jun, 2014 1 commit
  21. 17 Oct, 2013 1 commit
  22. 29 Aug, 2013 2 commits
    • Rafael J. Wysocki's avatar
      driver core / ACPI: Avoid device hot remove locking issues · 5e33bc41
      Rafael J. Wysocki authored
      
      
      device_hotplug_lock is held around the acpi_bus_trim() call in
      acpi_scan_hot_remove() which generally removes devices (it removes
      ACPI device objects at least, but it may also remove "physical"
      device objects through .detach() callbacks of ACPI scan handlers).
      Thus, potentially, device sysfs attributes are removed under that
      lock and to remove those attributes it is necessary to hold the
      s_active references of their directory entries for writing.
      
      On the other hand, the execution of a .show() or .store() callback
      from a sysfs attribute is carried out with that attribute's s_active
      reference held for reading.  Consequently, if any device sysfs
      attribute that may be removed from within acpi_scan_hot_remove()
      through acpi_bus_trim() has a .store() or .show() callback which
      acquires device_hotplug_lock, the execution of that callback may
      deadlock with the removal of the attribute.  [Unfortunately, the
      "online" device attribute of CPUs and memory blocks is one of them.]
      
      To avoid such deadlocks, make all of the sysfs attribute callbacks
      that need to lock device hotplug, for example store_online(), use
      a special function, lock_device_hotplug_sysfs(), to lock device
      hotplug and return the result of that function immediately if it is
      not zero.  This will cause the s_active reference of the directory
      entry in question to be released and the syscall to be restarted
      if device_hotplug_lock cannot be acquired.
      
      [show_online() actually doesn't need to lock device hotplug, but
      it is useful to serialize it with respect to device_offline() and
      device_online() for the same device (in case user space attempts to
      run them concurrently) which can be done with the help of
      device_lock().]
      Reported-by: default avatarYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Reported-and-tested-by: default avatarGu Zheng <guz.fnst@cn.fujitsu.com>
      Suggested-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Acked-by: default avatarToshi Kani <toshi.kani@hp.com>
      5e33bc41
    • Russ Anderson's avatar
      drivers/base/memory.c: fix show_mem_removable() to handle missing sections · 21ea9f5a
      Russ Anderson authored
      
      
      "cat /sys/devices/system/memory/memory*/removable" crashed the system.
      
      The problem is that show_mem_removable() is passing a
      bad pfn to is_mem_section_removable(), which causes
      
          if (!node_online(page_to_nid(page)))
      
      to blow up.  Why is it passing in a bad pfn?
      
      The reason is that show_mem_removable() will loop sections_per_block
      times.  sections_per_block is 16, but mem->section_count is 8,
      indicating holes in this memory block.  Checking that the memory section
      is present before checking to see if the memory section is removable
      fixes the problem.
      
         harp5-sys:~ # cat /sys/devices/system/memory/memory*/removable
         0
         1
         1
         1
         1
         1
         1
         1
         1
         1
         1
         1
         1
         1
         BUG: unable to handle kernel paging request at ffffea00c3200000
         IP: [<ffffffff81117ed1>] is_pageblock_removable_nolock+0x1/0x90
         PGD 83ffd4067 PUD 37bdfce067 PMD 0
         Oops: 0000 [#1] SMP
         Modules linked in: autofs4 binfmt_misc rdma_ucm rdma_cm iw_cm ib_addr ib_srp scsi_transport_srp scsi_tgt ib_ipoib ib_cm ib_uverbs ib_umad iw_cxgb3 cxgb3 mdio mlx4_en mlx4_ib ib_sa mlx4_core ib_mthca ib_mad ib_core fuse nls_iso8859_1 nls_cp437 vfat fat joydev loop hid_generic usbhid hid hwperf(O) numatools(O) dm_mod iTCO_wdt ipv6 iTCO_vendor_support igb i2c_i801 ioatdma i2c_algo_bit ehci_pci pcspkr lpc_ich i2c_core ehci_hcd ptp sg mfd_core dca rtc_cmos pps_core mperf button xhci_hcd sd_mod crc_t10dif usbcore usb_common scsi_dh_emc scsi_dh_hp_sw scsi_dh_alua scsi_dh_rdac scsi_dh gru(O) xvma(O) xfs crc32c libcrc32c thermal sata_nv processor piix mptsas mptscsih scsi_transport_sas mptbase megaraid_sas fan thermal_sys hwmon ext3 jbd ata_piix ahci libahci libata scsi_mod
         CPU: 4 PID: 5991 Comm: cat Tainted: G           O 3.11.0-rc5-rja-uv+ #10
         Hardware name: SGI UV2000/ROMLEY, BIOS SGI UV 2000/3000 series BIOS 01/15/2013
         task: ffff88081f034580 ti: ffff880820022000 task.ti: ffff880820022000
         RIP: 0010:[<ffffffff81117ed1>]  [<ffffffff81117ed1>] is_pageblock_removable_nolock+0x1/0x90
         RSP: 0018:ffff880820023df8  EFLAGS: 00010287
         RAX: 0000000000040000 RBX: ffffea00c3200000 RCX: 0000000000000004
         RDX: ffffea00c30b0000 RSI: 00000000001c0000 RDI: ffffea00c3200000
         RBP: ffff880820023e38 R08: 0000000000000000 R09: 0000000000000001
         R10: 0000000000000000 R11: 0000000000000001 R12: ffffea00c33c0000
         R13: 0000160000000000 R14: 6db6db6db6db6db7 R15: 0000000000000001
         FS:  00007ffff7fb2700(0000) GS:ffff88083fc80000(0000) knlGS:0000000000000000
         CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
         CR2: ffffea00c3200000 CR3: 000000081b954000 CR4: 00000000000407e0
         Call Trace:
           show_mem_removable+0x41/0x70
           dev_attr_show+0x2a/0x60
           sysfs_read_file+0xf7/0x1c0
           vfs_read+0xc8/0x130
           SyS_read+0x5d/0xa0
           system_call_fastpath+0x16/0x1b
      Signed-off-by: default avatarRuss Anderson <rja@sgi.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Reviewed-by: default avatarYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      21ea9f5a
  23. 28 Aug, 2013 1 commit
  24. 21 Aug, 2013 5 commits