1. 21 Jan, 2014 40 commits
    • Joonsoo Kim's avatar
      mm/rmap: use rmap_walk() in page_mkclean() · 9853a407
      Joonsoo Kim authored
      
      
      Now, we have an infrastructure in rmap_walk() to handle difference from
         variants of rmap traversing functions.
      
      So, just use it in page_mkclean().
      
      In this patch, I change following things.
      
      1. remove some variants of rmap traversing functions.
          cf> page_mkclean_file
      2. mechanical change to use rmap_walk() in page_mkclean().
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Hillf Danton <dhillf@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9853a407
    • Joonsoo Kim's avatar
      mm/rmap: use rmap_walk() in page_referenced() · 9f32624b
      Joonsoo Kim authored
      
      
      Now, we have an infrastructure in rmap_walk() to handle difference from
      variants of rmap traversing functions.
      
      So, just use it in page_referenced().
      
      In this patch, I change following things.
      
      1. remove some variants of rmap traversing functions.
      	cf> page_referenced_ksm, page_referenced_anon,
      	page_referenced_file
      
      2. introduce new struct page_referenced_arg and pass it to
         page_referenced_one(), main function of rmap_walk, in order to count
         reference, to store vm_flags and to check finish condition.
      
      3. mechanical change to use rmap_walk() in page_referenced().
      
      [liwanp@linux.vnet.ibm.com: fix BUG at rmap_walk]
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Hillf Danton <dhillf@gmail.com>
      Signed-off-by: default avatarWanpeng Li <liwanp@linux.vnet.ibm.com>
      Cc: Sasha Levin <sasha.levin@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9f32624b
    • Joonsoo Kim's avatar
      mm/rmap: use rmap_walk() in try_to_munlock() · e8351ac9
      Joonsoo Kim authored
      
      
      Now, we have an infrastructure in rmap_walk() to handle difference from
      variants of rmap traversing functions.
      
      So, just use it in try_to_munlock().
      
      In this patch, I change following things.
      
      1. remove some variants of rmap traversing functions.
      	cf> try_to_unmap_ksm, try_to_unmap_anon, try_to_unmap_file
      2. mechanical change to use rmap_walk() in try_to_munlock().
      3. copy and paste comments.
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Hillf Danton <dhillf@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e8351ac9
    • Joonsoo Kim's avatar
      mm/rmap: use rmap_walk() in try_to_unmap() · 52629506
      Joonsoo Kim authored
      
      
      Now, we have an infrastructure in rmap_walk() to handle difference from
      variants of rmap traversing functions.
      
      So, just use it in try_to_unmap().
      
      In this patch, I change following things.
      
      1. enable rmap_walk() if !CONFIG_MIGRATION.
      2. mechanical change to use rmap_walk() in try_to_unmap().
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Hillf Danton <dhillf@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      52629506
    • Joonsoo Kim's avatar
      mm/rmap: extend rmap_walk_xxx() to cope with different cases · 0dd1c7bb
      Joonsoo Kim authored
      
      
      There are a lot of common parts in traversing functions, but there are
      also a little of uncommon parts in it.  By assigning proper function
      pointer on each rmap_walker_control, we can handle these difference
      correctly.
      
      Following are differences we should handle.
      
      1. difference of lock function in anon mapping case
      2. nonlinear handling in file mapping case
      3. prechecked condition:
      	checking memcg in page_referenced(),
      	checking VM_SHARE in page_mkclean()
      	checking temporary vma in try_to_unmap()
      4. exit condition:
      	checking page_mapped() in try_to_unmap()
      
      So, in this patch, I introduce 4 function pointers to handle above
      differences.
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Hillf Danton <dhillf@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0dd1c7bb
    • Joonsoo Kim's avatar
      mm/rmap: make rmap_walk to get the rmap_walk_control argument · 051ac83a
      Joonsoo Kim authored
      
      
      In each rmap traverse case, there is some difference so that we need
      function pointers and arguments to them in order to handle these
      
      For this purpose, struct rmap_walk_control is introduced in this patch,
      and will be extended in following patch.  Introducing and extending are
      separate, because it clarify changes.
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Hillf Danton <dhillf@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      051ac83a
    • Joonsoo Kim's avatar
      mm/rmap: factor lock function out of rmap_walk_anon() · faecd8dd
      Joonsoo Kim authored
      
      
      When we traverse anon_vma, we need to take a read-side anon_lock.  But
      there is subtle difference in the situation so that we can't use same
      method to take a lock in each cases.  Therefore, we need to make
      rmap_walk_anon() taking difference lock function.
      
      This patch is the first step, factoring lock function for anon_lock out
      of rmap_walk_anon().  It will be used in case of removing migration
      entry and in default of rmap_walk_anon().
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Hillf Danton <dhillf@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      faecd8dd
    • Joonsoo Kim's avatar
      mm/rmap: factor nonlinear handling out of try_to_unmap_file() · 0f843c6a
      Joonsoo Kim authored
      
      
      To merge all kinds of rmap traverse functions, try_to_unmap(),
      try_to_munlock(), page_referenced() and page_mkclean(), we need to
      extract common parts and separate out non-common parts.
      
      Nonlinear handling is handled just in try_to_unmap_file() and other rmap
      traverse functions doesn't care of it.  Therfore it is better to factor
      nonlinear handling out of try_to_unmap_file() in order to merge all
      kinds of rmap traverse functions easily.
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Hillf Danton <dhillf@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0f843c6a
    • Joonsoo Kim's avatar
      mm/rmap: recompute pgoff for huge page · b854f711
      Joonsoo Kim authored
      Rmap traversing is used in five different cases, try_to_unmap(),
      try_to_munlock(), page_referenced(), page_mkclean() and
      remove_migration_ptes().  Each one implements its own traversing
      functions for the cases, anon, file, ksm, respectively.  These cause
      lots of duplications and cause maintenance overhead.  They also make
      codes being hard to understand and error-prone.  One example is hugepage
      handling.  There is a code to compute hugepage offset correctly in
      try_to_unmap_file(), but, there isn't a code to compute hugepage offset
      in rmap_walk_file().  These are used pairwise in migration context, but
      we missed to modify pairwise.
      
      To overcome these drawbacks, we should unify these through one unified
      function.  I decide rmap_walk() as main function since it has no
      unnecessity.  And to control behavior of rmap_walk(), I introduce struct
      rmap_walk_control having some function pointers.  These makes
      rmap_walk() working for their specific needs.
      
      This patchset remove a lot of duplicated code as you can see in below
      short-stat and kernel text size also decrease slightly.
      
         text    data     bss     dec     hex filename
        10640       1      16   10657    29a1 mm/rmap.o
        10047       1      16   10064    2750 mm/rmap.o
      
        13823     705    8288   22816    5920 mm/ksm.o
        13199     705    8288   22192    56b0 mm/ksm.o
      
      This patch (of 9):
      
      We have to recompute pgoff if the given page is huge, since result based
      on HPAGE_SIZE is not approapriate for scanning the vma interval tree, as
      shown by commit 36e4f20a ("hugetlb: do not use
      vma_hugecache_offset() for vma_prio_tree_foreach") and commit 369a713e
      
      
      ("rmap: recompute pgoff for unmapping huge page").
      
      To handle both the cases, normal page for page cache and hugetlb page,
      by same way, we can use compound_page().  It returns 0 on non-compound
      page and it also returns proper value on compound page.
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Hillf Danton <dhillf@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b854f711
    • Vladimir Davydov's avatar
      memcg: make memcg_update_cache_sizes() static · 2753b35b
      Vladimir Davydov authored
      
      
      This function is not used outside of memcontrol.c so make it static.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2753b35b
    • Vladimir Davydov's avatar
      memcg: fix kmem_account_flags check in memcg_can_account_kmem() · 1c98dd90
      Vladimir Davydov authored
      
      
      We should start kmem accounting for a memory cgroup only after both its
      kmem limit is set (KMEM_ACCOUNTED_ACTIVE) and related call sites are
      patched (KMEM_ACCOUNTED_ACTIVATED).  Currently memcg_can_account_kmem()
      allows kmem accounting even if only one of the conditions is true.  Fix
      it.
      
      This means that a page might get charged by memcg_kmem_newpage_charge
      which would see its static key patched already but
      memcg_kmem_commit_charge would still see it unpatched and so the charge
      won't be committed.  The result would be charge inconsistency
      (page_cgroup not marked as PageCgroupUsed) and the charge would leak
      because __memcg_kmem_uncharge_pages would ignore it.
      
      [mhocko@suse.cz: augment changelog]
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Glauber Costa <glommer@parallels.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1c98dd90
    • Tang Chen's avatar
      x86, numa, acpi, memory-hotplug: make movable_node have higher priority · b2f3eebe
      Tang Chen authored
      
      
      If users specify the original movablecore=nn@ss boot option, the kernel
      will arrange [ss, ss+nn) as ZONE_MOVABLE.  The kernelcore=nn@ss boot
      option is similar except it specifies ZONE_NORMAL ranges.
      
      Now, if users specify "movable_node" in kernel commandline, the kernel
      will arrange hotpluggable memory in SRAT as ZONE_MOVABLE.  And if users
      do this, all the other movablecore=nn@ss and kernelcore=nn@ss options
      should be ignored.
      
      For those who don't want this, just specify nothing.  The kernel will
      act as before.
      Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
      Signed-off-by: default avatarZhang Yanfei <zhangyanfei@cn.fujitsu.com>
      Reviewed-by: default avatarWanpeng Li <liwanp@linux.vnet.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "Rafael J . Wysocki" <rjw@sisk.pl>
      Cc: Chen Tang <imtangchen@gmail.com>
      Cc: Gong Chen <gong.chen@linux.intel.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jiang Liu <jiang.liu@huawei.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Larry Woodman <lwoodman@redhat.com>
      Cc: Len Brown <lenb@kernel.org>
      Cc: Liu Jiang <jiang.liu@huawei.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Thomas Renninger <trenn@suse.de>
      Cc: Toshi Kani <toshi.kani@hp.com>
      Cc: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
      Cc: Wen Congyang <wency@cn.fujitsu.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b2f3eebe
    • Tang Chen's avatar
      memblock, mem_hotplug: make memblock skip hotpluggable regions if needed · 55ac590c
      Tang Chen authored
      
      
      Linux kernel cannot migrate pages used by the kernel.  As a result,
      hotpluggable memory used by the kernel won't be able to be hot-removed.
      To solve this problem, the basic idea is to prevent memblock from
      allocating hotpluggable memory for the kernel at early time, and arrange
      all hotpluggable memory in ACPI SRAT(System Resource Affinity Table) as
      ZONE_MOVABLE when initializing zones.
      
      In the previous patches, we have marked hotpluggable memory regions with
      MEMBLOCK_HOTPLUG flag in memblock.memory.
      
      In this patch, we make memblock skip these hotpluggable memory regions
      in the default top-down allocation function if movable_node boot option
      is specified.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
      Signed-off-by: default avatarZhang Yanfei <zhangyanfei@cn.fujitsu.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "Rafael J . Wysocki" <rjw@sisk.pl>
      Cc: Chen Tang <imtangchen@gmail.com>
      Cc: Gong Chen <gong.chen@linux.intel.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jiang Liu <jiang.liu@huawei.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Larry Woodman <lwoodman@redhat.com>
      Cc: Len Brown <lenb@kernel.org>
      Cc: Liu Jiang <jiang.liu@huawei.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Thomas Renninger <trenn@suse.de>
      Cc: Toshi Kani <toshi.kani@hp.com>
      Cc: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
      Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
      Cc: Wen Congyang <wency@cn.fujitsu.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      55ac590c
    • Tang Chen's avatar
      acpi, numa, mem_hotplug: mark all nodes the kernel resides un-hotpluggable · a0acda91
      Tang Chen authored
      
      
      At very early time, the kernel have to use some memory such as loading
      the kernel image.  We cannot prevent this anyway.  So any node the
      kernel resides in should be un-hotpluggable.
      Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
      Reviewed-by: default avatarZhang Yanfei <zhangyanfei@cn.fujitsu.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "Rafael J . Wysocki" <rjw@sisk.pl>
      Cc: Chen Tang <imtangchen@gmail.com>
      Cc: Gong Chen <gong.chen@linux.intel.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jiang Liu <jiang.liu@huawei.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Larry Woodman <lwoodman@redhat.com>
      Cc: Len Brown <lenb@kernel.org>
      Cc: Liu Jiang <jiang.liu@huawei.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Thomas Renninger <trenn@suse.de>
      Cc: Toshi Kani <toshi.kani@hp.com>
      Cc: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
      Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
      Cc: Wen Congyang <wency@cn.fujitsu.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a0acda91
    • Tang Chen's avatar
      acpi, numa, mem_hotplug: mark hotpluggable memory in memblock · 05d1d8cb
      Tang Chen authored
      
      
      When parsing SRAT, we know that which memory area is hotpluggable.  So we
      invoke function memblock_mark_hotplug() introduced by previous patch to
      mark hotpluggable memory in memblock.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
      Reviewed-by: default avatarZhang Yanfei <zhangyanfei@cn.fujitsu.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "Rafael J . Wysocki" <rjw@sisk.pl>
      Cc: Chen Tang <imtangchen@gmail.com>
      Cc: Gong Chen <gong.chen@linux.intel.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jiang Liu <jiang.liu@huawei.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Larry Woodman <lwoodman@redhat.com>
      Cc: Len Brown <lenb@kernel.org>
      Cc: Liu Jiang <jiang.liu@huawei.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Thomas Renninger <trenn@suse.de>
      Cc: Toshi Kani <toshi.kani@hp.com>
      Cc: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
      Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
      Cc: Wen Congyang <wency@cn.fujitsu.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      05d1d8cb
    • Tang Chen's avatar
      memblock: make memblock_set_node() support different memblock_type · e7e8de59
      Tang Chen authored
      
      
      [sfr@canb.auug.org.au: fix powerpc build]
      Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
      Reviewed-by: default avatarZhang Yanfei <zhangyanfei@cn.fujitsu.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "Rafael J . Wysocki" <rjw@sisk.pl>
      Cc: Chen Tang <imtangchen@gmail.com>
      Cc: Gong Chen <gong.chen@linux.intel.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jiang Liu <jiang.liu@huawei.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Larry Woodman <lwoodman@redhat.com>
      Cc: Len Brown <lenb@kernel.org>
      Cc: Liu Jiang <jiang.liu@huawei.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Thomas Renninger <trenn@suse.de>
      Cc: Toshi Kani <toshi.kani@hp.com>
      Cc: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
      Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
      Cc: Wen Congyang <wency@cn.fujitsu.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e7e8de59
    • Tang Chen's avatar
      memblock, mem_hotplug: introduce MEMBLOCK_HOTPLUG flag to mark hotpluggable regions · 66b16edf
      Tang Chen authored
      
      
      In find_hotpluggable_memory, once we find out a memory region which is
      hotpluggable, we want to mark them in memblock.memory.  So that we could
      control memblock allocator not to allocte hotpluggable memory for the
      kernel later.
      
      To achieve this goal, we introduce MEMBLOCK_HOTPLUG flag to indicate the
      hotpluggable memory regions in memblock and a function
      memblock_mark_hotplug() to mark hotpluggable memory if we find one.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
      Reviewed-by: default avatarZhang Yanfei <zhangyanfei@cn.fujitsu.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "Rafael J . Wysocki" <rjw@sisk.pl>
      Cc: Chen Tang <imtangchen@gmail.com>
      Cc: Gong Chen <gong.chen@linux.intel.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jiang Liu <jiang.liu@huawei.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Larry Woodman <lwoodman@redhat.com>
      Cc: Len Brown <lenb@kernel.org>
      Cc: Liu Jiang <jiang.liu@huawei.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Thomas Renninger <trenn@suse.de>
      Cc: Toshi Kani <toshi.kani@hp.com>
      Cc: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
      Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
      Cc: Wen Congyang <wency@cn.fujitsu.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      66b16edf
    • Tang Chen's avatar
      memblock, numa: introduce flags field into memblock · 66a20757
      Tang Chen authored
      
      
      There is no flag in memblock to describe what type the memory is.
      Sometimes, we may use memblock to reserve some memory for special usage.
      And we want to know what kind of memory it is.  So we need a way to
      
      In hotplug environment, we want to reserve hotpluggable memory so the
      kernel won't be able to use it.  And when the system is up, we have to
      free these hotpluggable memory to buddy.  So we need to mark these
      memory first.
      
      In order to do so, we need to mark out these special memory in memblock.
      In this patch, we introduce a new "flags" member into memblock_region:
      
         struct memblock_region {
                 phys_addr_t base;
                 phys_addr_t size;
                 unsigned long flags;		/* This is new. */
         #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
                 int nid;
         #endif
         };
      
      This patch does the following things:
      1) Add "flags" member to memblock_region.
      2) Modify the following APIs' prototype:
      	memblock_add_region()
      	memblock_insert_region()
      3) Add memblock_reserve_region() to support reserve memory with flags, and keep
         memblock_reserve()'s prototype unmodified.
      4) Modify other APIs to support flags, but keep their prototype unmodified.
      
      The idea is from Wen Congyang <wency@cn.fujitsu.com> and Liu Jiang <jiang.liu@huawei.com>.
      Suggested-by: default avatarWen Congyang <wency@cn.fujitsu.com>
      Suggested-by: default avatarLiu Jiang <jiang.liu@huawei.com>
      Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
      Reviewed-by: default avatarZhang Yanfei <zhangyanfei@cn.fujitsu.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "Rafael J . Wysocki" <rjw@sisk.pl>
      Cc: Chen Tang <imtangchen@gmail.com>
      Cc: Gong Chen <gong.chen@linux.intel.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jiang Liu <jiang.liu@huawei.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Larry Woodman <lwoodman@redhat.com>
      Cc: Len Brown <lenb@kernel.org>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Thomas Renninger <trenn@suse.de>
      Cc: Toshi Kani <toshi.kani@hp.com>
      Cc: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
      Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      66a20757
    • Grygorii Strashko's avatar
      mm/memblock: debug: correct displaying of upper memory boundary · 931d13f5
      Grygorii Strashko authored
      
      
      Current memblock APIs don't work on 32 PAE or LPAE extension arches
      where the physical memory start address beyond 4GB.  The problem was
      discussed here [3] where Tejun, Yinghai(thanks) proposed a way forward
      with memblock interfaces.  Based on the proposal, this series adds
      necessary memblock interfaces and convert the core kernel code to use
      them.  Architectures already converted to NO_BOOTMEM use these new
      interfaces and other which still uses bootmem, these new interfaces just
      fallback to exiting bootmem APIs.
      
      So no functional change in behavior.  In long run, once all the
      architectures moves to NO_BOOTMEM, we can get rid of bootmem layer
      completely.  This is one step to remove the core code dependency with
      bootmem and also gives path for architectures to move away from bootmem.
      
      Testing is done on ARM architecture with 32 bit ARM LAPE machines with
      normal as well sparse(faked) memory model.
      
      This patch (of 23):
      
      When debugging is enabled (cmdline has "memblock=debug") the memblock
      will display upper memory boundary per each allocated/freed memory range
      wrongly.  For example:
      
       memblock_reserve: [0x0000009e7e8000-0x0000009e7ed000] _memblock_early_alloc_try_nid_nopanic+0xfc/0x12c
      
      The 0x0000009e7ed000 is displayed instead of 0x0000009e7ecfff
      
      Hence, correct this by changing formula used to calculate upper memory
      boundary to (u64)base + size - 1 instead of (u64)base + size everywhere
      in the debug messages.
      Signed-off-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: default avatarSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Acked-by: default avatarTejun Heo <tj@kernel.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      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: 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: Tony Lindgren <tony@atomide.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      931d13f5
    • Davidlohr Bueso's avatar
      mm/mlock: prepare params outside critical region · 1f1cd705
      Davidlohr Bueso authored
      
      
      All mlock related syscalls prepare lock limits, lengths and start
      parameters with the mmap_sem held.  Move this logic outside of the
      critical region.  For the case of mlock, continue incrementing the
      amount already locked by mm->locked_vm with the rwsem taken.
      Signed-off-by: default avatarDavidlohr Bueso <davidlohr@hp.com>
      Cc: Rik van Riel <riel@redhat.com>
      Reviewed-by: default avatarMichel Lespinasse <walken@google.com>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1f1cd705
    • Davidlohr Bueso's avatar
      mm/mmap.c: add mlock_future_check() helper · 363ee17f
      Davidlohr Bueso authored
      
      
      Both do_brk and do_mmap_pgoff verify that we are actually capable of
      locking future pages if the corresponding VM_LOCKED flags are used.
      Encapsulate this logic into a single mlock_future_check() helper
      function.
      Signed-off-by: default avatarDavidlohr Bueso <davidlohr@hp.com>
      Cc: Rik van Riel <riel@redhat.com>
      Reviewed-by: default avatarMichel Lespinasse <walken@google.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      363ee17f
    • Jerome Marchand's avatar
      mm: add overcommit_kbytes sysctl variable · 49f0ce5f
      Jerome Marchand authored
      
      
      Some applications that run on HPC clusters are designed around the
      availability of RAM and the overcommit ratio is fine tuned to get the
      maximum usage of memory without swapping.  With growing memory, the
      1%-of-all-RAM grain provided by overcommit_ratio has become too coarse
      for these workload (on a 2TB machine it represents no less than 20GB).
      
      This patch adds the new overcommit_kbytes sysctl variable that allow a
      much finer grain.
      
      [akpm@linux-foundation.org: coding-style fixes]
      [akpm@linux-foundation.org: fix nommu build]
      Signed-off-by: default avatarJerome Marchand <jmarchan@redhat.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      49f0ce5f
    • Mel Gorman's avatar
      mm, show_mem: remove SHOW_MEM_FILTER_PAGE_COUNT · aec6a888
      Mel Gorman authored
      Commit 4b59e6c4 ("mm, show_mem: suppress page counts in
      non-blockable contexts") introduced SHOW_MEM_FILTER_PAGE_COUNT to
      suppress PFN walks on large memory machines.  Commit c78e9363
      
       ("mm:
      do not walk all of system memory during show_mem") avoided a PFN walk in
      the generic show_mem helper which removes the requirement for
      SHOW_MEM_FILTER_PAGE_COUNT in that case.
      
      This patch removes PFN walkers from the arch-specific implementations
      that report on a per-node or per-zone granularity.  ARM and unicore32
      still do a PFN walk as they report memory usage on each bank which is a
      much finer granularity where the debugging information may still be of
      use.  As the remaining arches doing PFN walks have relatively small
      amounts of memory, this patch simply removes SHOW_MEM_FILTER_PAGE_COUNT.
      
      [akpm@linux-foundation.org: fix parisc]
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: James Bottomley <jejb@parisc-linux.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      aec6a888
    • Jianyu Zhan's avatar
      mm/vmalloc: interchage the implementation of vmalloc_to_{pfn,page} · ece86e22
      Jianyu Zhan authored
      
      
      Currently we are implementing vmalloc_to_pfn() as a wrapper around
      vmalloc_to_page(), which is implemented as follow:
      
       1. walks the page talbes to generates the corresponding pfn,
       2. then converts the pfn to struct page,
       3. returns it.
      
      And vmalloc_to_pfn() re-wraps vmalloc_to_page() to get the pfn.
      
      This seems too circuitous, so this patch reverses the way: implement
      vmalloc_to_page() as a wrapper around vmalloc_to_pfn().  This makes
      vmalloc_to_pfn() and vmalloc_to_page() slightly more efficient.
      
      No functional change.
      Signed-off-by: default avatarJianyu Zhan <nasa4836@gmail.com>
      Cc: Vladimir Murzin <murzin.v@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ece86e22
    • David Rientjes's avatar
      mm, mempolicy: remove unneeded functions for UMA configs · d80be7c7
      David Rientjes authored
      
      
      Mempolicies only exist for CONFIG_NUMA configurations.  Therefore, a
      certain class of functions are unneeded in configurations where
      CONFIG_NUMA is disabled such as functions that duplicate existing
      mempolicies, lookup existing policies, set certain mempolicy traits, or
      test mempolicies for certain attributes.
      
      Remove the unneeded functions so that any future callers get a compile-
      time error and protect their code with CONFIG_NUMA as required.
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d80be7c7
    • Andreas Sandberg's avatar
      mm/hugetlb.c: call MMU notifiers when copying a hugetlb page range · e8569dd2
      Andreas Sandberg authored
      
      
      When copy_hugetlb_page_range() is called to copy a range of hugetlb
      mappings, the secondary MMUs are not notified if there is a protection
      downgrade, which breaks COW semantics in KVM.
      
      This patch adds the necessary MMU notifier calls.
      Signed-off-by: default avatarAndreas Sandberg <andreas@sandberg.pp.se>
      Acked-by: default avatarSteve Capper <steve.capper@linaro.org>
      Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e8569dd2
    • Zhi Yong Wu's avatar
      mm, memory-failure: fix typo in me_pagecache_dirty() · 549543df
      Zhi Yong Wu authored
      
      
      [akpm@linux-foundation.org: s/cache/pagecache/]
      Signed-off-by: default avatarZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      549543df
    • Kirill A. Shutemov's avatar
      mm: create a separate slab for page->ptl allocation · b35f1819
      Kirill A. Shutemov authored
      
      
      If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64
      is 72 bytes.  For page->ptl they will be allocated from kmalloc-96 slab,
      so we loose 24 on each.  An average system can easily allocate few tens
      thousands of page->ptl and overhead is significant.
      
      Let's create a separate slab for page->ptl allocation to solve this.
      
      To make sure that it really works this time, some numbers from my test
      machine (just booted, no load):
      
      Before:
        # grep '^\(kmalloc-96\|page->ptl\)' /proc/slabinfo
        kmalloc-96         31987  32190    128   30    1 : tunables  120   60    8 : slabdata   1073   1073     92
      After:
        # grep '^\(kmalloc-96\|page->ptl\)' /proc/slabinfo
        page->ptl          27516  28143     72   53    1 : tunables  120   60    8 : slabdata    531    531      9
        kmalloc-96          3853   5280    128   30    1 : tunables  120   60    8 : slabdata    176    176      0
      
      Note that the patch is useful not only for debug case, but also for
      PREEMPT_RT, where spinlock_t is always bloated.
      Signed-off-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>
      b35f1819
    • Yasuaki Ishimatsu's avatar
      mm: get rid of unnecessary pageblock scanning in setup_zone_migrate_reserve · 943dca1a
      Yasuaki Ishimatsu authored
      Yasuaki Ishimatsu reported memory hot-add spent more than 5 _hours_ on
      9TB memory machine since onlining memory sections is too slow.  And we
      found out setup_zone_migrate_reserve spent >90% of the time.
      
      The problem is, setup_zone_migrate_reserve scans all pageblocks
      unconditionally, but it is only necessary if the number of reserved
      block was reduced (i.e.  memory hot remove).
      
      Moreover, maximum MIGRATE_RESERVE per zone is currently 2.  It means
      that the number of reserved pageblocks is almost always unchanged.
      
      This patch adds zone->nr_migrate_reserve_block to maintain the number of
      MIGRATE_RESERVE pageblocks and it reduces the overhead of
      setup_zone_migrate_reserve dramatically.  The following table shows time
      of onlining a memory section.
      
        Amount of memory     | 128GB | 192GB | 256GB|
        ---------------------------------------------
        linux-3.12           |  23.9 |  31.4 | 44.5 |
        This patch           |   8.3 |   8.3 |  8.6 |
        Mel's proposal patch |  10.9 |  19.2 | 31.3 |
        ---------------------------------------------
                                         (millisecond)
      
        128GB : 4 nodes and each node has 32GB of memory
        192GB : 6 nodes and each node has 32GB of memory
        256GB : 8 nodes and each node has 32GB of memory
      
        (*1) Mel proposed his idea by the following threads.
             https://lkml.org/lkml/2013/10/30/272
      
      
      
      [akpm@linux-foundation.org: tweak comment]
      Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: default avatarYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Reported-by: default avatarYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Tested-by: default avatarYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      943dca1a
    • Rik van Riel's avatar
      /proc/meminfo: provide estimated available memory · 34e431b0
      Rik van Riel authored
      
      
      Many load balancing and workload placing programs check /proc/meminfo to
      estimate how much free memory is available.  They generally do this by
      adding up "free" and "cached", which was fine ten years ago, but is
      pretty much guaranteed to be wrong today.
      
      It is wrong because Cached includes memory that is not freeable as page
      cache, for example shared memory segments, tmpfs, and ramfs, and it does
      not include reclaimable slab memory, which can take up a large fraction
      of system memory on mostly idle systems with lots of files.
      
      Currently, the amount of memory that is available for a new workload,
      without pushing the system into swap, can be estimated from MemFree,
      Active(file), Inactive(file), and SReclaimable, as well as the "low"
      watermarks from /proc/zoneinfo.
      
      However, this may change in the future, and user space really should not
      be expected to know kernel internals to come up with an estimate for the
      amount of free memory.
      
      It is more convenient to provide such an estimate in /proc/meminfo.  If
      things change in the future, we only have to change it in one place.
      Signed-off-by: default avatarRik van Riel <riel@redhat.com>
      Reported-by: default avatarErik Mouw <erik.mouw_2@nxp.com>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      34e431b0
    • Oleg Nesterov's avatar
      mm: thp: turn compound_head() into BUG_ON(!PageTail) in get_huge_page_tail() · 5eaf1a9e
      Oleg Nesterov authored
      
      
      get_huge_page_tail()->compound_head() looks confusing.  Every caller
      must check PageTail(page), otherwise atomic_inc(&page->_mapcount) is
      simply wrong if this page is compound-trans-head.
      Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Dave Jones <davej@redhat.com>
      Cc: Darren Hart <dvhart@linux.intel.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mel Gorman <mgorman@suse.de>
      Acked-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5eaf1a9e
    • Oleg Nesterov's avatar
      mm: thp: __get_page_tail_foll() can use get_huge_page_tail() · c728852f
      Oleg Nesterov authored
      
      
      Cleanup. Change __get_page_tail_foll() to use get_huge_page_tail()
      to avoid the code duplication.
      Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Dave Jones <davej@redhat.com>
      Cc: Darren Hart <dvhart@linux.intel.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mel Gorman <mgorman@suse.de>
      Acked-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c728852f
    • Andrea Arcangeli's avatar
      mm/hugetlb.c: defer PageHeadHuge() symbol export · 9b7ac260
      Andrea Arcangeli authored
      
      
      No actual need of it. So keep it internal.
      Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Cc: Khalid Aziz <khalid.aziz@oracle.com>
      Cc: Pravin Shelar <pshelar@nicira.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Ben Hutchings <bhutchings@solarflare.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Johannes Weiner <jweiner@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9b7ac260
    • Andrew Morton's avatar
      mm/swap.c: reorganize put_compound_page() · 26296ad2
      Andrew Morton authored
      
      
      Tweak it so save a tab stop, make code layout slightly less nutty.
      Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Cc: Khalid Aziz <khalid.aziz@oracle.com>
      Cc: Pravin Shelar <pshelar@nicira.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Ben Hutchings <bhutchings@solarflare.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Johannes Weiner <jweiner@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      26296ad2
    • Andrew Morton's avatar
      mm/hugetlb.c: simplify PageHeadHuge() and PageHuge() · 758f66a2
      Andrew Morton authored
      
      Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Cc: Khalid Aziz <khalid.aziz@oracle.com>
      Cc: Pravin Shelar <pshelar@nicira.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Ben Hutchings <bhutchings@solarflare.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Johannes Weiner <jweiner@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      758f66a2
    • Andrea Arcangeli's avatar
      mm: hugetlbfs: use __compound_tail_refcounted in __get_page_tail too · 3bfcd13e
      Andrea Arcangeli authored
      
      
      Also remove hugetlb.h which isn't needed anymore as PageHeadHuge is
      handled in mm.h.
      Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Cc: Khalid Aziz <khalid.aziz@oracle.com>
      Cc: Pravin Shelar <pshelar@nicira.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Ben Hutchings <bhutchings@solarflare.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Johannes Weiner <jweiner@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3bfcd13e
    • Andrea Arcangeli's avatar
      mm: tail page refcounting optimization for slab and hugetlbfs · 44518d2b
      Andrea Arcangeli authored
      
      
      This skips the _mapcount mangling for slab and hugetlbfs pages.
      
      The main trouble in doing this is to guarantee that PageSlab and
      PageHeadHuge remains constant for all get_page/put_page run on the tail
      of slab or hugetlbfs compound pages.  Otherwise if they're set during
      get_page but not set during put_page, the _mapcount of the tail page
      would underflow.
      
      PageHeadHuge will remain true until the compound page is released and
      enters the buddy allocator so it won't risk to change even if the tail
      page is the last reference left on the page.
      
      PG_slab instead is cleared before the slab frees the head page with
      put_page, so if the tail pin is released after the slab freed the page,
      we would have a problem.  But in the slab case the tail pin cannot be
      the last reference left on the page.  This is because the slab code is
      free to reuse the compound page after a kfree/kmem_cache_free without
      having to check if there's any tail pin left.  In turn all tail pins
      must be always released while the head is still pinned by the slab code
      and so we know PG_slab will be still set too.
      Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Reviewed-by: default avatarKhalid Aziz <khalid.aziz@oracle.com>
      Cc: Pravin Shelar <pshelar@nicira.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Ben Hutchings <bhutchings@solarflare.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Johannes Weiner <jweiner@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      44518d2b
    • Andrea Arcangeli's avatar
      mm: thp: optimize compound_trans_huge · ca641514
      Andrea Arcangeli authored
      
      
      Currently we don't clobber page_tail->first_page during split_huge_page,
      so compound_trans_head can be set to compound_head without adverse
      effects, and this mostly optimizes away a smp_rmb.
      
      It looks worthwhile to keep around the implementation that doesn't relay
      on page_tail->first_page not to be clobbered, because it would be
      necessary if we'll decide to enforce page->private to zero at all times
      whenever PG_private is not set, also for anonymous pages.  For anonymous
      pages enforcing such an invariant doesn't matter as anonymous pages
      don't use page->private so we can get away with this microoptimization.
      Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Cc: Khalid Aziz <khalid.aziz@oracle.com>
      Cc: Pravin Shelar <pshelar@nicira.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Ben Hutchings <bhutchings@solarflare.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Johannes Weiner <jweiner@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ca641514
    • Andrea Arcangeli's avatar
      mm: hugetlbfs: move the put/get_page slab and hugetlbfs optimization in a faster path · ebf360f9
      Andrea Arcangeli authored
      
      
      We don't actually need a reference on the head page in the slab and
      hugetlbfs paths, as long as we add a smp_rmb() which should be faster
      than get_page_unless_zero.
      
      [akpm@linux-foundation.org: fix typo in comment]
      Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Cc: Khalid Aziz <khalid.aziz@oracle.com>
      Cc: Pravin Shelar <pshelar@nicira.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Ben Hutchings <bhutchings@solarflare.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Johannes Weiner <jweiner@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ebf360f9
    • Andrea Arcangeli's avatar
      mm: hugetlb: use get_page_foll() in follow_hugetlb_page() · a0368d4e
      Andrea Arcangeli authored
      
      
      get_page_foll() is more optimal and is always safe to use under the PT
      lock.  More so for hugetlbfs as there's no risk of race conditions with
      split_huge_page regardless of the PT lock.
      Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Tested-by: default avatarKhalid Aziz <khalid.aziz@oracle.com>
      Cc: Pravin Shelar <pshelar@nicira.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Ben Hutchings <bhutchings@solarflare.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Johannes Weiner <jweiner@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a0368d4e