16 Dec, 2009

40 commits

  • Just simplify the code when `mlocked' is true.

    Signed-off-by: Huang Shijie
    Reviewed-by: KOSAKI Motohiro
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Huang Shijie
     
  • Fix the comment for try_to_unmap_anon() with the new arguments.

    Signed-off-by: Huang Shijie
    Acked-by: Hugh Dickins
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Huang Shijie
     
  • Commit 543ade1fc9 ("Streamline generic_file_* interfaces and filemap
    cleanups") removed generic_file_write() in filemap. Change the comment in
    vmscan pageout() to __generic_file_aio_write().

    Signed-off-by: Vincent Li
    Cc: Christoph Hellwig
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Vincent Li
     
  • Seems that page_io.c doesn't really need to know that page_private(page)
    is the swp_entry 'val'. Rework map_swap_page() to do what its name says
    and map a page to a page offset in the swap space.

    The only other caller of map_swap_page() is internal to mm/swapfile.c and
    it does want to map a swap entry to the 'sector'. So rename
    map_swap_page() to map_swap_entry(), make it 'static' and and implement
    map_swap_page() as a wrapper around that.

    Signed-off-by: Lee Schermerhorn
    Cc: Hugh Dickins
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • Reorder (and comment) the fields of swap_info_struct, to make better
    use of its cachelines: it's good for swap_duplicate() in particular
    if unsigned int max and swap_map are near the start.

    Signed-off-by: Hugh Dickins
    Cc: KAMEZAWA Hiroyuki
    Cc: Rik van Riel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     
  • While we're fiddling with the swap_map values, let's assign a particular
    value to shmem/tmpfs swap pages: their swap counts are never incremented,
    and it helps swapoff's try_to_unuse() a little if it can immediately
    distinguish those pages from process pages.

    Since we've no use for SWAP_MAP_BAD | COUNT_CONTINUED,
    we might as well use that 0xbf value for SWAP_MAP_SHMEM.

    Signed-off-by: Hugh Dickins
    Reviewed-by: KAMEZAWA Hiroyuki
    Cc: Rik van Riel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     
  • Swap is duplicated (reference count incremented by one) whenever the same
    swap page is inserted into another mm (when forking finds a swap entry in
    place of a pte, or when reclaim unmaps a pte to insert the swap entry).

    swap_info_struct's vmalloc'ed swap_map is the array of these reference
    counts: but what happens when the unsigned short (or unsigned char since
    the preceding patch) is full? (and its high bit is kept for a cache flag)

    We then lose track of it, never freeing, leaving it in use until swapoff:
    at which point we _hope_ that a single pass will have found all instances,
    assume there are no more, and will lose user data if we're wrong.

    Swapping of KSM pages has not yet been enabled; but it is implemented,
    and makes it very easy for a user to overflow the maximum swap count:
    possible with ordinary process pages, but unlikely, even when pid_max
    has been raised from PID_MAX_DEFAULT.

    This patch implements swap count continuations: when the count overflows,
    a continuation page is allocated and linked to the original vmalloc'ed
    map page, and this used to hold the continuation counts for that entry
    and its neighbours. These continuation pages are seldom referenced:
    the common paths all work on the original swap_map, only referring to
    a continuation page when the low "digit" of a count is incremented or
    decremented through SWAP_MAP_MAX.

    Signed-off-by: Hugh Dickins
    Cc: KAMEZAWA Hiroyuki
    Cc: Rik van Riel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     
  • Halve the vmalloc'ed swap_map array from unsigned shorts to unsigned
    chars: it's still very unusual to reach a swap count of 126, and the
    next patch allows it to be extended indefinitely.

    Signed-off-by: Hugh Dickins
    Reviewed-by: KAMEZAWA Hiroyuki
    Cc: Rik van Riel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     
  • Though swap_count() is useful, I'm finding that swap_has_cache() and
    encode_swapmap() obscure what happens in the swap_map entry, just at
    those points where I need to understand it. Remove them, and pass
    more usable "usage" values to scan_swap_map(), swap_entry_free() and
    __swap_duplicate(), instead of the SWAP_MAP and SWAP_CACHE enum.

    Signed-off-by: Hugh Dickins
    Reviewed-by: KAMEZAWA Hiroyuki
    Cc: Rik van Riel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     
  • Move CONFIG_HIBERNATION's swapdev_block() into the main CONFIG_HIBERNATION
    block, remove extraneous whitespace and return, fix typo in a comment.

    Signed-off-by: Hugh Dickins
    Reviewed-by: KAMEZAWA Hiroyuki
    Cc: Rik van Riel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     
  • Make better use of the space by folding first swap_extent into its
    swap_info_struct, instead of just the list_head: swap partitions need
    only that one, and for others it's used as a circular list anyway.

    [jirislaby@gmail.com: fix crash on double swapon]
    Signed-off-by: Hugh Dickins
    Cc: KAMEZAWA Hiroyuki
    Cc: Rik van Riel
    Signed-off-by: Jiri Slaby
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     
  • The swap_info_struct is only 76 or 104 bytes, but it does seem wrong
    to reserve an array of about 30 of them in bss, when most people will
    want only one. Change swap_info[] to an array of pointers.

    That does need a "type" field in the structure: pack it as a char with
    next type and short prio (aha, char is unsigned by default on PowerPC).
    Use the (admittedly peculiar) name "type" throughout for this index.

    /proc/swaps does not take swap_lock: I wouldn't want it to, but do take
    care with barriers when adding a new item to the array (never removed).

    Signed-off-by: Hugh Dickins
    Reviewed-by: KAMEZAWA Hiroyuki
    Acked-by: Rik van Riel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     
  • The swap_info_struct is mostly private to mm/swapfile.c, with only
    one other in-tree user: get_swap_bio(). Adjust its interface to
    map_swap_page(), so that we can then remove get_swap_info_struct().

    But there is a popular user out-of-tree, TuxOnIce: so leave the
    declaration of swap_info_struct in linux/swap.h.

    Signed-off-by: Hugh Dickins
    Cc: Nigel Cunningham
    Cc: KAMEZAWA Hiroyuki
    Reviewed-by: Rik van Riel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     
  • - avoid wasting more precious resources (DMA or DMA32 pools), when
    being called through vmalloc_32{,_user}()
    - explicitly allow using high memory here even if the outer allocation
    request doesn't allow it

    Signed-off-by: Jan Beulich
    Acked-by: Hugh Dickins
    Cc: Nick Piggin
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jan Beulich
     
  • Objects passed to NODEMASK_ALLOC() are relatively small in size and are
    backed by slab caches that are not of large order, traditionally never
    greater than PAGE_ALLOC_COSTLY_ORDER.

    Thus, using GFP_KERNEL for these allocations on large machines when
    CONFIG_NODES_SHIFT > 8 will cause the page allocator to loop endlessly in
    the allocation attempt, each time invoking both direct reclaim or the oom
    killer.

    This is of particular interest when using NODEMASK_ALLOC() from a
    mempolicy context (either directly in mm/mempolicy.c or the mempolicy
    constrained hugetlb allocations) since the oom killer always kills current
    when allocations are constrained by mempolicies. So for all present use
    cases in the kernel, current would end up being oom killed when direct
    reclaim fails. That would allow the NODEMASK_ALLOC() to succeed but
    current would have sacrificed itself upon returning.

    This patch adds gfp flags to NODEMASK_ALLOC() to pass to kmalloc() on
    CONFIG_NODES_SHIFT > 8; this parameter is a nop on other configurations.
    All current use cases either directly from hugetlb code or indirectly via
    NODEMASK_SCRATCH() union __GFP_NORETRY to avoid direct reclaim and the oom
    killer when the slab allocator needs to allocate additional pages.

    The side-effect of this change is that all current use cases of either
    NODEMASK_ALLOC() or NODEMASK_SCRATCH() need appropriate -ENOMEM handling
    when the allocation fails (never for CONFIG_NODES_SHIFT
    Acked-by: KAMEZAWA Hiroyuki
    Cc: Lee Schermerhorn
    Cc: Mel Gorman
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Cc: Andi Kleen
    Cc: David Rientjes
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Rientjes
     
  • Offload the registration and unregistration of per node hstate sysfs
    attributes to a worker thread rather than attempt the
    allocation/attachment or detachment/freeing of the attributes in the
    context of the memory hotplug handler.

    I don't know that this is absolutely required, but the registration can
    sleep in allocations and other mem hot plug handlers do it this way. If
    it turns out this is NOT required, we can drop this patch.

    N.B., Only tested build, boot, libhugetlbfs regression.
    i.e., no memory hotplug testing.

    Signed-off-by: Lee Schermerhorn
    Reviewed-by: Andi Kleen
    Cc: KAMEZAWA Hiroyuki
    Cc: Lee Schermerhorn
    Cc: Mel Gorman
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Cc: David Rientjes
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • Register per node hstate attributes only for nodes with memory. As
    suggested by David Rientjes.

    With Memory Hotplug, memory can be added to a memoryless node and a node
    with memory can become memoryless. Therefore, add a memory on/off-line
    notifier callback to [un]register a node's attributes on transition
    to/from memoryless state.

    N.B., Only tested build, boot, libhugetlbfs regression.
    i.e., no memory hotplug testing.

    Signed-off-by: Lee Schermerhorn
    Reviewed-by: Andi Kleen
    Acked-by: David Rientjes
    Cc: KAMEZAWA Hiroyuki
    Cc: Lee Schermerhorn
    Cc: Mel Gorman
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • When memory is hot-removed, its node must be cleared in N_HIGH_MEMORY if
    there are no present pages left.

    In such a situation, kswapd must also be stopped since it has nothing left
    to do.

    Signed-off-by: David Rientjes
    Signed-off-by: Lee Schermerhorn
    Cc: Christoph Lameter
    Cc: Yasunori Goto
    Cc: Mel Gorman
    Cc: Rafael J. Wysocki
    Cc: Rik van Riel
    Cc: KAMEZAWA Hiroyuki
    Cc: Lee Schermerhorn
    Cc: Mel Gorman
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Cc: Andi Kleen
    Cc: David Rientjes
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Rientjes
     
  • Register per node hstate sysfs attributes only for nodes with memory.
    Global replacement of 'all online nodes" with "all nodes with memory" in
    mm/hugetlb.c. Suggested by David Rientjes.

    A subsequent patch will handle adding/removing of per node hstate sysfs
    attributes when nodes transition to/from memoryless state via memory
    hotplug.

    NOTE: this patch has not been tested with memoryless nodes.

    Signed-off-by: Lee Schermerhorn
    Reviewed-by: Andi Kleen
    Cc: KAMEZAWA Hiroyuki
    Cc: Mel Gorman
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Acked-by: David Rientjes
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • Update the kernel huge tlb documentation to describe the numa memory
    policy based huge page management. Additionaly, the patch includes a fair
    amount of rework to improve consistency, eliminate duplication and set the
    context for documenting the memory policy interaction.

    Signed-off-by: Lee Schermerhorn
    Acked-by: David Rientjes
    Acked-by: Mel Gorman
    Reviewed-by: Andi Kleen
    Cc: KAMEZAWA Hiroyuki
    Cc: Lee Schermerhorn
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • Add the per huge page size control/query attributes to the per node
    sysdevs:

    /sys/devices/system/node/node/hugepages/hugepages-/
    nr_hugepages - r/w
    free_huge_pages - r/o
    surplus_huge_pages - r/o

    The patch attempts to re-use/share as much of the existing global hstate
    attribute initialization and handling, and the "nodes_allowed" constraint
    processing as possible.

    Calling set_max_huge_pages() with no node indicates a change to global
    hstate parameters. In this case, any non-default task mempolicy will be
    used to generate the nodes_allowed mask. A valid node id indicates an
    update to that node's hstate parameters, and the count argument specifies
    the target count for the specified node. From this info, we compute the
    target global count for the hstate and construct a nodes_allowed node mask
    contain only the specified node.

    Setting the node specific nr_hugepages via the per node attribute
    effectively ignores any task mempolicy or cpuset constraints.

    With this patch:

    (me):ls /sys/devices/system/node/node0/hugepages/hugepages-2048kB
    ./ ../ free_hugepages nr_hugepages surplus_hugepages

    Starting from:
    Node 0 HugePages_Total: 0
    Node 0 HugePages_Free: 0
    Node 0 HugePages_Surp: 0
    Node 1 HugePages_Total: 0
    Node 1 HugePages_Free: 0
    Node 1 HugePages_Surp: 0
    Node 2 HugePages_Total: 0
    Node 2 HugePages_Free: 0
    Node 2 HugePages_Surp: 0
    Node 3 HugePages_Total: 0
    Node 3 HugePages_Free: 0
    Node 3 HugePages_Surp: 0
    vm.nr_hugepages = 0

    Allocate 16 persistent huge pages on node 2:
    (me):echo 16 >/sys/devices/system/node/node2/hugepages/hugepages-2048kB/nr_hugepages

    [Note that this is equivalent to:
    numactl -m 2 hugeadmin --pool-pages-min 2M:+16
    ]

    Yields:
    Node 0 HugePages_Total: 0
    Node 0 HugePages_Free: 0
    Node 0 HugePages_Surp: 0
    Node 1 HugePages_Total: 0
    Node 1 HugePages_Free: 0
    Node 1 HugePages_Surp: 0
    Node 2 HugePages_Total: 16
    Node 2 HugePages_Free: 16
    Node 2 HugePages_Surp: 0
    Node 3 HugePages_Total: 0
    Node 3 HugePages_Free: 0
    Node 3 HugePages_Surp: 0
    vm.nr_hugepages = 16

    Global controls work as expected--reduce pool to 8 persistent huge pages:
    (me):echo 8 >/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages

    Node 0 HugePages_Total: 0
    Node 0 HugePages_Free: 0
    Node 0 HugePages_Surp: 0
    Node 1 HugePages_Total: 0
    Node 1 HugePages_Free: 0
    Node 1 HugePages_Surp: 0
    Node 2 HugePages_Total: 8
    Node 2 HugePages_Free: 8
    Node 2 HugePages_Surp: 0
    Node 3 HugePages_Total: 0
    Node 3 HugePages_Free: 0
    Node 3 HugePages_Surp: 0

    Signed-off-by: Lee Schermerhorn
    Acked-by: Mel Gorman
    Reviewed-by: Andi Kleen
    Cc: KAMEZAWA Hiroyuki
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Cc: David Rientjes
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • Move definition of NUMA_NO_NODE from ia64 and x86_64 arch specific headers
    to generic header 'linux/numa.h' for use in generic code. NUMA_NO_NODE
    replaces bare '-1' where it's used in this series to indicate "no node id
    specified". Ultimately, it can be used to replace the -1 elsewhere where
    it is used similarly.

    Signed-off-by: Lee Schermerhorn
    Acked-by: David Rientjes
    Acked-by: Mel Gorman
    Reviewed-by: Andi Kleen
    Cc: KAMEZAWA Hiroyuki
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • This patch derives a "nodes_allowed" node mask from the numa mempolicy of
    the task modifying the number of persistent huge pages to control the
    allocation, freeing and adjusting of surplus huge pages when the pool page
    count is modified via the new sysctl or sysfs attribute
    "nr_hugepages_mempolicy". The nodes_allowed mask is derived as follows:

    * For "default" [NULL] task mempolicy, a NULL nodemask_t pointer
    is produced. This will cause the hugetlb subsystem to use
    node_online_map as the "nodes_allowed". This preserves the
    behavior before this patch.
    * For "preferred" mempolicy, including explicit local allocation,
    a nodemask with the single preferred node will be produced.
    "local" policy will NOT track any internode migrations of the
    task adjusting nr_hugepages.
    * For "bind" and "interleave" policy, the mempolicy's nodemask
    will be used.
    * Other than to inform the construction of the nodes_allowed node
    mask, the actual mempolicy mode is ignored. That is, all modes
    behave like interleave over the resulting nodes_allowed mask
    with no "fallback".

    See the updated documentation [next patch] for more information
    about the implications of this patch.

    Examples:

    Starting with:

    Node 0 HugePages_Total: 0
    Node 1 HugePages_Total: 0
    Node 2 HugePages_Total: 0
    Node 3 HugePages_Total: 0

    Default behavior [with or without this patch] balances persistent
    hugepage allocation across nodes [with sufficient contiguous memory]:

    sysctl vm.nr_hugepages[_mempolicy]=32

    yields:

    Node 0 HugePages_Total: 8
    Node 1 HugePages_Total: 8
    Node 2 HugePages_Total: 8
    Node 3 HugePages_Total: 8

    Of course, we only have nr_hugepages_mempolicy with the patch,
    but with default mempolicy, nr_hugepages_mempolicy behaves the
    same as nr_hugepages.

    Applying mempolicy--e.g., with numactl [using '-m' a.k.a.
    '--membind' because it allows multiple nodes to be specified
    and it's easy to type]--we can allocate huge pages on
    individual nodes or sets of nodes. So, starting from the
    condition above, with 8 huge pages per node, add 8 more to
    node 2 using:

    numactl -m 2 sysctl vm.nr_hugepages_mempolicy=40

    This yields:

    Node 0 HugePages_Total: 8
    Node 1 HugePages_Total: 8
    Node 2 HugePages_Total: 16
    Node 3 HugePages_Total: 8

    The incremental 8 huge pages were restricted to node 2 by the
    specified mempolicy.

    Similarly, we can use mempolicy to free persistent huge pages
    from specified nodes:

    numactl -m 0,1 sysctl vm.nr_hugepages_mempolicy=32

    yields:

    Node 0 HugePages_Total: 4
    Node 1 HugePages_Total: 4
    Node 2 HugePages_Total: 16
    Node 3 HugePages_Total: 8

    The 8 huge pages freed were balanced over nodes 0 and 1.

    [rientjes@google.com: accomodate reworked NODEMASK_ALLOC]
    Signed-off-by: David Rientjes
    Signed-off-by: Lee Schermerhorn
    Acked-by: Mel Gorman
    Reviewed-by: Andi Kleen
    Cc: KAMEZAWA Hiroyuki
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • Factor init_nodemask_of_node() out of the nodemask_of_node() macro.

    This will be used to populate the huge pages "nodes_allowed" nodemask for
    a single node when basing nodes_allowed on a preferred/local mempolicy or
    when a persistent huge page pool page count is modified via a per node
    sysfs attribute.

    Signed-off-by: Lee Schermerhorn
    Acked-by: Mel Gorman
    Reviewed-by: Andi Kleen
    Cc: KAMEZAWA Hiroyuki
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Acked-by: David Rientjes
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • In preparation for constraining huge page allocation and freeing by the
    controlling task's numa mempolicy, add a "nodes_allowed" nodemask pointer
    to the allocate, free and surplus adjustment functions. For now, pass
    NULL to indicate default behavior--i.e., use node_online_map. A
    subsqeuent patch will derive a non-default mask from the controlling
    task's numa mempolicy.

    Note that this method of updating the global hstate nr_hugepages under the
    constraint of a nodemask simplifies keeping the global state
    consistent--especially the number of persistent and surplus pages relative
    to reservations and overcommit limits. There are undoubtedly other ways
    to do this, but this works for both interfaces: mempolicy and per node
    attributes.

    [rientjes@google.com: fix HIGHMEM compile error]
    Signed-off-by: Lee Schermerhorn
    Reviewed-by: Mel Gorman
    Acked-by: David Rientjes
    Reviewed-by: Andi Kleen
    Cc: KAMEZAWA Hiroyuki
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Cc: Andi Kleen
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: David Rientjes
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • Modify the hstate_next_node* functions to allow them to be called to
    obtain the "start_nid". Then, whereas prior to this patch we
    unconditionally called hstate_next_node_to_{alloc|free}(), whether or not
    we successfully allocated/freed a huge page on the node, now we only call
    these functions on failure to alloc/free to advance to next allowed node.

    Factor out the next_node_allowed() function to handle wrap at end of
    node_online_map. In this version, the allowed nodes include all of the
    online nodes.

    Signed-off-by: Lee Schermerhorn
    Reviewed-by: Mel Gorman
    Acked-by: David Rientjes
    Reviewed-by: Andi Kleen
    Cc: KAMEZAWA Hiroyuki
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Cc: Andi Kleen
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • This is a series of patches to provide control over the location of the
    allocation and freeing of persistent huge pages on a NUMA platform.
    Please consider for merging into mmotm.

    This series uses two mechanisms to constrain the nodes from which
    persistent huge pages are allocated: 1) the task NUMA mempolicy of the
    task modifying a new sysctl "nr_hugepages_mempolicy", based on a
    suggestion by Mel Gorman; and 2) a subset of the hugepages hstate sysfs
    attributes have been added [in V4] to each node system device under:

    /sys/devices/node/node[0-9]*/hugepages

    The per node attibutes allow direct assignment of a huge page count on a
    specific node, regardless of the task's mempolicy or cpuset constraints.

    This patch:

    NODEMASK_ALLOC(x, m) assumes x is a type of struct, which is unnecessary.
    It's perfectly reasonable to use this macro to allocate a nodemask_t,
    which is anonymous, either dynamically or on the stack depending on
    NODES_SHIFT.

    Signed-off-by: David Rientjes
    Signed-off-by: Lee Schermerhorn
    Acked-by: KAMEZAWA Hiroyuki
    Cc: Mel Gorman
    Cc: Randy Dunlap
    Cc: Nishanth Aravamudan
    Cc: Andi Kleen
    Cc: David Rientjes
    Cc: Adam Litke
    Cc: Andy Whitcroft
    Cc: Eric Whitney
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Rientjes
     
  • Christoph pointed out inc_zone_page_state(NR_ISOLATED) should be placed
    in right after isolate_page().

    This patch does it.

    Reviewed-by: Christoph Lameter
    Signed-off-by: KOSAKI Motohiro
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    KOSAKI Motohiro
     
  • Signed-off-by: Wu Fengguang
    Cc: Andi Kleen
    Cc: Avi Kivity
    Cc: Greg Kroah-Hartman
    Cc: Johannes Berg
    Cc: Marcelo Tosatti
    Cc: Mark Brown
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Wu Fengguang
     
  • Also rename "len" to "sz". No behavior change.

    Signed-off-by: Wu Fengguang
    Cc: Andi Kleen
    Cc: Avi Kivity
    Cc: Greg Kroah-Hartman
    Cc: Johannes Berg
    Cc: Marcelo Tosatti
    Cc: Mark Brown
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Wu Fengguang
     
  • Also convert more size_inside_page() users.

    Signed-off-by: Wu Fengguang
    Cc: Andi Kleen
    Cc: Avi Kivity
    Cc: Greg Kroah-Hartman
    Cc: Johannes Berg
    Cc: Marcelo Tosatti
    Cc: Mark Brown
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Wu Fengguang
     
  • No behaviour change.

    [akpm@linux-foundation.org: cleanuplets]
    [akpm@linux-foundation.org: remove unused `ret']
    Signed-off-by: Wu Fengguang
    Acked-by: Andi Kleen
    Cc: Marcelo Tosatti
    Cc: Greg Kroah-Hartman
    Cc: Mark Brown
    Cc: Johannes Berg
    Cc: Avi Kivity
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Wu Fengguang
     
  • Introduce size_inside_page() to replace duplicate /dev/mem code.

    Also apply it to /dev/kmem, whose alignment logic was buggy.

    Signed-off-by: Wu Fengguang
    Acked-by: Andi Kleen
    Cc: Marcelo Tosatti
    Cc: Greg Kroah-Hartman
    Cc: Mark Brown
    Cc: Johannes Berg
    Cc: Avi Kivity
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Wu Fengguang
     
  • The len test in write_kmem() is always true, so can be reduced.

    Signed-off-by: Wu Fengguang
    Acked-by: Andi Kleen
    Cc: Marcelo Tosatti
    Cc: Greg Kroah-Hartman
    Cc: Mark Brown
    Cc: Johannes Berg
    Cc: Avi Kivity
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Wu Fengguang
     
  • On ia64, the following test program exit abnormally, because glibc thread
    library called abort().

    ========================================================
    (gdb) bt
    #0 0xa000000000010620 in __kernel_syscall_via_break ()
    #1 0x20000000003208e0 in raise () from /lib/libc.so.6.1
    #2 0x2000000000324090 in abort () from /lib/libc.so.6.1
    #3 0x200000000027c3e0 in __deallocate_stack () from /lib/libpthread.so.0
    #4 0x200000000027f7c0 in start_thread () from /lib/libpthread.so.0
    #5 0x200000000047ef60 in __clone2 () from /lib/libc.so.6.1
    ========================================================

    The fact is, glibc call munmap() when thread exitng time for freeing
    stack, and it assume munlock() never fail. However, munmap() often make
    vma splitting and it with many mapcount make -ENOMEM.

    Oh well, that's crazy, because stack unmapping never increase mapcount.
    The maxcount exceeding is only temporary. internal temporary exceeding
    shouldn't make ENOMEM.

    This patch does it.

    test_max_mapcount.c
    ==================================================================
    #include
    #include
    #include
    #include
    #include
    #include

    #define THREAD_NUM 30000
    #define MAL_SIZE (8*1024*1024)

    void *wait_thread(void *args)
    {
    void *addr;

    addr = malloc(MAL_SIZE);
    sleep(10);

    return NULL;
    }

    void *wait_thread2(void *args)
    {
    sleep(60);

    return NULL;
    }

    int main(int argc, char *argv[])
    {
    int i;
    pthread_t thread[THREAD_NUM], th;
    int ret, count = 0;
    pthread_attr_t attr;

    ret = pthread_attr_init(&attr);
    if(ret) {
    perror("pthread_attr_init");
    }

    ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
    if(ret) {
    perror("pthread_attr_setdetachstate");
    }

    for (i = 0; i < THREAD_NUM; i++) {
    ret = pthread_create(&th, &attr, wait_thread, NULL);
    if(ret) {
    fprintf(stderr, "[%d] ", count);
    perror("pthread_create");
    } else {
    printf("[%d] create OK.\n", count);
    }
    count++;

    ret = pthread_create(&thread[i], &attr, wait_thread2, NULL);
    if(ret) {
    fprintf(stderr, "[%d] ", count);
    perror("pthread_create");
    } else {
    printf("[%d] create OK.\n", count);
    }
    count++;
    }

    sleep(3600);
    return 0;
    }
    ==================================================================

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: KOSAKI Motohiro
    Signed-off-by: Hugh Dickins
    Cc: KAMEZAWA Hiroyuki
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    KOSAKI Motohiro
     
  • On a system with large amount of memory (256GB), invoking page-types can
    take quite a long time, which is unreasonable considering the user only
    wants a description of the flags:

    # time ./page-types -d 0x10
    0x0000000000000010 ____D_____________________________ dirty

    real 0m34.285s
    user 0m1.966s
    sys 0m32.313s

    This is because we still walk the entire address range.

    Exiting early seems like a reasonble solution:

    # time ./page-types -d 0x10
    0x0000000000000010 ____D_____________________________ dirty

    real 0m0.007s
    user 0m0.001s
    sys 0m0.005s

    Signed-off-by: Alex Chiang
    Cc: Andi Kleen
    Cc: Haicheng Li
    Acked-by: Wu Fengguang
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alex Chiang
     
  • Align the output when page-type -h is invoked.

    Signed-off-by: Alex Chiang
    Acked-by: Wu Fengguang
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alex Chiang
     
  • Teach page-types to describe page flags directly from the command line.

    Why is this useful? For instance, if you're using memory hotplug and see
    this in /var/log/messages:

    kernel: removing from LRU failed 3836dd0/1/1e00000000000010

    It would be nice to decode those page flags without staring at the source.

    Example usage and output:

    # Documentation/vm/page-types -d 0x10
    0x0000000000000010 ____D_____________________________ dirty

    # Documentation/vm/page-types -d anon
    0x0000000000001000 ____________a_____________________ anonymous

    # Documentation/vm/page-types -d anon,0x10
    0x0000000000001010 ____D_______a_____________________ dirty,anonymous

    [achiang@hp.com: documentation]
    Signed-off-by: Alex Chiang
    Signed-off-by: Wu Fengguang
    Cc: Andi Kleen
    Cc: Haicheng Li
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alex Chiang
     
  • If not signed, testing of the read() return value in this function
    will not work.

    Signed-off-by: Roel Kluin
    Cc: Wu Fengguang
    Cc: Randy Dunlap
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Roel Kluin
     
  • Signed-off-by: Tommi Rantala
    Cc: Randy Dunlap
    Cc: Wu Fengguang
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Tommi Rantala