1. 28 Apr, 2008 40 commits
    • Lee Schermerhorn's avatar
      mempolicy: rework mempolicy Reference Counting [yet again] · 52cd3b07
      Lee Schermerhorn authored
      
      
      After further discussion with Christoph Lameter, it has become clear that my
      earlier attempts to clean up the mempolicy reference counting were a bit of
      overkill in some areas, resulting in superflous ref/unref in what are usually
      fast paths.  In other areas, further inspection reveals that I botched the
      unref for interleave policies.
      
      A separate patch, suitable for upstream/stable trees, fixes up the known
      errors in the previous attempt to fix reference counting.
      
      This patch reworks the memory policy referencing counting and, one hopes,
      simplifies the code.  Maybe I'll get it right this time.
      
      See the update to the numa_memory_policy.txt document for a discussion of
      memory policy reference counting that motivates this patch.
      
      Summary:
      
      Lookup of mempolicy, based on (vma, address) need only add a reference for
      shared policy, and we need only unref the policy when finished for shared
      policies.  So, this patch backs out all of the unneeded extra reference
      counting added by my previous attempt.  It then unrefs only shared policies
      when we're finished with them, using the mpol_cond_put() [conditional put]
      helper function introduced by this patch.
      
      Note that shmem_swapin() calls read_swap_cache_async() with a dummy vma
      containing just the policy.  read_swap_cache_async() can call alloc_page_vma()
      multiple times, so we can't let alloc_page_vma() unref the shared policy in
      this case.  To avoid this, we make a copy of any non-null shared policy and
      remove the MPOL_F_SHARED flag from the copy.  This copy occurs before reading
      a page [or multiple pages] from swap, so the overhead should not be an issue
      here.
      
      I introduced a new static inline function "mpol_cond_copy()" to copy the
      shared policy to an on-stack policy and remove the flags that would require a
      conditional free.  The current implementation of mpol_cond_copy() assumes that
      the struct mempolicy contains no pointers to dynamically allocated structures
      that must be duplicated or reference counted during copy.
      
      Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
      Cc: Christoph Lameter <clameter@sgi.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Andi Kleen <ak@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      52cd3b07
    • Lee Schermerhorn's avatar
      mempolicy: document {set|get}_policy() vm_ops APIs · a6020ed7
      Lee Schermerhorn authored
      
      
      Document mempolicy return value reference semantics assumed by the rest of the
      mempolicy code for the set_ and get_policy vm_ops in <linux/mm.h>--where the
      prototypes are defined--to inform any future mempolicy vm_op writers what the
      rest of the subsystem expects of them.
      
      Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
      Cc: Christoph Lameter <clameter@sgi.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Andi Kleen <ak@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a6020ed7
    • Lee Schermerhorn's avatar
      mempolicy: mark shared policies for unref · aab0b102
      Lee Schermerhorn authored
      
      
      As part of yet another rework of mempolicy reference counting, we want to be
      able to identify shared policies efficiently, because they have an extra ref
      taken on lookup that needs to be removed when we're finished using the policy.
      
        Note:  the extra ref is required because the policies are
        shared between tasks/processes and can be changed/freed
        by one task while another task is using them--e.g., for
        page allocation.
      
      Building on David Rientjes mempolicy "mode flags" enhancement, this patch
      indicates a "shared" policy by setting a new MPOL_F_SHARED flag in the flags
      member of the struct mempolicy added by David.  MPOL_F_SHARED, and any future
      "internal mode flags" are reserved from bit zero up, as they will never be
      passed in the upper bits of the mode argument of a mempolicy API.
      
      I set the MPOL_F_SHARED flag when the policy is installed in the shared policy
      rb-tree.  Don't need/want to clear the flag when removing from the tree as the
      mempolicy is freed [unref'd] internally to the sp_delete() function.  However,
      a task could hold another reference on this mempolicy from a prior lookup.  We
      need the MPOL_F_SHARED flag to stay put so that any tasks holding a ref will
      unref, eventually freeing, the mempolicy.
      
      A later patch in this series will introduce a function to conditionally unref
      [mpol_free] a policy.  The MPOL_F_SHARED flag is one reason [currently the
      only reason] to unref/free a policy via the conditional free.
      
      Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
      Cc: Christoph Lameter <clameter@sgi.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Andi Kleen <ak@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      aab0b102
    • Lee Schermerhorn's avatar
      mempolicy: rename struct mempolicy 'policy' member to 'mode' · 45c4745a
      Lee Schermerhorn authored
      
      
      The terms 'policy' and 'mode' are both used in various places to describe the
      semantics of the value stored in the 'policy' member of struct mempolicy.
      Furthermore, the term 'policy' is used to refer to that member, to the entire
      struct mempolicy and to the more abstract concept of the tuple consisting of a
      "mode" and an optional node or set of nodes.  Recently, we have added "mode
      flags" that are passed in the upper bits of the 'mode' [or sometimes,
      'policy'] member of the numa APIs.
      
      I'd like to resolve this confusion, which perhaps only exists in my mind, by
      renaming the 'policy' member to 'mode' throughout, and fixing up the
      Documentation.  Man pages will be updated separately.
      
      Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
      Cc: Christoph Lameter <clameter@sgi.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Andi Kleen <ak@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      45c4745a
    • Lee Schermerhorn's avatar
      mempolicy: fixup Fallback for Default Shmem Policy · ae4d8c16
      Lee Schermerhorn authored
      
      
      get_vma_policy() is not handling fallback to task policy correctly when the
      get_policy() vm_op returns NULL.  The NULL overwrites the 'pol' variable that
      was holding the fallback task mempolicy.  So, it was falling back directly to
      system default policy.
      
      Fix get_vma_policy() to use only non-NULL policy returned from the vma
      get_policy op.
      
      shm_get_policy() was falling back to current task's mempolicy if the "backing
      file system" [tmpfs vs hugetlbfs] does not support the get_policy vm_op and
      the vma policy is null.  This is incorrect for show_numa_maps() which is
      likely querying the numa_maps of some task other than current.  Remove this
      fallback.
      
      Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
      Cc: Christoph Lameter <clameter@sgi.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Andi Kleen <ak@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ae4d8c16
    • Lee Schermerhorn's avatar
      mempolicy: write lock mmap_sem while changing task mempolicy · f4e53d91
      Lee Schermerhorn authored
      
      
      A read of /proc/<pid>/numa_maps holds the target task's mmap_sem for read
      while examining each vma's mempolicy.  A vma's mempolicy can fall back to the
      task's policy.  However, the task could be changing it's task policy and free
      the one that the show_numa_maps() is examining.
      
      To prevent this, grab the mmap_sem for write when updating task mempolicy.
      Pointed out to me by Christoph Lameter and extracted and reworked from
      Christoph's alternative mempol reference counting patch.
      
      This is analogous to the way that do_mbind() and do_get_mempolicy() prevent
      races between task's sharing an mm_struct [a.k.a.  threads] setting and
      querying a mempolicy for a particular address.
      
      Note: this is necessary, but not sufficient, to allow us to stop taking an
      extra reference on "other task's mempolicy" in get_vma_policy.  Subsequent
      patches will complete this update, allowing us to simplify the tests for
      whether we need to unref a mempolicy at various points in the code.
      
      Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
      Cc: Christoph Lameter <clameter@sgi.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Andi Kleen <ak@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f4e53d91
    • Lee Schermerhorn's avatar
      mempolicy: rename mpol_copy to mpol_dup · 846a16bf
      Lee Schermerhorn authored
      
      
      This patch renames mpol_copy() to mpol_dup() because, well, that's what it
      does.  Like, e.g., strdup() for strings, mpol_dup() takes a pointer to an
      existing mempolicy, allocates a new one and copies the contents.
      
      In a later patch, I want to use the name mpol_copy() to copy the contents from
      one mempolicy to another like, e.g., strcpy() does for strings.
      
      Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
      Cc: Christoph Lameter <clameter@sgi.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Andi Kleen <ak@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      846a16bf
    • Lee Schermerhorn's avatar
      mempolicy: rename mpol_free to mpol_put · f0be3d32
      Lee Schermerhorn authored
      
      
      This is a change that was requested some time ago by Mel Gorman.  Makes sense
      to me, so here it is.
      
      Note: I retain the name "mpol_free_shared_policy()" because it actually does
      free the shared_policy, which is NOT a reference counted object.  However, ...
      
      The mempolicy object[s] referenced by the shared_policy are reference counted,
      so mpol_put() is used to release the reference held by the shared_policy.  The
      mempolicy might not be freed at this time, because some task attached to the
      shared object associated with the shared policy may be in the process of
      allocating a page based on the mempolicy.  In that case, the task performing
      the allocation will hold a reference on the mempolicy, obtained via
      mpol_shared_policy_lookup().  The mempolicy will be freed when all tasks
      holding such a reference have called mpol_put() for the mempolicy.
      
      Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
      Cc: Christoph Lameter <clameter@sgi.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Andi Kleen <ak@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f0be3d32
    • Adam Litke's avatar
      Subject: [PATCH] hugetlb: vmstat events for huge page allocations · 3b116300
      Adam Litke authored
      
      
      Allocating huge pages directly from the buddy allocator is not guaranteed to
      succeed.  Success depends on several factors (such as the amount of physical
      memory available and the level of fragmentation).  With the addition of
      dynamic hugetlb pool resizing, allocations can occur much more frequently.
      For these reasons it is desirable to keep track of huge page allocation
      successes and failures.
      
      Add two new vmstat entries to track huge page allocations that succeed and
      fail.  The presence of the two entries is contingent upon CONFIG_HUGETLB_PAGE
      being enabled.
      
      [akpm@linux-foundation.org: reduced ifdeffery]
      Signed-off-by: default avatarAdam Litke <agl@us.ibm.com>
      Signed-off-by: default avatarEric Munson <ebmunson@us.ibm.com>
      Tested-by: default avatarMel Gorman <mel@csn.ul.ie>
      Reviewed-by: default avatarAndy Whitcroft <apw@shadowen.org>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3b116300
    • Ken'ichi Ohmichi's avatar
      vmcoreinfo: add page flags values · 122c7a59
      Ken'ichi Ohmichi authored
      Add some values of page flags to the vmcoreinfo data.
      
      The vmcoreinfo data has the minimum debugging information only for dump
      filtering.  makedumpfile (dump filtering command) gets it to distinguish
      unnecessary pages, and makedumpfile creates a small dumpfile.
      
      An old makedumpfile (v1.2.4 or before) had assumed some values of page flags
      internally, and this implementation could not follow the change of these
      values.  For example, Christoph Lameter is changing these values by the
      follwing patch: http://lkml.org/lkml/2008/2/29/463
      
      
      
      So a new makedumpfile (v1.2.5) came to need these values and I created this
      patch to let the kernel output them.
      
      Signed-off-by: default avatarKen'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
      Cc: Christoph Lameter <clameter@sgi.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Acked-by: default avatarVivek Goyal <vgoyal@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      122c7a59
    • Nick Piggin's avatar
      s390: implement pte special bit · a08cb629
      Nick Piggin authored
      
      
      Convert XIP to support non-struct page backed memory, using VM_MIXEDMAP for
      the user mappings.
      
      This requires the get_xip_page API to be changed to an address based one.
      Improve the API layering a little bit too, while we're here.
      
      This is required in order to support XIP filesystems on memory that isn't
      backed with struct page (but memory with struct page is still supported too).
      
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Acked-by: default avatarCarsten Otte <cotte@de.ibm.com>
      Cc: Jared Hulbert <jaredeh@gmail.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a08cb629
    • Nick Piggin's avatar
      xip: support non-struct page backed memory · 70688e4d
      Nick Piggin authored
      
      
      Convert XIP to support non-struct page backed memory, using VM_MIXEDMAP for
      the user mappings.
      
      This requires the get_xip_page API to be changed to an address based one.
      Improve the API layering a little bit too, while we're here.
      
      This is required in order to support XIP filesystems on memory that isn't
      backed with struct page (but memory with struct page is still supported too).
      
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Acked-by: default avatarCarsten Otte <cotte@de.ibm.com>
      Cc: Jared Hulbert <jaredeh@gmail.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      70688e4d
    • Jared Hulbert's avatar
      return pfn from direct_access, for XIP · 30afcb4b
      Jared Hulbert authored
      
      
      Alter the block device ->direct_access() API to work with the new
      get_xip_mem() API (that requires both kaddr and pfn are returned).
      
      Some architectures will not do the right thing in their virt_to_page() for use
      by XIP (to translate from the kernel virtual address returned by
      direct_access(), to a user mappable pfn in XIP's page fault handler.
      
      However, we can't switch it to just return the pfn and not the kaddr, because
      we have no good way to get a kva from a pfn, and XIP requires the kva for its
      read(2) and write(2) handlers.  So we have to return both.
      
      Signed-off-by: default avatarJared Hulbert <jaredeh@gmail.com>
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Cc: Carsten Otte <cotte@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: linux-mm@kvack.org
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      30afcb4b
    • Nick Piggin's avatar
      mm: add vm_insert_mixed · 423bad60
      Nick Piggin authored
      
      
      vm_insert_mixed will insert either a raw pfn or a refcounted struct page into
      the page tables, depending on whether vm_normal_page() will return the page or
      not.  With the introduction of the new pte bit, this is now a too tricky for
      drivers to be doing themselves.
      
      filemap_xip uses this in a subsequent patch.
      
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Cc: Jared Hulbert <jaredeh@gmail.com>
      Cc: Carsten Otte <cotte@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      423bad60
    • Nick Piggin's avatar
      mm: introduce pte_special pte bit · 7e675137
      Nick Piggin authored
      
      
      s390 for one, cannot implement VM_MIXEDMAP with pfn_valid, due to their memory
      model (which is more dynamic than most).  Instead, they had proposed to
      implement it with an additional path through vm_normal_page(), using a bit in
      the pte to determine whether or not the page should be refcounted:
      
      vm_normal_page()
      {
      	...
              if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
                      if (vma->vm_flags & VM_MIXEDMAP) {
      #ifdef s390
      			if (!mixedmap_refcount_pte(pte))
      				return NULL;
      #else
                              if (!pfn_valid(pfn))
                                      return NULL;
      #endif
                              goto out;
                      }
      	...
      }
      
      This is fine, however if we are allowed to use a bit in the pte to determine
      refcountedness, we can use that to _completely_ replace all the vma based
      schemes.  So instead of adding more cases to the already complex vma-based
      scheme, we can have a clearly seperate and simple pte-based scheme (and get
      slightly better code generation in the process):
      
      vm_normal_page()
      {
      #ifdef s390
      	if (!mixedmap_refcount_pte(pte))
      		return NULL;
      	return pte_page(pte);
      #else
      	...
      #endif
      }
      
      And finally, we may rather make this concept usable by any architecture rather
      than making it s390 only, so implement a new type of pte state for this.
      Unfortunately the old vma based code must stay, because some architectures may
      not be able to spare pte bits.  This makes vm_normal_page a little bit more
      ugly than we would like, but the 2 cases are clearly seperate.
      
      So introduce a pte_special pte state, and use it in mm/memory.c.  It is
      currently a noop for all architectures, so this doesn't actually result in any
      compiled code changes to mm/memory.o.
      
      BTW:
      I haven't put vm_normal_page() into arch code as-per an earlier suggestion.
      The reason is that, regardless of where vm_normal_page is actually
      implemented, the *abstraction* is still exactly the same. Also, while it
      depends on whether the architecture has pte_special or not, that is the
      only two possible cases, and it really isn't an arch specific function --
      the role of the arch code should be to provide primitive functions and
      accessors with which to build the core code; pte_special does that. We do
      not want architectures to know or care about vm_normal_page itself, and
      we definitely don't want them being able to invent something new there
      out of sight of mm/ code. If we made vm_normal_page an arch function, then
      we have to make vm_insert_mixed (next patch) an arch function too. So I
      don't think moving it to arch code fundamentally improves any abstractions,
      while it does practically make the code more difficult to follow, for both
      mm and arch developers, and easier to misuse.
      
      [akpm@linux-foundation.org: build fix]
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Acked-by: default avatarCarsten Otte <cotte@de.ibm.com>
      Cc: Jared Hulbert <jaredeh@gmail.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7e675137
    • Jared Hulbert's avatar
      mm: introduce VM_MIXEDMAP · b379d790
      Jared Hulbert authored
      
      
      This series introduces some important infrastructure work.  The overall result
      is that:
      
      1. We now support XIP backed filesystems using memory that have no
         struct page allocated to them. And patches 6 and 7 actually implement
         this for s390.
      
         This is pretty important in a number of cases. As far as I understand,
         in the case of virtualisation (eg. s390), each guest may mount a
         readonly copy of the same filesystem (eg. the distro). Currently,
         guests need to allocate struct pages for this image. So if you have
         100 guests, you already need to allocate more memory for the struct
         pages than the size of the image. I think. (Carsten?)
      
         For other (eg. embedded) systems, you may have a very large non-
         volatile filesystem. If you have to have struct pages for this, then
         your RAM consumption will go up proportionally to fs size. Even
         though it is just a small proportion, the RAM can be much more costly
         eg in terms of power, so every KB less that Linux uses makes it more
         attractive to a lot of these guys.
      
      2. VM_MIXEDMAP allows us to support mappings where you actually do want
         to refcount _some_ pages in the mapping, but not others, and support
         COW on arbitrary (non-linear) mappings. Jared needs this for his NVRAM
         filesystem in progress. Future iterations of this filesystem will
         most likely want to migrate pages between pagecache and XIP backing,
         which is where the requirement for mixed (some refcounted, some not)
         comes from.
      
      3. pte_special also has a peripheral usage that I need for my lockless
         get_user_pages patch. That was shown to speed up "oltp" on db2 by
         10% on a 2 socket system, which is kind of significant because they
         scrounge for months to try to find 0.1% improvement on these
         workloads. I'm hoping we might finally be faster than AIX on
         pSeries with this :). My reference to lockless get_user_pages is not
         meant to justify this patchset (which doesn't include lockless gup),
         but just to show that pte_special is not some s390 specific thing that
         should be hidden in arch code or xip code: I definitely want to use it
         on at least x86 and powerpc as well.
      
      This patch:
      
      Introduce a new type of mapping, VM_MIXEDMAP.  This is unlike VM_PFNMAP in
      that it can support COW mappings of arbitrary ranges including ranges without
      struct page *and* ranges with a struct page that we actually want to refcount
      (PFNMAP can only support COW in those cases where the un-COW-ed translations
      are mapped linearly in the virtual address, and can only support non
      refcounted ranges).
      
      VM_MIXEDMAP achieves this by refcounting all pfn_valid pages, and not
      refcounting !pfn_valid pages (which is not an option for VM_PFNMAP, because it
      needs to avoid refcounting pfn_valid pages eg.  for /dev/mem mappings).
      
      Signed-off-by: default avatarJared Hulbert <jaredeh@gmail.com>
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Acked-by: default avatarCarsten Otte <cotte@de.ibm.com>
      Cc: Jared Hulbert <jaredeh@gmail.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b379d790
    • Peter Zijlstra's avatar
      smaps: account swap entries · 214e471f
      Peter Zijlstra authored
      
      
      Show the amount of swap for each vma.  This can be used to see where all the
      swap goes.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Acked-by: default avatarMatt Mackall <mpm@selenic.com>
      Acked-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      214e471f
    • Christoph Lameter's avatar
      PAGEFLAGS_EXTENDED and separate page flags for Head and Tail · e20b8cca
      Christoph Lameter authored
      
      
      Having separate page flags for the head and the tail of a compound page allows
      the compiler to use bitops instead of operations on a word to check for a tail
      page.  That is f.e.  important for virt_to_head_page() which is used in
      various critical code paths (kfree for example):
      
      Code for PageTail(page)
      
      Before:
      
       mov    (%rdi),%rdx		page->flags
       mov    %rdx,%rax		3 bytes
       and    $0x12000,%eax		5 bytes
       cmp    $0x12000,%rax		6 bytes
       je     897 <kfree+0xa7>
      
      After:
      
       mov    (%rdi),%rax
       test   $0x40,%ah			(3 bytes)
       jne    887 <kfree+0x97>
      
      So we go from 14 bytes to 3 bytes and from 3 instructions to one.  From the
      use of 2 registers we go to none.
      
      We can only use page flags for this if we have page flags available.  This
      patch introduces CONFIG_PAGEFLAGS_EXTENDED that is set if pageflags are not
      scarce due to SPARSEMEM using page flags for its sectionid on 32 bit NUMA
      platforms.
      
      Additional page flag definitions can be added to the CONFIG_PAGEFLAGS_EXTENDED
      section in page-flags.h if the functionality depends on PAGEFLAGS_EXTENDED or
      if more page flag overlapping tricks are used for the !PAGEFLAGS_EXTENDED
      fallback (the upcoming virtual compound patch may hook in here and Rik's/Lee's
      additional page flags to solve the reclaim issues could also be added there
      [hint...  hint...  where are these patchsets?]).
      
      Avoiding the overlaying of Pg_reclaim also clears the way for possible use of
      compound pages for the pagecache or on the LRU.
      
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e20b8cca
    • Christoph Lameter's avatar
      mm: Get rid of __ZONE_COUNT · 97965478
      Christoph Lameter authored
      
      
      It was used to compensate because MAX_NR_ZONES was not available to the
      #ifdefs.  Export MAX_NR_ZONES via the new mechanism and get rid of
      __ZONE_COUNT.
      
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      97965478
    • Christoph Lameter's avatar
      page flags: add PAGEFLAGS_FALSE for flags that are always false · ec7cade8
      Christoph Lameter authored
      
      
      Turns out that there are a number of times that a flag is simply always
      returning 0.  Define a macro for that.
      
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ec7cade8
    • Christoph Lameter's avatar
      page flags: handle PG_uncached like all other flags · 602c4d11
      Christoph Lameter authored
      
      
      Remove the special setup for PG_uncached and simply make it part of the enum.
      The page flag will only be allocated when the kernel build includes the
      uncached allocator.
      
      Acked-by: default avatarDean Nelson <dcn@sgi.com>
      Cc: Jes Sorensen <jes@trained-monkey.org>
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      602c4d11
    • Christoph Lameter's avatar
      pageflags: eliminate PG_xxx aliases · 0a128b2b
      Christoph Lameter authored
      
      
      Remove aliases of PG_xxx.  We can easily drop those now and alias by
      specifying the PG_xxx flag in the macro that generates the functions.
      
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: Andy Whitcroft <apw@shadowen.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0a128b2b
    • Christoph Lameter's avatar
      pageflags: use proper page flag functions in Xen · d60cd46b
      Christoph Lameter authored
      
      
      Xen uses bitops to manipulate page flags.  Make it use proper page flag
      functions.
      
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: Andy Whitcroft <apw@shadowen.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d60cd46b
    • Christoph Lameter's avatar
      pageflags: convert to the use of new macros · 6a1e7f77
      Christoph Lameter authored
      
      
      Replace explicit definitions of page flags through the use of macros.
      Significantly reduces the size of the definitions and removes a lot of
      opportunity for errors.  Additonal page flags can typically be generated with
      a single line.
      
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: Andy Whitcroft <apw@shadowen.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6a1e7f77
    • Christoph Lameter's avatar
      pageflags: introduce macros to generate page flag functions · f94a62e9
      Christoph Lameter authored
      
      
      Introduce a set of macros that generate functions to handle page flags.
      
      A page flag function group typically starts with either
      
      	SETPAGEFLAG(<part of function name>,<part of PG_ flagname>)
      
      to create a set of page flag operations that are atomic. Or
      
      	__SETPAGEFLAG(<part of function name>,<part of PG_ flagname)
      
      to create a set of page flag operations that are not atomic.
      
      Then additional operations can be added using the following macros
      
      TESTSCFLAG		Create additional atomic test-and-set and
      			test-and-clear functions
      
      TESTSETFLAG		Create additional test and set function
      TESTCLEARFLAG		Create additional test and clear function
      SETPAGEFLAG		Create additional atomic set function
      CLEARPAGEFLAG		Create additional atomic clear function
      __TESTPAGEFLAG		Create additional non atomic set function
      __SETPAGEFLAG		Create additional non atomic clear function
      
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: Andy Whitcroft <apw@shadowen.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f94a62e9
    • Christoph Lameter's avatar
      pageflags: get rid of FLAGS_RESERVED · 9223b419
      Christoph Lameter authored
      
      
      NR_PAGEFLAGS specifies the number of page flags we are using.  From that we
      can calculate the number of bits leftover that can be used for zone, node (and
      maybe the sections id).  There is no need anymore for FLAGS_RESERVED if we use
      NR_PAGEFLAGS.
      
      Use the new methods to make NR_PAGEFLAGS available via the preprocessor.
      NR_PAGEFLAGS is used to calculate field boundaries in the page flags fields.
      These field widths have to be available to the preprocessor.
      
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Andy Whitcroft <apw@shadowen.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9223b419
    • Christoph Lameter's avatar
      pageflags: use an enum for the flags · e2683181
      Christoph Lameter authored
      
      
      Use an enum to ease the maintenance of page flags.  This is going to change
      the numbering from 0 to 18.
      
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: Andy Whitcroft <apw@shadowen.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e2683181
    • Christoph Lameter's avatar
      pageflags: standardize comment inclusion in asm-offsets.h and fix MIPS · bf2ae2b3
      Christoph Lameter authored
      
      
      Add the ability to pass comments into asm-offsets.h by generating asm
      output like
      
      -># comment line
      
      Mips needs this feature to preserve the comments that are in
      asm-mips/asm-offsets.h right now.
      
      Then remove the special handling for mips from Kbuild and convert mips to use
      the new string to include the comments.
      
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      bf2ae2b3
    • Andrew Morton's avatar
      page_mapping(): add ifdef around reference to swapper_space · 726b8012
      Andrew Morton authored
      
      
      This fixes the superh build when the pageflags patches are applied.
      
      But it shouldn't unless it's a gcc bug.
      
      Cc: Christoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      726b8012
    • Christoph Lameter's avatar
      kbuild: create a way to create preprocessor constants from C expressions · 1cdf25d7
      Christoph Lameter authored
      
      
      The use of enums create constants that are not available to the preprocessor
      when building the kernel (f.e.  MAX_NR_ZONES).
      
      Arch code already has a way to export constants calculated to the preprocessor
      through the asm-offsets.c file.  Generate something similar for the core
      kernel through kbuild.
      
      Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: Andy Whitcroft <apw@shadowen.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1cdf25d7
    • Christoph Lameter's avatar
      sparsemem: vmemmap does not need section bits · 308c05e3
      Christoph Lameter authored
      
      
      A set of patches that attempts to improve page flag handling.  First of all a
      method is introduced to generate the page flag functions using macros.  Then
      the number of page flags used by sparsemem is reduced.  All page flag
      operations will no longer be macros.  All flags will use inline function.
      
      Then we add a way to export enum constants to the preprocessor which allows us
      to get rid of __ZONE_COUNT and use the NR_PAGEFLAGS for the dynamic
      calculation of actually available page flags for fields.
      
      This patch:
      
      Sparsemem vmemmap does not need any section bits.  This patch has the effect
      of reducing the number of bits used in page->flags by at least 6.
      
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: Andy Whitcroft <apw@shadowen.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      308c05e3
    • Christoph Lameter's avatar
      vmallocinfo: add caller information · 23016969
      Christoph Lameter authored
      
      
      Add caller information so that /proc/vmallocinfo shows where the allocation
      request for a slice of vmalloc memory originated.
      
      Results in output like this:
      
      0xffffc20000000000-0xffffc20000801000 8392704 alloc_large_system_hash+0x127/0x246 pages=2048 vmalloc vpages
      0xffffc20000801000-0xffffc20000806000   20480 alloc_large_system_hash+0x127/0x246 pages=4 vmalloc
      0xffffc20000806000-0xffffc20000c07000 4198400 alloc_large_system_hash+0x127/0x246 pages=1024 vmalloc vpages
      0xffffc20000c07000-0xffffc20000c0a000   12288 alloc_large_system_hash+0x127/0x246 pages=2 vmalloc
      0xffffc20000c0a000-0xffffc20000c0c000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
      0xffffc20000c0c000-0xffffc20000c0f000   12288 acpi_os_map_memory+0x13/0x1c phys=cff64000 ioremap
      0xffffc20000c10000-0xffffc20000c15000   20480 acpi_os_map_memory+0x13/0x1c phys=cff65000 ioremap
      0xffffc20000c16000-0xffffc20000c18000    8192 acpi_os_map_memory+0x13/0x1c phys=cff69000 ioremap
      0xffffc20000c18000-0xffffc20000c1a000    8192 acpi_os_map_memory+0x13/0x1c phys=fed1f000 ioremap
      0xffffc20000c1a000-0xffffc20000c1c000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
      0xffffc20000c1c000-0xffffc20000c1e000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
      0xffffc20000c1e000-0xffffc20000c20000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
      0xffffc20000c20000-0xffffc20000c22000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
      0xffffc20000c22000-0xffffc20000c24000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
      0xffffc20000c24000-0xffffc20000c26000    8192 acpi_os_map_memory+0x13/0x1c phys=e0081000 ioremap
      0xffffc20000c26000-0xffffc20000c28000    8192 acpi_os_map_memory+0x13/0x1c phys=e0080000 ioremap
      0xffffc20000c28000-0xffffc20000c2d000   20480 alloc_large_system_hash+0x127/0x246 pages=4 vmalloc
      0xffffc20000c2d000-0xffffc20000c31000   16384 tcp_init+0xd5/0x31c pages=3 vmalloc
      0xffffc20000c31000-0xffffc20000c34000   12288 alloc_large_system_hash+0x127/0x246 pages=2 vmalloc
      0xffffc20000c34000-0xffffc20000c36000    8192 init_vdso_vars+0xde/0x1f1
      0xffffc20000c36000-0xffffc20000c38000    8192 pci_iomap+0x8a/0xb4 phys=d8e00000 ioremap
      0xffffc20000c38000-0xffffc20000c3a000    8192 usb_hcd_pci_probe+0x139/0x295 [usbcore] phys=d8e00000 ioremap
      0xffffc20000c3a000-0xffffc20000c3e000   16384 sys_swapon+0x509/0xa15 pages=3 vmalloc
      0xffffc20000c40000-0xffffc20000c61000  135168 e1000_probe+0x1c4/0xa32 phys=d8a20000 ioremap
      0xffffc20000c61000-0xffffc20000c6a000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
      0xffffc20000c6a000-0xffffc20000c73000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
      0xffffc20000c73000-0xffffc20000c7c000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
      0xffffc20000c7c000-0xffffc20000c7f000   12288 e1000e_setup_tx_resources+0x29/0xbe pages=2 vmalloc
      0xffffc20000c80000-0xffffc20001481000 8392704 pci_mmcfg_arch_init+0x90/0x118 phys=e0000000 ioremap
      0xffffc20001481000-0xffffc20001682000 2101248 alloc_large_system_hash+0x127/0x246 pages=512 vmalloc
      0xffffc20001682000-0xffffc20001e83000 8392704 alloc_large_system_hash+0x127/0x246 pages=2048 vmalloc vpages
      0xffffc20001e83000-0xffffc20002204000 3674112 alloc_large_system_hash+0x127/0x246 pages=896 vmalloc vpages
      0xffffc20002204000-0xffffc2000220d000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
      0xffffc2000220d000-0xffffc20002216000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
      0xffffc20002216000-0xffffc2000221f000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
      0xffffc2000221f000-0xffffc20002228000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
      0xffffc20002228000-0xffffc20002231000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
      0xffffc20002231000-0xffffc20002234000   12288 e1000e_setup_rx_resources+0x35/0x122 pages=2 vmalloc
      0xffffc20002240000-0xffffc20002261000  135168 e1000_probe+0x1c4/0xa32 phys=d8a60000 ioremap
      0xffffc20002261000-0xffffc2000270c000 4894720 sys_swapon+0x509/0xa15 pages=1194 vmalloc vpages
      0xffffffffa0000000-0xffffffffa0022000  139264 module_alloc+0x4f/0x55 pages=33 vmalloc
      0xffffffffa0022000-0xffffffffa0029000   28672 module_alloc+0x4f/0x55 pages=6 vmalloc
      0xffffffffa002b000-0xffffffffa0034000   36864 module_alloc+0x4f/0x55 pages=8 vmalloc
      0xffffffffa0034000-0xffffffffa003d000   36864 module_alloc+0x4f/0x55 pages=8 vmalloc
      0xffffffffa003d000-0xffffffffa0049000   49152 module_alloc+0x4f/0x55 pages=11 vmalloc
      0xffffffffa0049000-0xffffffffa0050000   28672 module_alloc+0x4f/0x55 pages=6 vmalloc
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Reviewed-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Hugh Dickins <hugh@veritas.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      23016969
    • Christoph Lameter's avatar
      vmalloc: show vmalloced areas via /proc/vmallocinfo · a10aa579
      Christoph Lameter authored
      
      
      Implement a new proc file that allows the display of the currently allocated
      vmalloc memory.
      
      It allows to see the users of vmalloc.  That is important if vmalloc space is
      scarce (i386 for example).
      
      And it's going to be important for the compound page fallback to vmalloc.
      Many of the current users can be switched to use compound pages with fallback.
       This means that the number of users of vmalloc is reduced and page tables no
      longer necessary to access the memory.  /proc/vmallocinfo allows to review how
      that reduction occurs.
      
      If memory becomes fragmented and larger order allocations are no longer
      possible then /proc/vmallocinfo allows to see which compound page allocations
      fell back to virtual compound pages.  That is important for new users of
      virtual compound pages.  Such as order 1 stack allocation etc that may
      fallback to virtual compound pages in the future.
      
      /proc/vmallocinfo permissions are made readable-only-by-root to avoid possible
      information leakage.
      
      [akpm@linux-foundation.org: coding-style fixes]
      [akpm@linux-foundation.org: CONFIG_MMU=n build fix]
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Reviewed-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Hugh Dickins <hugh@veritas.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Cc: Arjan van de Ven <arjan@infradead.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a10aa579
    • Andrew Morton's avatar
      mm: make early_pfn_to_nid() a C function · b4544568
      Andrew Morton authored
      
      
      Fix this (sparc64)
      
      mm/sparse-vmemmap.c: In function `vmemmap_verify':
      mm/sparse-vmemmap.c:64: warning: unused variable `pfn'
      
      by switching to a C function which touches its arg.
      
      (reason 3,555 why macros are bad)
      
      Also, the `nid' arg was misnamed.
      
      Reviewed-by: default avatarChristoph Lameter <clameter@sgi.com>
      Acked-by: default avatarAndy Whitcroft <apw@shadowen.org>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Andi Kleen <ak@suse.de>
      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>
      b4544568
    • Miklos Szeredi's avatar
      mm: rotate_reclaimable_page() cleanup · ac6aadb2
      Miklos Szeredi authored
      
      
      Clean up messy conditional calling of test_clear_page_writeback() from both
      rotate_reclaimable_page() and end_page_writeback().
      
      The only user of rotate_reclaimable_page() is end_page_writeback() so this is
      OK.
      
      Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ac6aadb2
    • S.Caglar Onur's avatar
      mm/page_alloc.c: fix indentation · f05111f5
      S.Caglar Onur authored
      zlc_setup(): handle jiffies wraparound
      (10ed273f
      
      ) changes tab with spaces
      
      Signed-off-by: default avatarS.Caglar Onur <caglar@pardus.org.tr>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      Cc: Paul Jackson <pj@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f05111f5
    • Andi Kleen's avatar
      mm: save some bytes in mm_struct by filling holes on 64bit · 7edf85aa
      Andi Kleen authored
      
      
      Save some bytes in mm_struct by filling holes
      
      Putting int values together for better packing on 64bit shrinks sizeof(struct
      mm_struct) from 776 bytes to 764 bytes.
      
      Signed-off-by: default avatarAndi Kleen <ak@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7edf85aa
    • Andi Kleen's avatar
      dmapool: enable debugging for CONFIG_SLUB_DEBUG_ON too · b5ee5bef
      Andi Kleen authored
      
      
      Previously it was only enabled for CONFIG_DEBUG_SLAB.
      
      Not hooked into the slub runtime debug configuration, so you currently only
      get it with CONFIG_SLUB_DEBUG_ON, not plain CONFIG_SLUB_DEBUG
      
      Acked-by: default avatarMatthew Wilcox <willy@linux.intel.com>
      Signed-off-by: default avatarAndi Kleen <ak@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b5ee5bef
    • Lee Schermerhorn's avatar
      mempolicy: fix parsing of tmpfs mpol mount option · a43361cf
      Lee Schermerhorn authored
      
      
      Parsing of new mode flags in the tmpfs mpol mount option is slightly broken:
      
      Setting a valid flag works OK:
      	#mount -o remount,mpol=bind=static:1-2 /dev/shm
      	#mount
      	...
      	tmpfs on /dev/shm type tmpfs (rw,mpol=bind=static:1-2)
      	...
      
      However, we can't remove them or change them, once we've
      set a valid flag:
      
      	#mount -o remount,mpol=bind:1-2 /dev/shm
      	#mount
      	...
      	tmpfs on /dev/shm type tmpfs (rw,mpol=bind:1-2)
      	...
      
      It SAYS it removed it, but that's just a copy of the input
      string.  If we now try to set it to a different flag, we
      get:
      
      	#mount -o remount,mpol=bind=relative:1-2 /dev/shm
      	mount: /dev/shm not mounted already, or bad option
      
      And on the console, we see:
      	tmpfs: Bad value 'bind' for mount option 'mpol'
      	                      ^ lost remainder of string
      
      Furthermore, bogus flags are accepted with out error.
      Granted, they are a no-op:
      
      	#mount -o remount,mpol=interleave=foo:0-3 /dev/shm
      	#mount
      	...
      	tmpfs on /dev/shm type tmpfs (rw,mpol=interleave=foo:0-3)
      
      Again, that's just a copy of the input string shown by the mount command.
      
      This patch fixes the behavior by pre-zeroing the flags so that only one of the
      mutually exclusive flags can be set at one time.  It also reports an error
      when an unrecognized flag is specified.
      
      The check for both flags being set is removed because it can't happen with
      this implementation.  If we ever want to support multiple non-exclusive flags,
      this area will need rework and we will need to check that any mutually
      exclusive flags aren't specified.
      
      Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Paul Jackson <pj@sgi.com>
      Cc: Christoph Lameter <clameter@sgi.com>
      Cc: Andi Kleen <ak@suse.de>
      Cc: Eric Whitney <eric.whitney@hp.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a43361cf
    • David Rientjes's avatar
      mempolicy: disallow static or relative flags for local preferred mode · 3e1f0645
      David Rientjes authored
      
      
      MPOL_F_STATIC_NODES and MPOL_F_RELATIVE_NODES don't mean anything for
      MPOL_PREFERRED policies that were created with an empty nodemask (for purely
      local allocations).  They'll never be invalidated because the allowed mems of
      a task changes or need to be rebound relative to a cpuset's placement.
      
      Also fixes a bug identified by Lee Schermerhorn that disallowed empty
      nodemasks to be passed to MPOL_PREFERRED to specify local allocations.  [A
      different, somewhat incomplete, patch already existed in 25-rc5-mm1.]
      
      Cc: Paul Jackson <pj@sgi.com>
      Cc: Christoph Lameter <clameter@sgi.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      Cc: Andi Kleen <ak@suse.de>
      Cc: Randy Dunlap <randy.dunlap@oracle.com>
      Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3e1f0645