1. 14 Nov, 2007 3 commits
  2. 16 Oct, 2007 1 commit
  3. 31 Aug, 2007 1 commit
    • David Gibson's avatar
      hugepage: fix broken check for offset alignment in hugepage mappings · dec4ad86
      David Gibson authored
      For hugepage mappings, the file offset, like the address and size, needs to
      be aligned to the size of a hugepage.
      
      In commit 68589bc3, the check for this was
      moved into prepare_hugepage_range() along with the address and size checks.
       But since BenH's rework of the get_unmapped_area() paths leading up to
      commit 4b1d8929, prepare_hugepage_range()
      is only called for MAP_FIXED mappings, not for other mappings.  This means
      we're no longer ever checking for an aligned offset - I've confirmed that
      mmap() will (apparently) succeed with a misaligned offset on both powerpc
      and i386 at least.
      
      This patch restores the check, removing it from prepare_hugepage_range()
      and putting it back into hugetlbfs_file_mmap().  I'm putting it there,
      rather than in the get_unmapped_area() path so it only needs to go in one
      place, than separately in the half-dozen or so arch-specific
      implementations of hugetlb_get_unmapped_area().
      Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
      Cc: Adam Litke <agl@us.ibm.com>
      Cc: Andi Kleen <ak@suse.de>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      dec4ad86
  4. 29 Jul, 2007 1 commit
    • Alexey Dobriyan's avatar
      Remove fs.h from mm.h · 4e950f6f
      Alexey Dobriyan authored
      Remove fs.h from mm.h. For this,
       1) Uninline vma_wants_writenotify(). It's pretty huge anyway.
       2) Add back fs.h or less bloated headers (err.h) to files that need it.
      
      As result, on x86_64 allyesconfig, fs.h dependencies cut down from 3929 files
      rebuilt down to 3444 (-12.3%).
      
      Cross-compile tested without regressions on my two usual configs and (sigh):
      
      alpha              arm-mx1ads        mips-bigsur          powerpc-ebony
      alpha-allnoconfig  arm-neponset      mips-capcella        powerpc-g5
      alpha-defconfig    arm-netwinder     mips-cobalt          powerpc-holly
      alpha-up           arm-netx          mips-db1000          powerpc-iseries
      arm                arm-ns9xxx        mips-db1100          powerpc-linkstation
      arm-assabet        arm-omap_h2_1610  mips-db1200          powerpc-lite5200
      arm-at91rm9200dk   arm-onearm        mips-db1500          powerpc-maple
      arm-at91rm9200ek   arm-picotux200    mips-db1550          powerpc-mpc7448_hpc2
      arm-at91sam9260ek  arm-pleb          mips-ddb5477         powerpc-mpc8272_ads
      arm-at91sam9261ek  arm-pnx4008       mips-decstation      powerpc-mpc8313_rdb
      arm-at91sam9263ek  arm-pxa255-idp    mips-e55             powerpc-mpc832x_mds
      arm-at91sam9rlek   arm-realview      mips-emma2rh         powerpc-mpc832x_rdb
      arm-ateb9200       arm-realview-smp  mips-excite          powerpc-mpc834x_itx
      arm-badge4         arm-rpc           mips-fulong          powerpc-mpc834x_itxgp
      arm-carmeva        arm-s3c2410       mips-ip22            powerpc-mpc834x_mds
      arm-cerfcube       arm-shannon       mips-ip27            powerpc-mpc836x_mds
      arm-clps7500       arm-shark         mips-ip32            powerpc-mpc8540_ads
      arm-collie         arm-simpad        mips-jazz            powerpc-mpc8544_ds
      arm-corgi          arm-spitz         mips-jmr3927         powerpc-mpc8560_ads
      arm-csb337         arm-trizeps4      mips-malta           powerpc-mpc8568mds
      arm-csb637         arm-versatile     mips-mipssim         powerpc-mpc85xx_cds
      arm-ebsa110        i386              mips-mpc30x          powerpc-mpc8641_hpcn
      arm-edb7211        i386-allnoconfig  mips-msp71xx         powerpc-mpc866_ads
      arm-em_x270        i386-defconfig    mips-ocelot          powerpc-mpc885_ads
      arm-ep93xx         i386-up           mips-pb1100          powerpc-pasemi
      arm-footbridge     ia64              mips-pb1500          powerpc-pmac32
      arm-fortunet       ia64-allnoconfig  mips-pb1550          powerpc-ppc64
      arm-h3600          ia64-bigsur       mips-pnx8550-jbs     powerpc-prpmc2800
      arm-h7201          ia64-defconfig    mips-pnx8550-stb810  powerpc-ps3
      arm-h7202          ia64-gensparse    mips-qemu            powerpc-pseries
      arm-hackkit        ia64-sim          mips-rbhma4200       powerpc-up
      arm-integrator     ia64-sn2          mips-rbhma4500       s390
      arm-iop13xx        ia64-tiger        mips-rm200           s390-allnoconfig
      arm-iop32x         ia64-up           mips-sb1250-swarm    s390-defconfig
      arm-iop33x         ia64-zx1          mips-sead            s390-up
      arm-ixp2000        m68k              mips-tb0219          sparc
      arm-ixp23xx        m68k-amiga        mips-tb0226          sparc-allnoconfig
      arm-ixp4xx         m68k-apollo       mips-tb0287          sparc-defconfig
      arm-jornada720     m68k-atari        mips-workpad         sparc-up
      arm-kafa           m68k-bvme6000     mips-wrppmc          sparc64
      arm-kb9202         m68k-hp300        mips-yosemite        sparc64-allnoconfig
      arm-ks8695         m68k-mac          parisc               sparc64-defconfig
      arm-lart           m68k-mvme147      parisc-allnoconfig   sparc64-up
      arm-lpd270         m68k-mvme16x      parisc-defconfig     um-x86_64
      arm-lpd7a400       m68k-q40          parisc-up            x86_64
      arm-lpd7a404       m68k-sun3         powerpc              x86_64-allnoconfig
      arm-lubbock        m68k-sun3x        powerpc-cell         x86_64-defconfig
      arm-lusl7200       mips              powerpc-celleb       x86_64-up
      arm-mainstone      mips-atlas        powerpc-chrp32
      Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4e950f6f
  5. 17 Jul, 2007 1 commit
    • Mel Gorman's avatar
      Allow huge page allocations to use GFP_HIGH_MOVABLE · 396faf03
      Mel Gorman authored
      Huge pages are not movable so are not allocated from ZONE_MOVABLE.  However,
      as ZONE_MOVABLE will always have pages that can be migrated or reclaimed, it
      can be used to satisfy hugepage allocations even when the system has been
      running a long time.  This allows an administrator to resize the hugepage pool
      at runtime depending on the size of ZONE_MOVABLE.
      
      This patch adds a new sysctl called hugepages_treat_as_movable.  When a
      non-zero value is written to it, future allocations for the huge page pool
      will use ZONE_MOVABLE.  Despite huge pages being non-movable, we do not
      introduce additional external fragmentation of note as huge pages are always
      the largest contiguous block we care about.
      
      [akpm@linux-foundation.org: various fixes]
      Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      396faf03
  6. 16 Jun, 2007 1 commit
    • Eric W. Biederman's avatar
      shm: fix the filename of hugetlb sysv shared memory · 9d66586f
      Eric W. Biederman authored
      Some user space tools need to identify SYSV shared memory when examining
      /proc/<pid>/maps.  To do so they look for a block device with major zero, a
      dentry named SYSV<sysv key>, and having the minor of the internal sysv
      shared memory kernel mount.
      
      To help these tools and to make it easier for people just browsing
      /proc/<pid>/maps this patch modifies hugetlb sysv shared memory to use the
      SYSV<key> dentry naming convention.
      
      User space tools will still have to be aware that hugetlb sysv shared
      memory lives on a different internal kernel mount and so has a different
      block device minor number from the rest of sysv shared memory.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Cc: "Serge E. Hallyn" <serge@hallyn.com>
      Cc: Albert Cahalan <acahalan@gmail.com>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9d66586f
  7. 07 May, 2007 1 commit
  8. 01 Mar, 2007 1 commit
    • Adam Litke's avatar
      [PATCH] Fix get_unmapped_area and fsync for hugetlb shm segments · 516dffdc
      Adam Litke authored
      This patch provides the following hugetlb-related fixes to the recent stacked
      shm files changes:
       - Update is_file_hugepages() so it will reconize hugetlb shm segments.
       - get_unmapped_area must be called with the nested file struct to handle
         the sfd->file->f_ops->get_unmapped_area == NULL case.
       - The fsync f_op must be wrapped since it is specified in the hugetlbfs
         f_ops.
      
      This is based on proposed fixes from Eric Biederman that were debugged and
      tested by me.  Without it, attempting to use hugetlb shared memory segments
      on powerpc (and likely ia64) will kill your box.
      Signed-off-by: default avatarAdam Litke <agl@us.ibm.com>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Acked-by: default avatarWilliam Irwin <bill.irwin@oracle.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      516dffdc
  9. 07 Dec, 2006 1 commit
    • Chen, Kenneth W's avatar
      [PATCH] shared page table for hugetlb page · 39dde65c
      Chen, Kenneth W authored
      Following up with the work on shared page table done by Dave McCracken.  This
      set of patch target shared page table for hugetlb memory only.
      
      The shared page table is particular useful in the situation of large number of
      independent processes sharing large shared memory segments.  In the normal
      page case, the amount of memory saved from process' page table is quite
      significant.  For hugetlb, the saving on page table memory is not the primary
      objective (as hugetlb itself already cuts down page table overhead
      significantly), instead, the purpose of using shared page table on hugetlb is
      to allow faster TLB refill and smaller cache pollution upon TLB miss.
      
      With PT sharing, pte entries are shared among hundreds of processes, the cache
      consumption used by all the page table is smaller and in return, application
      gets much higher cache hit ratio.  One other effect is that cache hit ratio
      with hardware page walker hitting on pte in cache will be higher and this
      helps to reduce tlb miss latency.  These two effects contribute to higher
      application performance.
      Signed-off-by: default avatarKen Chen <kenneth.w.chen@intel.com>
      Acked-by: default avatarHugh Dickins <hugh@veritas.com>
      Cc: Dave McCracken <dmccr@us.ibm.com>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: David Gibson <david@gibson.dropbear.id.au>
      Cc: Adam Litke <agl@us.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: "David S. Miller" <davem@davemloft.net>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      39dde65c
  10. 14 Nov, 2006 1 commit
    • Hugh Dickins's avatar
      [PATCH] hugetlb: prepare_hugepage_range check offset too · 68589bc3
      Hugh Dickins authored
      (David:)
      
      If hugetlbfs_file_mmap() returns a failure to do_mmap_pgoff() - for example,
      because the given file offset is not hugepage aligned - then do_mmap_pgoff
      will go to the unmap_and_free_vma backout path.
      
      But at this stage the vma hasn't been marked as hugepage, and the backout path
      will call unmap_region() on it.  That will eventually call down to the
      non-hugepage version of unmap_page_range().  On ppc64, at least, that will
      cause serious problems if there are any existing hugepage pagetable entries in
      the vicinity - for example if there are any other hugepage mappings under the
      same PUD.  unmap_page_range() will trigger a bad_pud() on the hugepage pud
      entries.  I suspect this will also cause bad problems on ia64, though I don't
      have a machine to test it on.
      
      (Hugh:)
      
      prepare_hugepage_range() should check file offset alignment when it checks
      virtual address and length, to stop MAP_FIXED with a bad huge offset from
      unmapping before it fails further down.  PowerPC should apply the same
      prepare_hugepage_range alignment checks as ia64 and all the others do.
      
      Then none of the alignment checks in hugetlbfs_file_mmap are required (nor
      is the check for too small a mapping); but even so, move up setting of
      VM_HUGETLB and add a comment to warn of what David Gibson discovered - if
      hugetlbfs_file_mmap fails before setting it, do_mmap_pgoff's unmap_region
      when unwinding from error will go the non-huge way, which may cause bad
      behaviour on architectures (powerpc and ia64) which segregate their huge
      mappings into a separate region of the address space.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Acked-by: default avatarAdam Litke <agl@us.ibm.com>
      Acked-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      68589bc3
  11. 11 Oct, 2006 1 commit
  12. 23 Jun, 2006 1 commit
    • Chen, Kenneth W's avatar
      [PATCH] tightening hugetlb strict accounting · a43a8c39
      Chen, Kenneth W authored
      Current hugetlb strict accounting for shared mapping always assume mapping
      starts at zero file offset and reserves pages between zero and size of the
      file.  This assumption often reserves (or lock down) a lot more pages then
      necessary if application maps at none zero file offset.  libhugetlbfs is
      one example that requires proper reservation on shared mapping starts at
      none zero offset.
      
      This patch extends the reservation and hugetlb strict accounting to support
      any arbitrary pair of (offset, len), resulting a much more robust and
      accurate scheme.  More importantly, it won't lock down any hugetlb pages
      outside file mapping.
      Signed-off-by: default avatarKen Chen <kenneth.w.chen@intel.com>
      Acked-by: default avatarAdam Litke <agl@us.ibm.com>
      Cc: David Gibson <david@gibson.dropbear.id.au>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      a43a8c39
  13. 28 Mar, 2006 1 commit
  14. 22 Mar, 2006 6 commits
    • David Gibson's avatar
      [PATCH] hugepage: is_aligned_hugepage_range() cleanup · 42b88bef
      David Gibson authored
      Quite a long time back, prepare_hugepage_range() replaced
      is_aligned_hugepage_range() as the callback from mm/mmap.c to arch code to
      verify if an address range is suitable for a hugepage mapping.
      is_aligned_hugepage_range() stuck around, but only to implement
      prepare_hugepage_range() on archs which didn't implement their own.
      
      Most archs (everything except ia64 and powerpc) used the same
      implementation of is_aligned_hugepage_range().  On powerpc, which
      implements its own prepare_hugepage_range(), the custom version was never
      used.
      
      In addition, "is_aligned_hugepage_range()" was a bad name, because it
      suggests it returns true iff the given range is a good hugepage range,
      whereas in fact it returns 0-or-error (so the sense is reversed).
      
      This patch cleans up by abolishing is_aligned_hugepage_range().  Instead
      prepare_hugepage_range() is defined directly.  Most archs use the default
      version, which simply checks the given region is aligned to the size of a
      hugepage.  ia64 and powerpc define custom versions.  The ia64 one simply
      checks that the range is in the correct address space region in addition to
      being suitably aligned.  The powerpc version (just as previously) checks
      for suitable addresses, and if necessary performs low-level MMU frobbing to
      set up new areas for use by hugepages.
      
      No libhugetlbfs testsuite regressions on ppc64 (POWER5 LPAR).
      Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
      Signed-off-by: default avatarZhang Yanmin <yanmin.zhang@intel.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      42b88bef
    • David Gibson's avatar
      [PATCH] hugepage: Move hugetlb_free_pgd_range() prototype to hugetlb.h · 3915bcf3
      David Gibson authored
      The optional hugepage callback, hugetlb_free_pgd_range() is presently
      implemented non-trivially only on ia64 (but I plan to add one for powerpc
      shortly).  It has its own prototype for the function in asm-ia64/pgtable.h.
       However, since the function is called from generic code, it make sense for
      its prototype to be in the generic hugetlb.h header file, as the protypes
      other arch callbacks already are (prepare_hugepage_range(),
      set_huge_pte_at(), etc.).  This patch makes it so.
      Signed-off-by: default avatarDavid Gibson <dwg@au1.ibm.com>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      3915bcf3
    • David Gibson's avatar
      [PATCH] hugepage: Fix hugepage logic in free_pgtables() · 9da61aef
      David Gibson authored
      free_pgtables() has special logic to call hugetlb_free_pgd_range() instead
      of the normal free_pgd_range() on hugepage VMAs.  However, the test it uses
      to do so is incorrect: it calls is_hugepage_only_range on a hugepage sized
      range at the start of the vma.  is_hugepage_only_range() will return true
      if the given range has any intersection with a hugepage address region, and
      in this case the given region need not be hugepage aligned.  So, for
      example, this test can return true if called on, say, a 4k VMA immediately
      preceding a (nicely aligned) hugepage VMA.
      
      At present we get away with this because the powerpc version of
      hugetlb_free_pgd_range() is just a call to free_pgd_range().  On ia64 (the
      only other arch with a non-trivial is_hugepage_only_range()) we get away
      with it for a different reason; the hugepage area is not contiguous with
      the rest of the user address space, and VMAs are not permitted in between,
      so the test can't return a false positive there.
      
      Nonetheless this should be fixed.  We do that in the patch below by
      replacing the is_hugepage_only_range() test with an explicit test of the
      VMA using is_vm_hugetlb_page().
      
      This in turn changes behaviour for platforms where is_hugepage_only_range()
      returns false always (everything except powerpc and ia64).  We address this
      by ensuring that hugetlb_free_pgd_range() is defined to be identical to
      free_pgd_range() (instead of a no-op) on everything except ia64.  Even so,
      it will prevent some otherwise possible coalescing of calls down to
      free_pgd_range().  Since this only happens for hugepage VMAs, removing this
      small optimization seems unlikely to cause any trouble.
      
      This patch causes no regressions on the libhugetlbfs testsuite - ppc64
      POWER5 (8-way), ppc64 G5 (2-way) and i386 Pentium M (UP).
      Signed-off-by: default avatarDavid Gibson <dwg@au1.ibm.com>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Acked-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      9da61aef
    • David Gibson's avatar
      [PATCH] hugepage: Make {alloc,free}_huge_page() local · 27a85ef1
      David Gibson authored
      Originally, mm/hugetlb.c just handled the hugepage physical allocation path
      and its {alloc,free}_huge_page() functions were used from the arch specific
      hugepage code.  These days those functions are only used with mm/hugetlb.c
      itself.  Therefore, this patch makes them static and removes their
      prototypes from hugetlb.h.  This requires a small rearrangement of code in
      mm/hugetlb.c to avoid a forward declaration.
      
      This patch causes no regressions on the libhugetlbfs testsuite (ppc64,
      POWER5).
      Signed-off-by: default avatarDavid Gibson <dwg@au1.ibm.com>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      27a85ef1
    • David Gibson's avatar
      [PATCH] hugepage: Strict page reservation for hugepage inodes · b45b5bd6
      David Gibson authored
      These days, hugepages are demand-allocated at first fault time.  There's a
      somewhat dubious (and racy) heuristic when making a new mmap() to check if
      there are enough available hugepages to fully satisfy that mapping.
      
      A particularly obvious case where the heuristic breaks down is where a
      process maps its hugepages not as a single chunk, but as a bunch of
      individually mmap()ed (or shmat()ed) blocks without touching and
      instantiating the pages in between allocations.  In this case the size of
      each block is compared against the total number of available hugepages.
      It's thus easy for the process to become overcommitted, because each block
      mapping will succeed, although the total number of hugepages required by
      all blocks exceeds the number available.  In particular, this defeats such
      a program which will detect a mapping failure and adjust its hugepage usage
      downward accordingly.
      
      The patch below addresses this problem, by strictly reserving a number of
      physical hugepages for hugepage inodes which have been mapped, but not
      instatiated.  MAP_SHARED mappings are thus "safe" - they will fail on
      mmap(), not later with an OOM SIGKILL.  MAP_PRIVATE mappings can still
      trigger an OOM.  (Actually SHARED mappings can technically still OOM, but
      only if the sysadmin explicitly reduces the hugepage pool between mapping
      and instantiation)
      
      This patch appears to address the problem at hand - it allows DB2 to start
      correctly, for instance, which previously suffered the failure described
      above.
      
      This patch causes no regressions on the libhugetblfs testsuite, and makes a
      test (designed to catch this problem) pass which previously failed (ppc64,
      POWER5).
      Signed-off-by: default avatarDavid Gibson <dwg@au1.ibm.com>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      b45b5bd6
    • Zhang, Yanmin's avatar
      [PATCH] Enable mprotect on huge pages · 8f860591
      Zhang, Yanmin authored
      2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
      mprotect.
      
      From: David Gibson <david@gibson.dropbear.id.au>
      
        Remove a test from the mprotect() path which checks that the mprotect()ed
        range on a hugepage VMA is hugepage aligned (yes, really, the sense of
        is_aligned_hugepage_range() is the opposite of what you'd guess :-/).
      
        In fact, we don't need this test.  If the given addresses match the
        beginning/end of a hugepage VMA they must already be suitably aligned.  If
        they don't, then mprotect_fixup() will attempt to split the VMA.  The very
        first test in split_vma() will check for a badly aligned address on a
        hugepage VMA and return -EINVAL if necessary.
      
      From: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
      
        On i386 and x86-64, pte flag _PAGE_PSE collides with _PAGE_PROTNONE.  The
        identify of hugetlb pte is lost when changing page protection via mprotect.
        A page fault occurs later will trigger a bug check in huge_pte_alloc().
      
        The fix is to always make new pte a hugetlb pte and also to clean up
        legacy code where _PAGE_PRESENT is forced on in the pre-faulting day.
      Signed-off-by: default avatarZhang Yanmin <yanmin.zhang@intel.com>
      Cc: David Gibson <david@gibson.dropbear.id.au>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Signed-off-by: default avatarKen Chen <kenneth.w.chen@intel.com>
      Signed-off-by: default avatarNishanth Aravamudan <nacc@us.ibm.com>
      Cc: Andi Kleen <ak@muc.de>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8f860591
  15. 06 Jan, 2006 1 commit
  16. 13 Nov, 2005 1 commit
    • Robin Holt's avatar
      [PATCH] mm: ZAP_BLOCK causes redundant work · 51c6f666
      Robin Holt authored
      The address based work estimate for unmapping (for lockbreak) is and always
      was horribly inefficient for sparse mappings.  The problem is most simply
      explained with an example:
      
      If we find a pgd is clear, we still have to call into unmap_page_range
      PGDIR_SIZE / ZAP_BLOCK_SIZE times, each time checking the clear pgd, in
      order to progress the working address to the next pgd.
      
      The fundamental way to solve the problem is to keep track of the end
      address we've processed and pass it back to the higher layers.
      
      From: Nick Piggin <npiggin@suse.de>
      
        Modification to completely get away from address based work estimate
        and instead use an abstract count, with a very small cost for empty
        entries as opposed to present pages.
      
        On 2.6.14-git2, ppc64, and CONFIG_PREEMPT=y, mapping and unmapping 1TB
        of virtual address space takes 1.69s; with the following patch applied,
        this operation can be done 1000 times in less than 0.01s
      
      From: Andrew Morton <akpm@osdl.org>
      
      With CONFIG_HUTETLB_PAGE=n:
      
      mm/memory.c: In function `unmap_vmas':
      mm/memory.c:779: warning: division by zero
      
      Due to
      
      			zap_work -= (end - start) /
      					(HPAGE_SIZE / PAGE_SIZE);
      
      So make the dummy HPAGE_SIZE non-zero
      Signed-off-by: default avatarRobin Holt <holt@sgi.com>
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Cc: Hugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      51c6f666
  17. 29 Oct, 2005 1 commit
    • Hugh Dickins's avatar
      [PATCH] mm: unmap_vmas with inner ptlock · 508034a3
      Hugh Dickins authored
      Remove the page_table_lock from around the calls to unmap_vmas, and replace
      the pte_offset_map in zap_pte_range by pte_offset_map_lock: all callers are
      now safe to descend without page_table_lock.
      
      Don't attempt fancy locking for hugepages, just take page_table_lock in
      unmap_hugepage_range.  Which makes zap_hugepage_range, and the hugetlb test in
      zap_page_range, redundant: unmap_vmas calls unmap_hugepage_range anyway.  Nor
      does unmap_vmas have much use for its mm arg now.
      
      The tlb_start_vma and tlb_end_vma in unmap_page_range are now called without
      page_table_lock: if they're implemented at all, they typically come down to
      flush_cache_range (usually done outside page_table_lock) and flush_tlb_range
      (which we already audited for the mprotect case).
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      508034a3
  18. 20 Oct, 2005 1 commit
  19. 19 Oct, 2005 1 commit
    • Seth, Rohit's avatar
      [PATCH] Handle spurious page fault for hugetlb region · 3359b54c
      Seth, Rohit authored
      The hugetlb pages are currently pre-faulted.  At the time of mmap of
      hugepages, we populate the new PTEs.  It is possible that HW has already
      cached some of the unused PTEs internally.  These stale entries never
      get a chance to be purged in existing control flow.
      
      This patch extends the check in page fault code for hugepages.  Check if
      a faulted address falls with in size for the hugetlb file backing it.
      We return VM_FAULT_MINOR for these cases (assuming that the arch
      specific page-faulting code purges the stale entry for the archs that
      need it).
      Signed-off-by: default avatarRohit Seth <rohit.seth@intel.com>
      
      [ This is apparently arguably an ia64 port bug. But the code won't
        hurt, and for now it fixes a real problem on some ia64 machines ]
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      3359b54c
  20. 05 Sep, 2005 1 commit
    • Chen, Kenneth W's avatar
      [PATCH] remove hugetlb_clean_stale_pgtable() and fix huge_pte_alloc() · 0e5c9f39
      Chen, Kenneth W authored
      I don't think we need to call hugetlb_clean_stale_pgtable() anymore
      in 2.6.13 because of the rework with free_pgtables().  It now collect
      all the pte page at the time of munmap.  It used to only collect page
      table pages when entire one pgd can be freed and left with staled pte
      pages.  Not anymore with 2.6.13.  This function will never be called
      and We should turn it into a BUG_ON.
      
      I also spotted two problems here, not Adam's fault :-)
      (1) in huge_pte_alloc(), it looks like a bug to me that pud is not
          checked before calling pmd_alloc()
      (2) in hugetlb_clean_stale_pgtable(), it also missed a call to
          pmd_free_tlb.  I think a tlb flush is required to flush the mapping
          for the page table itself when we clear out the pmd pointing to a
          pte page.  However, since hugetlb_clean_stale_pgtable() is never
          called, so it won't trigger the bug.
      Signed-off-by: default avatarKen Chen <kenneth.w.chen@intel.com>
      Cc: Adam Litke <agl@us.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      0e5c9f39
  21. 21 Jun, 2005 1 commit
    • David Gibson's avatar
      [PATCH] Hugepage consolidation · 63551ae0
      David Gibson authored
      A lot of the code in arch/*/mm/hugetlbpage.c is quite similar.  This patch
      attempts to consolidate a lot of the code across the arch's, putting the
      combined version in mm/hugetlb.c.  There are a couple of uglyish hacks in
      order to covert all the hugepage archs, but the result is a very large
      reduction in the total amount of code.  It also means things like hugepage
      lazy allocation could be implemented in one place, instead of six.
      
      Tested, at least a little, on ppc64, i386 and x86_64.
      
      Notes:
      	- this patch changes the meaning of set_huge_pte() to be more
      	  analagous to set_pte()
      	- does SH4 need s special huge_ptep_get_and_clear()??
      Acked-by: default avatarWilliam Lee Irwin <wli@holomorphy.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      63551ae0
  22. 19 Apr, 2005 1 commit
    • Hugh Dickins's avatar
      [PATCH] freepgt: hugetlb_free_pgd_range · 3bf5ee95
      Hugh Dickins authored
      ia64 and ppc64 had hugetlb_free_pgtables functions which were no longer being
      called, and it wasn't obvious what to do about them.
      
      The ppc64 case turns out to be easy: the associated tables are noted elsewhere
      and freed later, safe to either skip its hugetlb areas or go through the
      motions of freeing nothing.  Since ia64 does need a special case, restore to
      ppc64 the special case of skipping them.
      
      The ia64 hugetlb case has been broken since pgd_addr_end went in, though it
      probably appeared to work okay if you just had one such area; in fact it's
      been broken much longer if you consider a long munmap spanning from another
      region into the hugetlb region.
      
      In the ia64 hugetlb region, more virtual address bits are available than in
      the other regions, yet the page tables are structured the same way: the page
      at the bottom is larger.  Here we need to scale down each addr before passing
      it to the standard free_pgd_range.  Was about to write a hugely_scaled_down
      macro, but found htlbpage_to_page already exists for just this purpose.  Fixed
      off-by-one in ia64 is_hugepage_only_range.
      
      Uninline free_pgd_range to make it available to ia64.  Make sure the
      vma-gathering loop in free_pgtables cannot join a hugepage_only_range to any
      other (safe to join huges?  probably but don't bother).
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      3bf5ee95
  23. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4