1. 21 Aug, 2012 1 commit
    • Michal Hocko's avatar
      mm: hugetlbfs: correctly populate shared pmd · eb48c071
      Michal Hocko authored
      
      
      Each page mapped in a process's address space must be correctly
      accounted for in _mapcount.  Normally the rules for this are
      straightforward but hugetlbfs page table sharing is different.  The page
      table pages at the PMD level are reference counted while the mapcount
      remains the same.
      
      If this accounting is wrong, it causes bugs like this one reported by
      Larry Woodman:
      
        kernel BUG at mm/filemap.c:135!
        invalid opcode: 0000 [#1] SMP
        CPU 22
        Modules linked in: bridge stp llc sunrpc binfmt_misc dcdbas microcode pcspkr acpi_pad acpi]
        Pid: 18001, comm: mpitest Tainted: G        W    3.3.0+ #4 Dell Inc. PowerEdge R620/07NDJ2
        RIP: 0010:[<ffffffff8112cfed>]  [<ffffffff8112cfed>] __delete_from_page_cache+0x15d/0x170
        Process mpitest (pid: 18001, threadinfo ffff880428972000, task ffff880428b5cc20)
        Call Trace:
          delete_from_page_cache+0x40/0x80
          truncate_hugepages+0x115/0x1f0
          hugetlbfs_evict_inode+0x18/0x30
          evict+0x9f/0x1b0
          iput_final+0xe3/0x1e0
          iput+0x3e/0x50
          d_kill+0xf8/0x110
          dput+0xe2/0x1b0
          __fput+0x162/0x240
      
      During fork(), copy_hugetlb_page_range() detects if huge_pte_alloc()
      shared page tables with the check dst_pte == src_pte.  The logic is if
      the PMD page is the same, they must be shared.  This assumes that the
      sharing is between the parent and child.  However, if the sharing is
      with a different process entirely then this check fails as in this
      diagram:
      
        parent
          |
          ------------>pmd
                       src_pte----------> data page
                                              ^
        other--------->pmd--------------------|
                        ^
        child-----------|
                       dst_pte
      
      For this situation to occur, it must be possible for Parent and Other to
      have faulted and failed to share page tables with each other.  This is
      possible due to the following style of race.
      
        PROC A                                          PROC B
        copy_hugetlb_page_range                         copy_hugetlb_page_range
          src_pte == huge_pte_offset                      src_pte == huge_pte_offset
          !src_pte so no sharing                          !src_pte so no sharing
      
        (time passes)
      
        hugetlb_fault                                   hugetlb_fault
          huge_pte_alloc                                  huge_pte_alloc
            huge_pmd_share                                 huge_pmd_share
              LOCK(i_mmap_mutex)
              find nothing, no sharing
              UNLOCK(i_mmap_mutex)
                                                            LOCK(i_mmap_mutex)
                                                            find nothing, no sharing
                                                            UNLOCK(i_mmap_mutex)
            pmd_alloc                                       pmd_alloc
            LOCK(instantiation_mutex)
            fault
            UNLOCK(instantiation_mutex)
                                                        LOCK(instantiation_mutex)
                                                        fault
                                                        UNLOCK(instantiation_mutex)
      
      These two processes are not poing to the same data page but are not
      sharing page tables because the opportunity was missed.  When either
      process later forks, the src_pte == dst pte is potentially insufficient.
      As the check falls through, the wrong PTE information is copied in
      (harmless but wrong) and the mapcount is bumped for a page mapped by a
      shared page table leading to the BUG_ON.
      
      This patch addresses the issue by moving pmd_alloc into huge_pmd_share
      which guarantees that the shared pud is populated in the same critical
      section as pmd.  This also means that huge_pte_offset test in
      huge_pmd_share is serialized correctly now which in turn means that the
      success of the sharing will be higher as the racing tasks see the pud
      and pmd populated together.
      
      Race identified and changelog written mostly by Mel Gorman.
      
      {akpm@linux-foundation.org: attempt to make the huge_pmd_share() comment comprehensible, clean up coding style]
      Reported-by: default avatarLarry Woodman <lwoodman@redhat.com>
      Tested-by: default avatarLarry Woodman <lwoodman@redhat.com>
      Reviewed-by: default avatarMel Gorman <mgorman@suse.de>
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.cz>
      Reviewed-by: default avatarRik van Riel <riel@redhat.com>
      Cc: David Gibson <david@gibson.dropbear.id.au>
      Cc: Ken Chen <kenchen@google.com>
      Cc: Cong Wang <xiyou.wangcong@gmail.com>
      Cc: Hillf Danton <dhillf@gmail.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      eb48c071
  2. 22 Mar, 2012 2 commits
  3. 07 Mar, 2012 2 commits
    • Linus Torvalds's avatar
      x86: fix typo in recent find_vma_prev purge · 55062d06
      Linus Torvalds authored
      
      
      It turns out that test-compiling this file on x86-64 doesn't really
      help, because much of it is x86-32-specific.  And so I hadn't noticed
      the slightly over-eager removal of the 'r' from 'addr' variable despite
      thinking I had tested it.
      Signed-off-by: default avatarLinus "oopsie" Torvalds <torvalds@linux-foundation.org>
      55062d06
    • Linus Torvalds's avatar
      vm: avoid using find_vma_prev() unnecessarily · 097d5910
      Linus Torvalds authored
      Several users of "find_vma_prev()" were not in fact interested in the
      previous vma if there was no primary vma to be found either.  And in
      those cases, we're much better off just using the regular "find_vma()",
      and then "prev" can be looked up by just checking vma->vm_prev.
      
      The find_vma_prev() semantics are fairly subtle (see Mikulas' recent
      commit 83cd904d
      
      : "mm: fix find_vma_prev"), and the whole "return
      prev by reference" means that it generates worse code too.
      
      Thus this "let's avoid using this inconvenient and clearly too subtle
      interface when we don't really have to" patch.
      
      Cc: Mikulas Patocka <mpatocka@redhat.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      097d5910
  4. 25 May, 2011 1 commit
  5. 18 Mar, 2011 1 commit
  6. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  7. 29 May, 2009 1 commit
    • Mel Gorman's avatar
      x86: ignore VM_LOCKED when determining if hugetlb-backed page tables can be shared or not · 32b154c0
      Mel Gorman authored
      Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13302
      
      
      
      On x86 and x86-64, it is possible that page tables are shared beween
      shared mappings backed by hugetlbfs.  As part of this,
      page_table_shareable() checks a pair of vma->vm_flags and they must match
      if they are to be shared.  All VMA flags are taken into account, including
      VM_LOCKED.
      
      The problem is that VM_LOCKED is cleared on fork().  When a process with a
      shared memory segment forks() to exec() a helper, there will be shared
      VMAs with different flags.  The impact is that the shared segment is
      sometimes considered shareable and other times not, depending on what
      process is checking.
      
      What happens is that the segment page tables are being shared but the
      count is inaccurate depending on the ordering of events.  As the page
      tables are freed with put_page(), bad pmd's are found when some of the
      children exit.  The hugepage counters also get corrupted and the Total and
      Free count will no longer match even when all the hugepage-backed regions
      are freed.  This requires a reboot of the machine to "fix".
      
      This patch addresses the problem by comparing all flags except VM_LOCKED
      when deciding if pagetables should be shared or not for hugetlbfs-backed
      mapping.
      Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
      Acked-by: default avatarHugh Dickins <hugh.dickins@tiscali.co.uk>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: <stable@kernel.org>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: <starlight@binnacle.cx>
      Cc: Eric B Munson <ebmunson@us.ibm.com>
      Cc: Adam Litke <agl@us.ibm.com>
      Cc: Andy Whitcroft <apw@canonical.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      32b154c0
  8. 24 Jul, 2008 4 commits
  9. 27 Mar, 2008 1 commit
  10. 30 Jan, 2008 1 commit
    • Jeremy Fitzhardinge's avatar
      x86: demacro asm-x86/pgalloc_32.h · a5a19c63
      Jeremy Fitzhardinge authored
      
      
      Convert macros into inline functions, for better type-checking.
      
      This patch required a little bit of fiddling with headers in order to
      make __(pte|pmd)_free_tlb inline rather than macros.
      asm-generic/tlb.h includes asm/pgalloc.h, though it doesn't directly
      use any pgalloc definitions.  I removed this include to avoid an
      include cycle, but it may cause secondary compile failures by things
      depending on the indirect inclusion; arch/x86/mm/hugetlbpage.c was one
      such place; there may be others.
      Signed-off-by: default avatarJeremy Fitzhardinge <jeremy@xensource.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      a5a19c63
  11. 11 Oct, 2007 1 commit
  12. 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
  13. 08 May, 2007 1 commit
  14. 07 May, 2007 1 commit
  15. 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
  16. 30 Jun, 2006 1 commit
  17. 22 Mar, 2006 1 commit
    • 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
  18. 05 Sep, 2005 3 commits
    • 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
    • Adam Litke's avatar
      [PATCH] hugetlb: check p?d_present in huge_pte_offset() · 02b0ccef
      Adam Litke authored
      
      
      For demand faulting, we cannot assume that the page tables will be
      populated.  Do what the rest of the architectures do and test p?d_present()
      while walking down the page table.
      Signed-off-by: default avatarAdam Litke <agl@us.ibm.com>
      Cc: <linux-mm@kvack.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      02b0ccef
    • Adam Litke's avatar
      [PATCH] hugetlb: move stale pte check into huge_pte_alloc() · 7bf07f3d
      Adam Litke authored
      Initial Post (Wed, 17 Aug 2005)
      
      This patch moves the
      	if (! pte_none(*pte))
      		hugetlb_clean_stale_pgtable(pte);
      logic into huge_pte_alloc() so all of its callers can be immune to the bug
      described by Kenneth Chen at http://lkml.org/lkml/2004/6/16/246
      
      
      
      > It turns out there is a bug in hugetlb_prefault(): with 3 level page table,
      > huge_pte_alloc() might return a pmd that points to a PTE page. It happens
      > if the virtual address for hugetlb mmap is recycled from previously used
      > normal page mmap. free_pgtables() might not scrub the pmd entry on
      > munmap and hugetlb_prefault skips on any pmd presence regardless what type
      > it is.
      
      Unless I am missing something, it seems more correct to place the check inside
      huge_pte_alloc() to prevent a the same bug wherever a huge pte is allocated.
      It also allows checking for this condition when lazily faulting huge pages
      later in the series.
      Signed-off-by: default avatarAdam Litke <agl@us.ibm.com>
      Cc: <linux-mm@kvack.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      7bf07f3d
  19. 22 Jun, 2005 2 commits
    • Wolfgang Wander's avatar
      [PATCH] Avoiding mmap fragmentation · 1363c3cd
      Wolfgang Wander authored
      
      
      Ingo recently introduced a great speedup for allocating new mmaps using the
      free_area_cache pointer which boosts the specweb SSL benchmark by 4-5% and
      causes huge performance increases in thread creation.
      
      The downside of this patch is that it does lead to fragmentation in the
      mmap-ed areas (visible via /proc/self/maps), such that some applications
      that work fine under 2.4 kernels quickly run out of memory on any 2.6
      kernel.
      
      The problem is twofold:
      
        1) the free_area_cache is used to continue a search for memory where
           the last search ended.  Before the change new areas were always
           searched from the base address on.
      
           So now new small areas are cluttering holes of all sizes
           throughout the whole mmap-able region whereas before small holes
           tended to close holes near the base leaving holes far from the base
           large and available for larger requests.
      
        2) the free_area_cache also is set to the location of the last
           munmap-ed area so in scenarios where we allocate e.g.  five regions of
           1K each, then free regions 4 2 3 in this order the next request for 1K
           will be placed in the position of the old region 3, whereas before we
           appended it to the still active region 1, placing it at the location
           of the old region 2.  Before we had 1 free region of 2K, now we only
           get two free regions of 1K -> fragmentation.
      
      The patch addresses thes issues by introducing yet another cache descriptor
      cached_hole_size that contains the largest known hole size below the
      current free_area_cache.  If a new request comes in the size is compared
      against the cached_hole_size and if the request can be filled with a hole
      below free_area_cache the search is started from the base instead.
      
      The results look promising: Whereas 2.6.12-rc4 fragments quickly and my
      (earlier posted) leakme.c test program terminates after 50000+ iterations
      with 96 distinct and fragmented maps in /proc/self/maps it performs nicely
      (as expected) with thread creation, Ingo's test_str02 with 20000 threads
      requires 0.7s system time.
      
      Taking out Ingo's patch (un-patch available per request) by basically
      deleting all mentions of free_area_cache from the kernel and starting the
      search for new memory always at the respective bases we observe: leakme
      terminates successfully with 11 distinctive hardly fragmented areas in
      /proc/self/maps but thread creating is gringdingly slow: 30+s(!) system
      time for Ingo's test_str02 with 20000 threads.
      
      Now - drumroll ;-) the appended patch works fine with leakme: it ends with
      only 7 distinct areas in /proc/self/maps and also thread creation seems
      sufficiently fast with 0.71s for 20000 threads.
      Signed-off-by: default avatarWolfgang Wander <wwc@rentec.com>
      Credit-to: "Richard Purdie" <rpurdie@rpsys.net>
      Signed-off-by: default avatarKen Chen <kenneth.w.chen@intel.com>
      Acked-by: Ingo Molnar <mingo@elte.hu> (partly)
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      1363c3cd
    • 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
  20. 19 Apr, 2005 1 commit
  21. 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