1. 11 Dec, 2009 1 commit
  2. 22 Sep, 2009 2 commits
  3. 11 Jun, 2009 1 commit
  4. 02 Aug, 2008 1 commit
  5. 15 Feb, 2006 2 commits
    • Michael S. Tsirkin's avatar
      [PATCH] add asm-generic/mman.h · 5f6164f3
      Michael S. Tsirkin authored
      
      
      Make new MADV_REMOVE, MADV_DONTFORK, MADV_DOFORK consistent across all
      arches.  The idea is to make it possible to use them portably even before
      distros include them in libc headers.
      
      Move common flags to asm-generic/mman.h
      Signed-off-by: default avatarMichael S. Tsirkin <mst@mellanox.co.il>
      Cc: Roland Dreier <rolandd@cisco.com>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      5f6164f3
    • Michael S. Tsirkin's avatar
      [PATCH] madvise MADV_DONTFORK/MADV_DOFORK · f8225661
      Michael S. Tsirkin authored
      
      
      Currently, copy-on-write may change the physical address of a page even if the
      user requested that the page is pinned in memory (either by mlock or by
      get_user_pages).  This happens if the process forks meanwhile, and the parent
      writes to that page.  As a result, the page is orphaned: in case of
      get_user_pages, the application will never see any data hardware DMA's into
      this page after the COW.  In case of mlock'd memory, the parent is not getting
      the realtime/security benefits of mlock.
      
      In particular, this affects the Infiniband modules which do DMA from and into
      user pages all the time.
      
      This patch adds madvise options to control whether memory range is inherited
      across fork.  Useful e.g.  for when hardware is doing DMA from/into these
      pages.  Could also be useful to an application wanting to speed up its forks
      by cutting large areas out of consideration.
      Signed-off-by: default avatarMichael S. Tsirkin <mst@mellanox.co.il>
      Acked-by: default avatarHugh Dickins <hugh@veritas.com>
      Cc: Michael Kerrisk <mtk-manpages@gmx.net>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f8225661
  6. 06 Jan, 2006 1 commit
    • Badari Pulavarty's avatar
      [PATCH] madvise(MADV_REMOVE): remove pages from tmpfs shm backing store · f6b3ec23
      Badari Pulavarty authored
      
      
      Here is the patch to implement madvise(MADV_REMOVE) - which frees up a
      given range of pages & its associated backing store.  Current
      implementation supports only shmfs/tmpfs and other filesystems return
      -ENOSYS.
      
      "Some app allocates large tmpfs files, then when some task quits and some
      client disconnect, some memory can be released.  However the only way to
      release tmpfs-swap is to MADV_REMOVE". - Andrea Arcangeli
      
      Databases want to use this feature to drop a section of their bufferpool
      (shared memory segments) - without writing back to disk/swap space.
      
      This feature is also useful for supporting hot-plug memory on UML.
      
      Concerns raised by Andrew Morton:
      
      - "We have no plan for holepunching!  If we _do_ have such a plan (or
        might in the future) then what would the API look like?  I think
        sys_holepunch(fd, start, len), so we should start out with that."
      
      - Using madvise is very weird, because people will ask "why do I need to
        mmap my file before I can stick a hole in it?"
      
      - None of the other madvise operations call into the filesystem in this
        manner.  A broad question is: is this capability an MM operation or a
        filesytem operation?  truncate, for example, is a filesystem operation
        which sometimes has MM side-effects.  madvise is an mm operation and with
        this patch, it gains FS side-effects, only they're really, really
        significant ones."
      
      Comments:
      
      - Andrea suggested the fs operation too but then it's more efficient to
        have it as a mm operation with fs side effects, because they don't
        immediatly know fd and physical offset of the range.  It's possible to
        fixup in userland and to use the fs operation but it's more expensive,
        the vmas are already in the kernel and we can use them.
      
      Short term plan &  Future Direction:
      
      - We seem to need this interface only for shmfs/tmpfs files in the short
        term.  We have to add hooks into the filesystem for correctness and
        completeness.  This is what this patch does.
      
      - In the future, plan is to support both fs and mmap apis also.  This
        also involves (other) filesystem specific functions to be implemented.
      
      - Current patch doesn't support VM_NONLINEAR - which can be addressed in
        the future.
      Signed-off-by: default avatarBadari Pulavarty <pbadari@us.ibm.com>
      Cc: Hugh Dickins <hugh@veritas.com>
      Cc: Andrea Arcangeli <andrea@suse.de>
      Cc: Michael Kerrisk <mtk-manpages@gmx.net>
      Cc: Ulrich Drepper <drepper@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f6b3ec23
  7. 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