1. 20 Jan, 2015 1 commit
  2. 15 Dec, 2009 1 commit
  3. 08 Jan, 2009 2 commits
    • Paul Mundt's avatar
      NOMMU: Make mmap allocation page trimming behaviour configurable. · dd8632a1
      Paul Mundt authored
      NOMMU mmap allocates a piece of memory for an mmap that's rounded up in size to
      the nearest power-of-2 number of pages.  Currently it then discards the excess
      pages back to the page allocator, making that memory available for use by other
      things.  This can, however, cause greater amount of fragmentation.
      
      To counter this, a sysctl is added in order to fine-tune the trimming
      behaviour.  The default behaviour remains to trim pages aggressively, while
      this can either be disabled completely or set to a higher page-granular
      watermark in order to have finer-grained control.
      
      vm region vm_top bits taken from an earlier patch by David Howells.
      Signed-off-by: 's avatarPaul Mundt <lethal@linux-sh.org>
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      Tested-by: 's avatarMike Frysinger <vapier.adi@gmail.com>
      dd8632a1
    • David Howells's avatar
      NOMMU: Make VMAs per MM as for MMU-mode linux · 8feae131
      David Howells authored
      Make VMAs per mm_struct as for MMU-mode linux.  This solves two problems:
      
       (1) In SYSV SHM where nattch for a segment does not reflect the number of
           shmat's (and forks) done.
      
       (2) In mmap() where the VMA's vm_mm is set to point to the parent mm by an
           exec'ing process when VM_EXECUTABLE is specified, regardless of the fact
           that a VMA might be shared and already have its vm_mm assigned to another
           process or a dead process.
      
      A new struct (vm_region) is introduced to track a mapped region and to remember
      the circumstances under which it may be shared and the vm_list_struct structure
      is discarded as it's no longer required.
      
      This patch makes the following additional changes:
      
       (1) Regions are now allocated with alloc_pages() rather than kmalloc() and
           with no recourse to __GFP_COMP, so the pages are not composite.  Instead,
           each page has a reference on it held by the region.  Anything else that is
           interested in such a page will have to get a reference on it to retain it.
           When the pages are released due to unmapping, each page is passed to
           put_page() and will be freed when the page usage count reaches zero.
      
       (2) Excess pages are trimmed after an allocation as the allocation must be
           made as a power-of-2 quantity of pages.
      
       (3) VMAs are added to the parent MM's R/B tree and mmap lists.  As an MM may
           end up with overlapping VMAs within the tree, the VMA struct address is
           appended to the sort key.
      
       (4) Non-anonymous VMAs are now added to the backing inode's prio list.
      
       (5) Holes may be punched in anonymous VMAs with munmap(), releasing parts of
           the backing region.  The VMA and region structs will be split if
           necessary.
      
       (6) sys_shmdt() only releases one attachment to a SYSV IPC shared memory
           segment instead of all the attachments at that addresss.  Multiple
           shmat()'s return the same address under NOMMU-mode instead of different
           virtual addresses as under MMU-mode.
      
       (7) Core dumping for ELF-FDPIC requires fewer exceptions for NOMMU-mode.
      
       (8) /proc/maps is now the global list of mapped regions, and may list bits
           that aren't actually mapped anywhere.
      
       (9) /proc/meminfo gains a line (tagged "MmapCopy") that indicates the amount
           of RAM currently allocated by mmap to hold mappable regions that can't be
           mapped directly.  These are copies of the backing device or file if not
           anonymous.
      
      These changes make NOMMU mode more similar to MMU mode.  The downside is that
      NOMMU mode requires some extra memory to track things over NOMMU without this
      patch (VMAs are no longer shared, and there are now region structs).
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      Tested-by: 's avatarMike Frysinger <vapier.adi@gmail.com>
      Acked-by: 's avatarPaul Mundt <lethal@linux-sh.org>
      8feae131
  4. 27 Sep, 2006 4 commits
  5. 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