1. 08 1月, 2009 1 次提交
    • D
      NOMMU: Make VMAs per MM as for MMU-mode linux · 8feae131
      David Howells 提交于
      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: NDavid Howells <dhowells@redhat.com>
      Tested-by: NMike Frysinger <vapier.adi@gmail.com>
      Acked-by: NPaul Mundt <lethal@linux-sh.org>
      8feae131
  2. 07 1月, 2009 2 次提交
  3. 01 1月, 2009 1 次提交
  4. 20 10月, 2008 1 次提交
    • M
      container freezer: add TIF_FREEZE flag to all architectures · 83224b08
      Matt Helsley 提交于
      This patch series introduces a cgroup subsystem that utilizes the swsusp
      freezer to freeze a group of tasks.  It's immediately useful for batch job
      management scripts.  It should also be useful in the future for
      implementing container checkpoint/restart.
      
      The freezer subsystem in the container filesystem defines a cgroup file
      named freezer.state.  Reading freezer.state will return the current state
      of the cgroup.  Writing "FROZEN" to the state file will freeze all tasks
      in the cgroup.  Subsequently writing "RUNNING" will unfreeze the tasks in
      the cgroup.
      
      * Examples of usage :
      
         # mkdir /containers/freezer
         # mount -t cgroup -ofreezer freezer  /containers
         # mkdir /containers/0
         # echo $some_pid > /containers/0/tasks
      
      to get status of the freezer subsystem :
      
         # cat /containers/0/freezer.state
         RUNNING
      
      to freeze all tasks in the container :
      
         # echo FROZEN > /containers/0/freezer.state
         # cat /containers/0/freezer.state
         FREEZING
         # cat /containers/0/freezer.state
         FROZEN
      
      to unfreeze all tasks in the container :
      
         # echo RUNNING > /containers/0/freezer.state
         # cat /containers/0/freezer.state
         RUNNING
      
      This patch:
      
      The first step in making the refrigerator() available to all
      architectures, even for those without power management.
      
      The purpose of such a change is to be able to use the refrigerator() in a
      new control group subsystem which will implement a control group freezer.
      
      [akpm@linux-foundation.org: fix sparc]
      Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
      Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
      Acked-by: NPavel Machek <pavel@suse.cz>
      Acked-by: NSerge E. Hallyn <serue@us.ibm.com>
      Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
      Acked-by: NNigel Cunningham <nigel@tuxonice.net>
      Tested-by: NMatt Helsley <matthltc@us.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      83224b08
  5. 16 10月, 2008 1 次提交
  6. 07 9月, 2008 1 次提交
  7. 12 8月, 2008 1 次提交
  8. 07 8月, 2008 1 次提交