1. 28 5月, 2013 1 次提交
  2. 01 6月, 2012 1 次提交
    • K
      proc: report file/anon bit in /proc/pid/pagemap · 052fb0d6
      Konstantin Khlebnikov 提交于
      This is an implementation of Andrew's proposal to extend the pagemap file
      bits to report what is missing about tasks' working set.
      
      The problem with the working set detection is multilateral.  In the criu
      (checkpoint/restore) project we dump the tasks' memory into image files
      and to do it properly we need to detect which pages inside mappings are
      really in use.  The mincore syscall I though could help with this did not.
       First, it doesn't report swapped pages, thus we cannot find out which
      parts of anonymous mappings to dump.  Next, it does report pages from page
      cache as present even if they are not mapped, and it doesn't make that has
      not been cow-ed.
      
      Note, that issue with swap pages is critical -- we must dump swap pages to
      image file.  But the issues with file pages are optimization -- we can
      take all file pages to image, this would be correct, but if we know that a
      page is not mapped or not cow-ed, we can remove them from dump file.  The
      dump would still be self-consistent, though significantly smaller in size
      (up to 10 times smaller on real apps).
      
      Andrew noticed, that the proc pagemap file solved 2 of 3 above issues --
      it reports whether a page is present or swapped and it doesn't report not
      mapped page cache pages.  But, it doesn't distinguish cow-ed file pages
      from not cow-ed.
      
      I would like to make the last unused bit in this file to report whether the
      page mapped into respective pte is PageAnon or not.
      
      [comment stolen from Pavel Emelyanov's v1 patch]
      Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Matt Mackall <mpm@selenic.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      052fb0d6
  3. 22 3月, 2012 1 次提交
  4. 08 10月, 2009 2 次提交
  5. 17 6月, 2009 2 次提交
  6. 07 6月, 2008 1 次提交