drivers/staging/zcache/TODO

   1
   2 ** ZCACHE PLAN FOR PROMOTION FROM STAGING **
   3
   4 Last updated: Feb 13, 2013
   5
   6 PLAN STEPS
   7
   8 1. merge zcache and ramster to eliminate horrible code duplication
   9 2. converge on a predictable, writeback-capable allocator
  10 3. use debugfs instead of sysfs (per akpm feedback in 2011)
  11 4. zcache side of cleancache/mm WasActive patch
  12 5. zcache side of frontswap exclusive gets
  13 6. zcache must be able to writeback to physical swap disk
  14     (per Andrea Arcangeli feedback in 2011)
  15 7. implement adequate policy for writeback
  16 8. frontswap/cleancache work to allow zcache to be loaded
  17     as a module
  18 9. get core mm developer to review
  19 10. incorporate feedback from review
  20 11. get review/acks from 1-2 additional mm developers
  21 12. incorporate any feedback from additional mm reviews
  22 13. propose location/file-naming in mm tree
  23 14. repeat 9-13 as necessary until akpm is happy and merges
  24
  25 STATUS/OWNERSHIP
  26
  27 1. DONE as part of "new" zcache; in staging/zcache for 3.9
  28 2. DONE as part of "new" zcache (cf zbud.[ch]); in staging/zcache for 3.9
  29     (this was the core of the zcache1 vs zcache2 flail)
  30 3. DONE as part of "new" zcache; in staging/zcache for 3.9
  31 4. DONE (w/caveats) as part of "new" zcache; per cleancache performance
  32     feedback see https://lkml.org/lkml/2011/8/17/351, in
  33     staging/zcache for 3.9; dependent on proposed mm patch, see
  34     https://lkml.org/lkml/2012/1/25/300
  35 5. DONE as part of "new" zcache; performance tuning only,
  36     in staging/zcache for 3.9; dependent on frontswap patch
  37     merged in 3.7 (33c2a174)
  38 6. DONE (w/caveats), prototyped as part of "new" zcache, had
  39     bad memory leak; reimplemented to use sjennings clever tricks
  40     and proposed mm patches with new version in staging/zcache
  41     for 3.9, see https://lkml.org/lkml/2013/2/6/437;
  42 7. PROTOTYPED as part of "new" zcache; in staging/zcache for 3.9;
  43     needs more review (plan to discuss at LSF/MM 2013)
  44 8. IN PROGRESS; owned by Konrad Wilk; v2 recently posted
  45    http://lkml.org/lkml/2013/2/1/542
  46 9. IN PROGRESS; owned by Konrad Wilk; Mel Gorman provided
  47    great feedback in August 2012 (unfortunately of "old"
  48    zcache)
  49 10. Konrad posted series of fixes (that now need rebasing)
  50     https://lkml.org/lkml/2013/2/1/566
  51 11. NOT DONE; owned by Konrad Wilk
  52 12. TBD (depends on quantity of feedback)
  53 13. PROPOSED; one suggestion proposed by Dan; needs more ideas/feedback
  54 14. TBD (depends on feedback)
  55
  56 WHO NEEDS TO AGREE
  57
  58 Not sure.  Seth Jennings is now pursuing a separate but semi-parallel
  59 track.  Akpm clearly has to approve for any mm merge to happen.  Minchan
  60 Kim has interest but may be happy if/when zram is merged into mm.  Konrad
  61 Wilk may be maintainer if akpm decides compression is maintainable
  62 separately from the rest of mm.  (More LSF/MM 2013 discussion.)
  63
  64 ZCACHE FUTURE NEW FUNCTIONALITY
  65
  66 A. Support zsmalloc as an alternative high-density allocator
  67     (See https://lkml.org/lkml/2013/1/23/511)
  68 B. Support zero-filled pages more efficiently
  69 C. Possibly support three zbuds per pageframe when space allows