From: Dan Magenheimer Date: Wed, 13 Feb 2013 18:13:06 +0000 (-0800) Subject: staging: zcache: add TODO file X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=0bcc0429bdb9f7cca3b7ab1f905b0d47031c03e0;p=deliverable%2Flinux.git staging: zcache: add TODO file Add zcache TODO file Signed-off-by: Dan Magenheimer Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/zcache/TODO b/drivers/staging/zcache/TODO new file mode 100644 index 000000000000..c1e26d4973dc --- /dev/null +++ b/drivers/staging/zcache/TODO @@ -0,0 +1,69 @@ + +** ZCACHE PLAN FOR PROMOTION FROM STAGING ** + +Last updated: Feb 13, 2013 + +PLAN STEPS + +1. merge zcache and ramster to eliminate horrible code duplication +2. converge on a predictable, writeback-capable allocator +3. use debugfs instead of sysfs (per akpm feedback in 2011) +4. zcache side of cleancache/mm WasActive patch +5. zcache side of frontswap exclusive gets +6. zcache must be able to writeback to physical swap disk + (per Andrea Arcangeli feedback in 2011) +7. implement adequate policy for writeback +8. frontswap/cleancache work to allow zcache to be loaded + as a module +9. get core mm developer to review +10. incorporate feedback from review +11. get review/acks from 1-2 additional mm developers +12. incorporate any feedback from additional mm reviews +13. propose location/file-naming in mm tree +14. repeat 9-13 as necessary until akpm is happy and merges + +STATUS/OWNERSHIP + +1. DONE as part of "new" zcache; in staging/zcache for 3.9 +2. DONE as part of "new" zcache (cf zbud.[ch]); in staging/zcache for 3.9 + (this was the core of the zcache1 vs zcache2 flail) +3. DONE as part of "new" zcache; in staging/zcache for 3.9 +4. DONE (w/caveats) as part of "new" zcache; per cleancache performance + feedback see https://lkml.org/lkml/2011/8/17/351, in + staging/zcache for 3.9; dependent on proposed mm patch, see + https://lkml.org/lkml/2012/1/25/300 +5. DONE as part of "new" zcache; performance tuning only, + in staging/zcache for 3.9; dependent on frontswap patch + merged in 3.7 (33c2a174) +6. DONE (w/caveats), prototyped as part of "new" zcache, had + bad memory leak; reimplemented to use sjennings clever tricks + and proposed mm patches with new version in staging/zcache + for 3.9, see https://lkml.org/lkml/2013/2/6/437; +7. PROTOTYPED as part of "new" zcache; in staging/zcache for 3.9; + needs more review (plan to discuss at LSF/MM 2013) +8. IN PROGRESS; owned by Konrad Wilk; v2 recently posted + http://lkml.org/lkml/2013/2/1/542 +9. IN PROGRESS; owned by Konrad Wilk; Mel Gorman provided + great feedback in August 2012 (unfortunately of "old" + zcache) +10. Konrad posted series of fixes (that now need rebasing) + https://lkml.org/lkml/2013/2/1/566 +11. NOT DONE; owned by Konrad Wilk +12. TBD (depends on quantity of feedback) +13. PROPOSED; one suggestion proposed by Dan; needs more ideas/feedback +14. TBD (depends on feedback) + +WHO NEEDS TO AGREE + +Not sure. Seth Jennings is now pursuing a separate but semi-parallel +track. Akpm clearly has to approve for any mm merge to happen. Minchan +Kim has interest but may be happy if/when zram is merged into mm. Konrad +Wilk may be maintainer if akpm decides compression is maintainable +separately from the rest of mm. (More LSF/MM 2013 discussion.) + +ZCACHE FUTURE NEW FUNCTIONALITY + +A. Support zsmalloc as an alternative high-density allocator + (See https://lkml.org/lkml/2013/1/23/511) +B. Support zero-filled pages more efficiently +C. Possibly support three zbuds per pageframe when space allows