04 Jun, 2016
1 commit
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Fix erroneous z3fold header access in a HEADLESS page in reclaim
function, and change one remaining direct handle-to-buddy conversion to
use the appropriate helper.Link: http://lkml.kernel.org/r/5748706F.9020208@gmail.com
Signed-off-by: Vitaly Wool
Reviewed-by: Dan Streetman
Cc: Seth Jennings
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 May, 2016
1 commit
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This patch introduces z3fold, a special purpose allocator for storing
compressed pages. It is designed to store up to three compressed pages
per physical page. It is a ZBUD derivative which allows for higher
compression ratio keeping the simplicity and determinism of its
predecessor.This patch comes as a follow-up to the discussions at the Embedded Linux
Conference in San-Diego related to the talk [1]. The outcome of these
discussions was that it would be good to have a compressed page
allocator as stable and deterministic as zbud with with higher
compression ratio.To keep the determinism and simplicity, z3fold, just like zbud, always
stores an integral number of compressed pages per page, but it can store
up to 3 pages unlike zbud which can store at most 2. Therefore the
compression ratio goes to around 2.6x while zbud's one is around 1.7x.The patch is based on the latest linux.git tree.
This version has been updated after testing on various simulators (e.g.
ARM Versatile Express, MIPS Malta, x86_64/Haswell) and basing on
comments from Dan Streetman [3].[1] https://openiotelc2016.sched.org/event/6DAC/swapping-and-embedded-compression-relieves-the-pressure-vitaly-wool-softprise-consulting-ou
[2] https://lkml.org/lkml/2016/4/21/799
[3] https://lkml.org/lkml/2016/5/4/852Link: http://lkml.kernel.org/r/20160509151753.ec3f9fda3c9898d31ff52a32@gmail.com
Signed-off-by: Vitaly Wool
Cc: Seth Jennings
Cc: Dan Streetman
Cc: Vlastimil Babka
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds