linux/Documentation/vm
Vitaly Wool 9a001fc19c z3fold: the 3-fold allocator for compressed pages
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/2016/5/4/852

Link: http://lkml.kernel.org/r/20160509151753.ec3f9fda3c9898d31ff52a32@gmail.com
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 17:58:30 -07:00
..
.gitignore
00-INDEX mm: introduce idle page tracking 2015-09-10 13:29:01 -07:00
active_mm.txt
balance mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
cleancache.txt cleancache: forbid overriding cleancache_ops 2015-04-14 16:49:03 -07:00
frontswap.txt
highmem.txt
hugetlbpage.txt Documentation: vm: Spelling s/paltform/platform/g 2016-05-14 10:15:10 -06:00
hwpoison.txt mm/memory-failure.c: support use of a dedicated thread to handle SIGBUS(BUS_MCEERR_AO) 2014-06-04 16:54:13 -07:00
idle_page_tracking.txt mm: introduce idle page tracking 2015-09-10 13:29:01 -07:00
ksm.txt
numa
numa_memory_policy.txt Documentation/vm/numa_memory_policy.txt: fix wrong document in numa_memory_policy.txt 2014-04-18 16:40:08 -07:00
overcommit-accounting
page_migration mm: page migration avoid touching newpage until no going back 2015-11-05 19:34:48 -08:00
page_owner.txt mm, page_owner: convert page_owner_inited to static key 2016-03-15 16:55:16 -07:00
pagemap.txt Documentation typo: wrong page flag bit for KPF_HUGE 2016-04-15 15:47:10 -06:00
remap_file_pages.txt mm: replace remap_file_pages() syscall with emulation 2015-02-10 14:30:30 -08:00
slub.txt slub: convert SLAB_DEBUG_FREE to SLAB_CONSISTENCY_CHECKS 2016-03-15 16:55:16 -07:00
soft-dirty.txt
split_page_table_lock mm: make compound_head() robust 2015-11-06 17:50:42 -08:00
transhuge.txt Documentation: vm: fix spelling mistakes 2016-05-20 17:58:30 -07:00
unevictable-lru.txt mm: rmap use pte lock not mmap_sem to set PageMlocked 2015-11-05 19:34:48 -08:00
userfaultfd.txt userfaultfd: change the read API to return a uffd_msg 2015-09-04 16:54:41 -07:00
z3fold.txt z3fold: the 3-fold allocator for compressed pages 2016-05-20 17:58:30 -07:00
zsmalloc.txt zsmalloc: zsmalloc documentation 2015-04-15 16:35:21 -07:00
zswap.txt zswap: update docs for runtime-changeable attributes 2015-09-10 13:29:01 -07:00