[PATCHv3,0/9] zsmalloc/zram: configurable zspage size

Message

Sergey Senozhatsky Oct. 27, 2022, 4:26 a.m. UTC

Hello,

	Some use-cases and/or data patterns may benefit from
larger zspages. Currently the limit on the number of physical
pages that are linked into a zspage is hardcoded to 4. Higher
limit changes key characteristics of a number of the size
classes, improving compactness of the pool and redusing the
amount of memory zsmalloc pool uses. More on this in 0001
commit message.

v3:
-- Removed lots of text from 0001 commit message. Now it's shorter
   and simpler.

v2:
-- Cherry picked a patch from Alexey (minor code tweaks to move
   it ahead of this series)
-- zsmalloc does not require anymore pages-per-zspage limit to be a
   pow of 2 value, and overall doesn't use "order" any longer
-- zram does not require "zspage order" (pow of 2) value anymore
   and instead accepts an integer in [1,16] range
-- There is no global huge_class_size in zsmalloc anymore.
   huge_class_size is per-pool, since it depends on pager-per-zspage,
   which can be different for different pools.
-- There is no global huge_class_size in zram anymore. It should
   be per-pool (per-device).
-- Updated documentation
-- Fixed documentation htmldocs warning (Stephen)
-- Dropped get_pages_per_zspage() patch
-- Renamed zram sysfs knob (device attribute)
-- Re-worked "synthetic test" section in the first commit: more numbers,
   objects distribution analysis, etc.



Alexey Romanov (1):
  zram: add size class equals check into recompression

Sergey Senozhatsky (8):
  zsmalloc: turn zspage order into runtime variable
  zsmalloc: move away from page order defines
  zsmalloc: make huge class watermark zs_pool member
  zram: huge size watermark cannot be global
  zsmalloc: pass limit on pages per-zspage to zs_create_pool()
  zram: add pages_per_pool_page device attribute
  Documentation: document zram pages_per_pool_page attribute
  zsmalloc: break out of loop when found perfect zspage order

 Documentation/admin-guide/blockdev/zram.rst |  38 +++++--
 drivers/block/zram/zram_drv.c               |  63 +++++++++--
 drivers/block/zram/zram_drv.h               |   7 ++
 include/linux/zsmalloc.h                    |  14 ++-
 mm/zsmalloc.c                               | 114 +++++++++++++-------
 5 files changed, 178 insertions(+), 58 deletions(-)