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 0002 commit message. v4: -- Fixed type of the max_pages_per_zspage (kbuild reported a "warning: right shift count >= width of type" warning) -- Renamed max_pages_per_zspage variable v3: -- Removed lots of text from 0002 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 | 112 +++++++++++++------- 5 files changed, 176 insertions(+), 58 deletions(-) -- 2.38.1.273.g43a17bfeac-goog
