This patch set moves zram from crypto API to a custom compression API which allows us to tune and configure compression algorithms, something that crypto API, unfortunately, doesn't support. Basically, this seroes brings back the bits of comp "backend" code that we had many years ago. This means that if we want zram to support new compression algorithms we need to implement corresponding backends. Currently, zram supports a pretty decent number of comp backends: lzo, lzorle, lz4, lz4hc, deflate, zstd At this point we handle 2 parameters: a compression level and a pre-trained compression dictionary. Which seems like a good enough start. The list will be extended in the future. Examples: - changes default compression level echo "algo=zstd level=11" > /sys/block/zram0/comp_algorithm - passes path to a pre-trained dictionary echo "algo=zstd dict=/etc/dictionary" > /sys/block/zram0/comp_algorithm TEST ==== using default zstd /sys/block/zram0/mm_stat 1750315008 504602831 514256896 0 514256896 1 0 34204 34204 using zstd level=7 dict=/etc/dictionary /sys/block/zram0/mm_stat 1750310912 432540606 441712640 0 441712640 1 0 34187 34187 Sergey Senozhatsky (14): zram: move from crypto API to custom comp backends API zram: add lzo and lzorle compression backends support zram: add lz4 compression backend support zram: add lz4hc compression backend support zram: add zstd compression backend support zram: pass estimated src size hint to zstd zram: add zlib compression backend support zram: check that backends array has at least one backend zram: introduce zcomp_config structure zram: extend comp_algorithm attr write handling zram: support compression level comp config zram: add support for dict comp config zram: add dictionary support to zstd backend Documentation/zram: add documentation for algorithm parameters Documentation/admin-guide/blockdev/zram.rst | 38 ++++- drivers/block/zram/Kconfig | 69 ++++++-- drivers/block/zram/Makefile | 7 + drivers/block/zram/backend_deflate.c | 133 +++++++++++++++ drivers/block/zram/backend_deflate.h | 10 ++ drivers/block/zram/backend_lz4.c | 47 ++++++ drivers/block/zram/backend_lz4.h | 10 ++ drivers/block/zram/backend_lz4hc.c | 74 +++++++++ drivers/block/zram/backend_lz4hc.h | 10 ++ drivers/block/zram/backend_lzo.c | 44 +++++ drivers/block/zram/backend_lzo.h | 10 ++ drivers/block/zram/backend_lzorle.c | 44 +++++ drivers/block/zram/backend_lzorle.h | 10 ++ drivers/block/zram/backend_zstd.c | 174 ++++++++++++++++++++ drivers/block/zram/backend_zstd.h | 10 ++ drivers/block/zram/zcomp.c | 145 ++++++++-------- drivers/block/zram/zcomp.h | 38 ++++- drivers/block/zram/zram_drv.c | 110 ++++++++++++- drivers/block/zram/zram_drv.h | 1 + 19 files changed, 870 insertions(+), 114 deletions(-) create mode 100644 drivers/block/zram/backend_deflate.c create mode 100644 drivers/block/zram/backend_deflate.h create mode 100644 drivers/block/zram/backend_lz4.c create mode 100644 drivers/block/zram/backend_lz4.h create mode 100644 drivers/block/zram/backend_lz4hc.c create mode 100644 drivers/block/zram/backend_lz4hc.h create mode 100644 drivers/block/zram/backend_lzo.c create mode 100644 drivers/block/zram/backend_lzo.h create mode 100644 drivers/block/zram/backend_lzorle.c create mode 100644 drivers/block/zram/backend_lzorle.h create mode 100644 drivers/block/zram/backend_zstd.c create mode 100644 drivers/block/zram/backend_zstd.h -- 2.45.0.rc1.225.g2a3ae87e7f-goog
