From: Rui Salvaterra <rsalvaterra@xxxxxxxxx> Subject: zram: break the strict dependency from lzo >From the beginning, the zram block device always enabled CRYPTO_LZO, since lzo-rle is hardcoded as the fallback compression algorithm. As a consequence, on systems where another compression algorithm is chosen (e.g. CRYPTO_ZSTD), the lzo kernel module becomes unused, while still having to be built/loaded. This patch removes the hardcoded lzo-rle dependency and allows the user to select the default compression algorithm for zram at build time. The previous behaviour is kept, as the default algorithm is still lzo-rle. Link: https://lkml.kernel.org/r/20201207121245.50529-1-rsalvaterra@xxxxxxxxx Signed-off-by: Rui Salvaterra <rsalvaterra@xxxxxxxxx> Suggested-by: Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx> Suggested-by: Minchan Kim <minchan@xxxxxxxxxx> Acked-by: Minchan Kim <minchan@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/block/zram/Kconfig | 42 +++++++++++++++++++++++++++++++- drivers/block/zram/zcomp.c | 2 + drivers/block/zram/zram_drv.c | 2 - 3 files changed, 44 insertions(+), 2 deletions(-) --- a/drivers/block/zram/Kconfig~zram-break-the-strict-dependency-from-lzo +++ a/drivers/block/zram/Kconfig @@ -2,7 +2,7 @@ config ZRAM tristate "Compressed RAM block device support" depends on BLOCK && SYSFS && ZSMALLOC && CRYPTO - select CRYPTO_LZO + depends on CRYPTO_LZO || CRYPTO_ZSTD || CRYPTO_LZ4 || CRYPTO_LZ4HC || CRYPTO_842 help Creates virtual block devices called /dev/zramX (X = 0, 1, ...). Pages written to these disks are compressed and stored in memory @@ -14,6 +14,46 @@ config ZRAM See Documentation/admin-guide/blockdev/zram.rst for more information. +choice + prompt "Default zram compressor" + default ZRAM_DEF_COMP_LZORLE + depends on ZRAM + +config ZRAM_DEF_COMP_LZORLE + bool "lzo-rle" + depends on CRYPTO_LZO + +config ZRAM_DEF_COMP_ZSTD + bool "zstd" + depends on CRYPTO_ZSTD + +config ZRAM_DEF_COMP_LZ4 + bool "lz4" + depends on CRYPTO_LZ4 + +config ZRAM_DEF_COMP_LZO + bool "lzo" + depends on CRYPTO_LZO + +config ZRAM_DEF_COMP_LZ4HC + bool "lz4hc" + depends on CRYPTO_LZ4HC + +config ZRAM_DEF_COMP_842 + bool "842" + depends on CRYPTO_842 + +endchoice + +config ZRAM_DEF_COMP + string + default "lzo-rle" if ZRAM_DEF_COMP_LZORLE + default "zstd" if ZRAM_DEF_COMP_ZSTD + default "lz4" if ZRAM_DEF_COMP_LZ4 + default "lzo" if ZRAM_DEF_COMP_LZO + default "lz4hc" if ZRAM_DEF_COMP_LZ4HC + default "842" if ZRAM_DEF_COMP_842 + config ZRAM_WRITEBACK bool "Write back incompressible or idle page to backing device" depends on ZRAM --- a/drivers/block/zram/zcomp.c~zram-break-the-strict-dependency-from-lzo +++ a/drivers/block/zram/zcomp.c @@ -15,8 +15,10 @@ #include "zcomp.h" static const char * const backends[] = { +#if IS_ENABLED(CONFIG_CRYPTO_LZO) "lzo", "lzo-rle", +#endif #if IS_ENABLED(CONFIG_CRYPTO_LZ4) "lz4", #endif --- a/drivers/block/zram/zram_drv.c~zram-break-the-strict-dependency-from-lzo +++ a/drivers/block/zram/zram_drv.c @@ -42,7 +42,7 @@ static DEFINE_IDR(zram_index_idr); static DEFINE_MUTEX(zram_index_mutex); static int zram_major; -static const char *default_compressor = "lzo-rle"; +static const char *default_compressor = CONFIG_ZRAM_DEF_COMP; /* Module params (documentation at end) */ static unsigned int num_devices = 1; _
