Hi Maciej, sorry for jumping in late into this discussion. On Sun, Nov 17, 2019 at 1:05 AM Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx> wrote: <snip> > +config ZSWAP_COMPRESSOR_DEFAULT > + string > + default "deflate" if ZSWAP_COMPRESSOR_DEFAULT_DEFLATE > + default "lzo" if ZSWAP_COMPRESSOR_DEFAULT_LZO > + default "842" if ZSWAP_COMPRESSOR_DEFAULT_842 > + default "lz4" if ZSWAP_COMPRESSOR_DEFAULT_LZ4 > + default "lz4hc" if ZSWAP_COMPRESSOR_DEFAULT_LZ4HC > + default "zstd" if ZSWAP_COMPRESSOR_DEFAULT_ZSTD > + default "" I guess this should also depend on ZSWAP. It looks a bit awkward when this option is present in dotconfig while ZSWAP is not. > + > +choice > + prompt "Compressed cache for swap pages default allocator" > + depends on ZSWAP > + default ZSWAP_ZPOOL_DEFAULT_ZBUD > + help > + Selects the default allocator for the compressed cache for > + swap pages. > + The default is 'zbud' for compatibility, however please do > + read the description of each of the allocators below before > + making a right choice. > + > + The selection made here can be overridden by using the kernel > + command line 'zswap.zpool=' option. > + > +config ZSWAP_ZPOOL_DEFAULT_ZBUD > + bool "zbud" > + select ZBUD > + help > + Use the zbud allocator as the default allocator. > + > +config ZSWAP_ZPOOL_DEFAULT_Z3FOLD > + bool "z3fold" > + select Z3FOLD > + help > + Use the z3fold allocator as the default allocator. > + > +config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC > + bool "zsmalloc" > + select ZSMALLOC > + help > + Use the zsmalloc allocator as the default allocator. > +endchoice > + > +config ZSWAP_ZPOOL_DEFAULT > + string > + default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD > + default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD > + default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC > + default "" Same here. > + > +config ZSWAP_DEFAULT_ON > + bool "Enable the compressed cache for swap pages by default" > + depends on ZSWAP > + help > + If selected, the compressed cache for swap pages will be enabled > + at boot, otherwise it will be disabled. > + > + The selection made here can be overridden by using the kernel > + command line 'zswap.enabled=' option. > + > config ZPOOL > tristate "Common API for compressed memory storage" > help > diff --git a/mm/zswap.c b/mm/zswap.c > index 46a322316e52..71795b6f5b71 100644 > --- a/mm/zswap.c > +++ b/mm/zswap.c > @@ -71,8 +71,12 @@ static u64 zswap_duplicate_entry; > > #define ZSWAP_PARAM_UNSET "" > > -/* Enable/disable zswap (disabled by default) */ > +/* Enable/disable zswap */ > +#ifdef CONFIG_ZSWAP_DEFAULT_ON > +static bool zswap_enabled = true; > +#else > static bool zswap_enabled; > +#endif Wouldn't it be better to have 'static bool zswap_enabled = IS_ENABLED(CONFIG_ZSWAP_DEFAULT_ON);' instead? > static int zswap_enabled_param_set(const char *, > const struct kernel_param *); > static struct kernel_param_ops zswap_enabled_param_ops = { > @@ -82,8 +86,7 @@ static struct kernel_param_ops zswap_enabled_param_ops = { > module_param_cb(enabled, &zswap_enabled_param_ops, &zswap_enabled, 0644); > > /* Crypto compressor to use */ > -#define ZSWAP_COMPRESSOR_DEFAULT "lzo" > -static char *zswap_compressor = ZSWAP_COMPRESSOR_DEFAULT; > +static char *zswap_compressor = CONFIG_ZSWAP_COMPRESSOR_DEFAULT; > static int zswap_compressor_param_set(const char *, > const struct kernel_param *); > static struct kernel_param_ops zswap_compressor_param_ops = { > @@ -95,8 +98,7 @@ module_param_cb(compressor, &zswap_compressor_param_ops, > &zswap_compressor, 0644); > > /* Compressed storage zpool to use */ > -#define ZSWAP_ZPOOL_DEFAULT "zbud" > -static char *zswap_zpool_type = ZSWAP_ZPOOL_DEFAULT; > +static char *zswap_zpool_type = CONFIG_ZSWAP_ZPOOL_DEFAULT; > static int zswap_zpool_param_set(const char *, const struct kernel_param *); > static struct kernel_param_ops zswap_zpool_param_ops = { > .set = zswap_zpool_param_set, > @@ -569,11 +571,12 @@ static __init struct zswap_pool *__zswap_pool_create_fallback(void) > bool has_comp, has_zpool; > > has_comp = crypto_has_comp(zswap_compressor, 0, 0); > - if (!has_comp && strcmp(zswap_compressor, ZSWAP_COMPRESSOR_DEFAULT)) { > + if (!has_comp && strcmp(zswap_compressor, > + CONFIG_ZSWAP_COMPRESSOR_DEFAULT)) { > pr_err("compressor %s not available, using default %s\n", > - zswap_compressor, ZSWAP_COMPRESSOR_DEFAULT); > + zswap_compressor, CONFIG_ZSWAP_COMPRESSOR_DEFAULT); > param_free_charp(&zswap_compressor); > - zswap_compressor = ZSWAP_COMPRESSOR_DEFAULT; > + zswap_compressor = CONFIG_ZSWAP_COMPRESSOR_DEFAULT; > has_comp = crypto_has_comp(zswap_compressor, 0, 0); > } > if (!has_comp) { > @@ -584,11 +587,12 @@ static __init struct zswap_pool *__zswap_pool_create_fallback(void) > } > > has_zpool = zpool_has_pool(zswap_zpool_type); > - if (!has_zpool && strcmp(zswap_zpool_type, ZSWAP_ZPOOL_DEFAULT)) { > + if (!has_zpool && strcmp(zswap_zpool_type, > + CONFIG_ZSWAP_ZPOOL_DEFAULT)) { > pr_err("zpool %s not available, using default %s\n", > - zswap_zpool_type, ZSWAP_ZPOOL_DEFAULT); > + zswap_zpool_type, CONFIG_ZSWAP_ZPOOL_DEFAULT); > param_free_charp(&zswap_zpool_type); > - zswap_zpool_type = ZSWAP_ZPOOL_DEFAULT; > + zswap_zpool_type = CONFIG_ZSWAP_ZPOOL_DEFAULT; > has_zpool = zpool_has_pool(zswap_zpool_type); > } > if (!has_zpool) {