diff options
Diffstat (limited to 'drivers/block/zram/zram_drv.h')
| -rw-r--r-- | drivers/block/zram/zram_drv.h | 71 |
1 files changed, 42 insertions, 29 deletions
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 80c3b43b4828..c6d94501376c 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -17,7 +17,6 @@ #include <linux/rwsem.h> #include <linux/zsmalloc.h> -#include <linux/crypto.h> #include "zcomp.h" @@ -28,60 +27,61 @@ #define ZRAM_SECTOR_PER_LOGICAL_BLOCK \ (1 << (ZRAM_LOGICAL_BLOCK_SHIFT - SECTOR_SHIFT)) - /* - * The lower ZRAM_FLAG_SHIFT bits of table.flags is for - * object size (excluding header), the higher bits is for - * zram_pageflags. + * ZRAM is mainly used for memory efficiency so we want to keep memory + * footprint small and thus squeeze size and zram pageflags into a flags + * member. The lower ZRAM_FLAG_SHIFT bits is for object size (excluding + * header), which cannot be larger than PAGE_SIZE (requiring PAGE_SHIFT + * bits), the higher bits are for zram_pageflags. * - * zram is mainly used for memory efficiency so we want to keep memory - * footprint small so we can squeeze size and flags into a field. - * The lower ZRAM_FLAG_SHIFT bits is for object size (excluding header), - * the higher bits is for zram_pageflags. + * We use BUILD_BUG_ON() to make sure that zram pageflags don't overflow. */ -#define ZRAM_FLAG_SHIFT 24 +#define ZRAM_FLAG_SHIFT (PAGE_SHIFT + 1) + +/* Only 2 bits are allowed for comp priority index */ +#define ZRAM_COMP_PRIORITY_MASK 0x3 /* Flags for zram pages (table[page_no].flags) */ enum zram_pageflags { - /* zram slot is locked */ - ZRAM_LOCK = ZRAM_FLAG_SHIFT, - ZRAM_SAME, /* Page consists the same element */ + ZRAM_SAME = ZRAM_FLAG_SHIFT, /* Page consists the same element */ + ZRAM_ENTRY_LOCK, /* entry access lock bit */ ZRAM_WB, /* page is stored on backing_device */ - ZRAM_UNDER_WB, /* page is under writeback */ + ZRAM_PP_SLOT, /* Selected for post-processing */ ZRAM_HUGE, /* Incompressible page */ ZRAM_IDLE, /* not accessed page since last idle marking */ + ZRAM_INCOMPRESSIBLE, /* none of the algorithms could compress it */ + + ZRAM_COMP_PRIORITY_BIT1, /* First bit of comp priority index */ + ZRAM_COMP_PRIORITY_BIT2, /* Second bit of comp priority index */ __NR_ZRAM_PAGEFLAGS, }; -/*-- Data structures */ - -/* Allocated for each disk page */ +/* + * Allocated for each disk page. We use bit-lock (ZRAM_ENTRY_LOCK bit + * of flags) to save memory. There can be plenty of entries and standard + * locking primitives (e.g. mutex) will significantly increase sizeof() + * of each entry and hence of the meta table. + */ struct zram_table_entry { - union { - unsigned long handle; - unsigned long element; - }; + unsigned long handle; unsigned long flags; -#ifdef CONFIG_ZRAM_MEMORY_TRACKING +#ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME ktime_t ac_time; #endif + struct lockdep_map dep_map; }; struct zram_stats { atomic64_t compr_data_size; /* compressed size of pages stored */ - atomic64_t num_reads; /* failed + successful */ - atomic64_t num_writes; /* --do-- */ atomic64_t failed_reads; /* can happen when memory is too low */ atomic64_t failed_writes; /* can happen when memory is too low */ - atomic64_t invalid_io; /* non-page-aligned I/O requests */ atomic64_t notify_free; /* no. of swap slot free notifications */ atomic64_t same_pages; /* no. of same element filled pages */ atomic64_t huge_pages; /* no. of huge pages */ atomic64_t huge_pages_since; /* no. of huge pages since zram set up */ atomic64_t pages_stored; /* no. of pages currently stored */ atomic_long_t max_used_pages; /* no. of maximum pages stored */ - atomic64_t writestall; /* no. of write slow paths */ atomic64_t miss_free; /* no. of missed free */ #ifdef CONFIG_ZRAM_WRITEBACK atomic64_t bd_count; /* no. of pages in backing device */ @@ -90,10 +90,21 @@ struct zram_stats { #endif }; +#ifdef CONFIG_ZRAM_MULTI_COMP +#define ZRAM_PRIMARY_COMP 0U +#define ZRAM_SECONDARY_COMP 1U +#define ZRAM_MAX_COMPS 4U +#else +#define ZRAM_PRIMARY_COMP 0U +#define ZRAM_SECONDARY_COMP 0U +#define ZRAM_MAX_COMPS 1U +#endif + struct zram { struct zram_table_entry *table; struct zs_pool *mem_pool; - struct zcomp *comp; + struct zcomp *comps[ZRAM_MAX_COMPS]; + struct zcomp_params params[ZRAM_MAX_COMPS]; struct gendisk *disk; /* Prevent concurrent execution of device init */ struct rw_semaphore init_lock; @@ -108,15 +119,16 @@ struct zram { * we can store in a disk. */ u64 disksize; /* bytes */ - char compressor[CRYPTO_MAX_ALG_NAME]; + const char *comp_algs[ZRAM_MAX_COMPS]; + s8 num_active_comps; /* * zram is claimed so open request will be failed */ bool claim; /* Protected by disk->open_mutex */ #ifdef CONFIG_ZRAM_WRITEBACK struct file *backing_dev; - spinlock_t wb_limit_lock; bool wb_limit_enable; + u32 wb_batch_size; u64 bd_wb_limit; struct block_device *bdev; unsigned long *bitmap; @@ -125,5 +137,6 @@ struct zram { #ifdef CONFIG_ZRAM_MEMORY_TRACKING struct dentry *debugfs_dir; #endif + atomic_t pp_in_progress; }; #endif |