diff options
Diffstat (limited to 'fs/ext4/ext4.h')
| -rw-r--r-- | fs/ext4/ext4.h | 55 |
1 files changed, 42 insertions, 13 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index fb9d2e2a9e42..6a1f013d23f7 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -135,16 +135,45 @@ enum SHIFT_DIRECTION { */ #define EXT4_MB_NUM_CRS 5 /* - * All possible allocation criterias for mballoc + * All possible allocation criterias for mballoc. Lower are faster. */ enum criteria { - CR0, - CR1, - CR1_5, - CR2, - CR3, + /* + * Used when number of blocks needed is a power of 2. This doesn't + * trigger any disk IO except prefetch and is the fastest criteria. + */ + CR_POWER2_ALIGNED, + + /* + * Tries to lookup in-memory data structures to find the most suitable + * group that satisfies goal request. No disk IO except block prefetch. + */ + CR_GOAL_LEN_FAST, + + /* + * Same as CR_GOAL_LEN_FAST but is allowed to reduce the goal length to + * the best available length for faster allocation. + */ + CR_BEST_AVAIL_LEN, + + /* + * Reads each block group sequentially, performing disk IO if necessary, to + * find find_suitable block group. Tries to allocate goal length but might trim + * the request if nothing is found after enough tries. + */ + CR_GOAL_LEN_SLOW, + + /* + * Finds the first free set of blocks and allocates those. This is only + * used in rare cases when CR_GOAL_LEN_SLOW also fails to allocate + * anything. + */ + CR_ANY_FREE, }; +/* criteria below which we use fast block scanning and avoid unnecessary IO */ +#define CR_FAST CR_GOAL_LEN_SLOW + /* * Flags used in mballoc's allocation_context flags field. * @@ -183,11 +212,11 @@ enum criteria { /* Do strict check for free blocks while retrying block allocation */ #define EXT4_MB_STRICT_CHECK 0x4000 /* Large fragment size list lookup succeeded at least once for cr = 0 */ -#define EXT4_MB_CR0_OPTIMIZED 0x8000 +#define EXT4_MB_CR_POWER2_ALIGNED_OPTIMIZED 0x8000 /* Avg fragment size rb tree lookup succeeded at least once for cr = 1 */ -#define EXT4_MB_CR1_OPTIMIZED 0x00010000 +#define EXT4_MB_CR_GOAL_LEN_FAST_OPTIMIZED 0x00010000 /* Avg fragment size rb tree lookup succeeded at least once for cr = 1.5 */ -#define EXT4_MB_CR1_5_OPTIMIZED 0x00020000 +#define EXT4_MB_CR_BEST_AVAIL_LEN_OPTIMIZED 0x00020000 struct ext4_allocation_request { /* target inode for block we're allocating */ @@ -1553,7 +1582,7 @@ struct ext4_sb_info { unsigned long s_mb_last_start; unsigned int s_mb_prefetch; unsigned int s_mb_prefetch_limit; - unsigned int s_mb_cr1_5_max_trim_order; + unsigned int s_mb_best_avail_max_trim_order; /* stats for buddy allocator */ atomic_t s_bal_reqs; /* number of reqs with len > 1 */ @@ -1566,9 +1595,9 @@ struct ext4_sb_info { atomic_t s_bal_len_goals; /* len goal hits */ atomic_t s_bal_breaks; /* too long searches */ atomic_t s_bal_2orders; /* 2^order hits */ - atomic_t s_bal_cr0_bad_suggestions; - atomic_t s_bal_cr1_bad_suggestions; - atomic_t s_bal_cr1_5_bad_suggestions; + atomic_t s_bal_p2_aligned_bad_suggestions; + atomic_t s_bal_goal_fast_bad_suggestions; + atomic_t s_bal_best_avail_bad_suggestions; atomic64_t s_bal_cX_groups_considered[EXT4_MB_NUM_CRS]; atomic64_t s_bal_cX_hits[EXT4_MB_NUM_CRS]; atomic64_t s_bal_cX_failed[EXT4_MB_NUM_CRS]; /* cX loop didn't find blocks */ |