diff options
| author | Keun-young Park <keunyoung@google.com> | 2016-11-14 18:25:15 -0800 |
|---|---|---|
| committer | Keun-young Park <keunyoung@google.com> | 2016-12-07 14:22:22 -0800 |
| commit | ace74ccf82cfb2b73ce1df2e698d20c2fbc559dd (patch) | |
| tree | 527207a0dac7ac72f19182686922eec81a865699 /drivers | |
| parent | 25dcb75878cd3b685a70c688758a4d3726e92703 (diff) | |
ANDROID: dm verity: add minimum prefetch size
- For device like eMMC, it gives better performance to read more hash
blocks at a time.
- For android, set it to default 128.
For other devices, set it to 1 which is the same as now.
- saved boot-up time by 300ms in tested device
bug: 32246564
Cc: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Keun-young Park <keunyoung@google.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/md/Kconfig | 16 | ||||
| -rw-r--r-- | drivers/md/dm-verity-target.c | 9 |
2 files changed, 24 insertions, 1 deletions
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 6035794bc1f2..3d237a03dab3 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -458,6 +458,21 @@ config DM_VERITY If unsure, say N. +config DM_VERITY_HASH_PREFETCH_MIN_SIZE_128 + bool "Prefetch size 128" + +config DM_VERITY_HASH_PREFETCH_MIN_SIZE + int "Verity hash prefetch minimum size" + depends on DM_VERITY + range 1 4096 + default 128 if DM_VERITY_HASH_PREFETCH_MIN_SIZE_128 + default 1 + ---help--- + This sets minimum number of hash blocks to prefetch for dm-verity. + For devices like eMMC, having larger prefetch size like 128 can improve + performance with increased memory consumption for keeping more hashes + in RAM. + config DM_VERITY_FEC bool "Verity forward error correction support" depends on DM_VERITY @@ -510,6 +525,7 @@ config DM_ANDROID_VERITY depends on ASYMMETRIC_KEY_TYPE depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE depends on MD_LINEAR + select DM_VERITY_HASH_PREFETCH_MIN_SIZE_128 ---help--- This device-mapper target is virtually a VERITY target. This target is setup by reading the metadata contents piggybacked diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index 9d3d4b297201..c7e97cf6e7fb 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -501,6 +501,7 @@ static void verity_prefetch_io(struct work_struct *work) container_of(work, struct dm_verity_prefetch_work, work); struct dm_verity *v = pw->v; int i; + sector_t prefetch_size; for (i = v->levels - 2; i >= 0; i--) { sector_t hash_block_start; @@ -523,8 +524,14 @@ static void verity_prefetch_io(struct work_struct *work) hash_block_end = v->hash_blocks - 1; } no_prefetch_cluster: + // for emmc, it is more efficient to send bigger read + prefetch_size = max((sector_t)CONFIG_DM_VERITY_HASH_PREFETCH_MIN_SIZE, + hash_block_end - hash_block_start + 1); + if ((hash_block_start + prefetch_size) >= (v->hash_start + v->hash_blocks)) { + prefetch_size = hash_block_end - hash_block_start + 1; + } dm_bufio_prefetch(v->bufio, hash_block_start, - hash_block_end - hash_block_start + 1); + prefetch_size); } kfree(pw); |