From 428e4698642794444cdb26c148a827f22c28d546 Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Mon, 3 Mar 2014 10:37:24 -0500 Subject: [PATCH] dm bitset: only flush the current word if it has been dirtied This change offers a big performance boost for dm-era. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer --- drivers/md/persistent-data/dm-bitset.c | 10 +++++++++- drivers/md/persistent-data/dm-bitset.h | 1 + 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/md/persistent-data/dm-bitset.c b/drivers/md/persistent-data/dm-bitset.c index cd9a86d4cdf0..36f7cc2c7109 100644 --- a/drivers/md/persistent-data/dm-bitset.c +++ b/drivers/md/persistent-data/dm-bitset.c @@ -65,7 +65,7 @@ int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root, int r; __le64 value; - if (!info->current_index_set) + if (!info->current_index_set || !info->dirty) return 0; value = cpu_to_le64(info->current_bits); @@ -77,6 +77,8 @@ int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root, return r; info->current_index_set = false; + info->dirty = false; + return 0; } EXPORT_SYMBOL_GPL(dm_bitset_flush); @@ -94,6 +96,8 @@ static int read_bits(struct dm_disk_bitset *info, dm_block_t root, info->current_bits = le64_to_cpu(value); info->current_index_set = true; info->current_index = array_index; + info->dirty = false; + return 0; } @@ -126,6 +130,8 @@ int dm_bitset_set_bit(struct dm_disk_bitset *info, dm_block_t root, return r; set_bit(b, (unsigned long *) &info->current_bits); + info->dirty = true; + return 0; } EXPORT_SYMBOL_GPL(dm_bitset_set_bit); @@ -141,6 +147,8 @@ int dm_bitset_clear_bit(struct dm_disk_bitset *info, dm_block_t root, return r; clear_bit(b, (unsigned long *) &info->current_bits); + info->dirty = true; + return 0; } EXPORT_SYMBOL_GPL(dm_bitset_clear_bit); diff --git a/drivers/md/persistent-data/dm-bitset.h b/drivers/md/persistent-data/dm-bitset.h index e1b9bea14aa1..c2287d672ef5 100644 --- a/drivers/md/persistent-data/dm-bitset.h +++ b/drivers/md/persistent-data/dm-bitset.h @@ -71,6 +71,7 @@ struct dm_disk_bitset { uint64_t current_bits; bool current_index_set:1; + bool dirty:1; }; /* -- 2.20.1