From be500ed721a6ec8d49bf0814c277ce7162acee0e Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Tue, 13 Apr 2021 11:03:45 +0100 Subject: dm space maps: improve performance with inc/dec on ranges of blocks When we break sharing on btree nodes we typically need to increment the reference counts to every value held in the node. This can cause a lot of repeated calls to the space maps. Fix this by changing the interface to the space map inc/dec methods to take ranges of adjacent blocks to be operated on. For installations that are using a lot of snapshots this will reduce cpu overhead of fundamental operations such as provisioning a new block, or deleting a snapshot, by as much as 10 times. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer --- drivers/md/persistent-data/dm-array.c | 52 +++++++++++++++++++---------------- 1 file changed, 28 insertions(+), 24 deletions(-) (limited to 'drivers/md/persistent-data/dm-array.c') diff --git a/drivers/md/persistent-data/dm-array.c b/drivers/md/persistent-data/dm-array.c index 185dc60360b5..3a963d783a86 100644 --- a/drivers/md/persistent-data/dm-array.c +++ b/drivers/md/persistent-data/dm-array.c @@ -108,12 +108,10 @@ static void *element_at(struct dm_array_info *info, struct array_block *ab, * in an array block. */ static void on_entries(struct dm_array_info *info, struct array_block *ab, - void (*fn)(void *, const void *)) + void (*fn)(void *, const void *, unsigned)) { - unsigned i, nr_entries = le32_to_cpu(ab->nr_entries); - - for (i = 0; i < nr_entries; i++) - fn(info->value_type.context, element_at(info, ab, i)); + unsigned nr_entries = le32_to_cpu(ab->nr_entries); + fn(info->value_type.context, element_at(info, ab, 0), nr_entries); } /* @@ -175,19 +173,18 @@ static int alloc_ablock(struct dm_array_info *info, size_t size_of_block, static void fill_ablock(struct dm_array_info *info, struct array_block *ab, const void *value, unsigned new_nr) { - unsigned i; - uint32_t nr_entries; + uint32_t nr_entries, delta, i; struct dm_btree_value_type *vt = &info->value_type; BUG_ON(new_nr > le32_to_cpu(ab->max_entries)); BUG_ON(new_nr < le32_to_cpu(ab->nr_entries)); nr_entries = le32_to_cpu(ab->nr_entries); - for (i = nr_entries; i < new_nr; i++) { - if (vt->inc) - vt->inc(vt->context, value); + delta = new_nr - nr_entries; + if (vt->inc) + vt->inc(vt->context, value, delta); + for (i = nr_entries; i < new_nr; i++) memcpy(element_at(info, ab, i), value, vt->size); - } ab->nr_entries = cpu_to_le32(new_nr); } @@ -199,17 +196,16 @@ static void fill_ablock(struct dm_array_info *info, struct array_block *ab, static void trim_ablock(struct dm_array_info *info, struct array_block *ab, unsigned new_nr) { - unsigned i; - uint32_t nr_entries; + uint32_t nr_entries, delta; struct dm_btree_value_type *vt = &info->value_type; BUG_ON(new_nr > le32_to_cpu(ab->max_entries)); BUG_ON(new_nr > le32_to_cpu(ab->nr_entries)); nr_entries = le32_to_cpu(ab->nr_entries); - for (i = nr_entries; i > new_nr; i--) - if (vt->dec) - vt->dec(vt->context, element_at(info, ab, i - 1)); + delta = nr_entries - new_nr; + if (vt->dec) + vt->dec(vt->context, element_at(info, ab, new_nr - 1), delta); ab->nr_entries = cpu_to_le32(new_nr); } @@ -573,16 +569,17 @@ static int grow(struct resize *resize) * These are the value_type functions for the btree elements, which point * to array blocks. */ -static void block_inc(void *context, const void *value) +static void block_inc(void *context, const void *value, unsigned count) { - __le64 block_le; + const __le64 *block_le = value; struct dm_array_info *info = context; + unsigned i; - memcpy(&block_le, value, sizeof(block_le)); - dm_tm_inc(info->btree_info.tm, le64_to_cpu(block_le)); + for (i = 0; i < count; i++, block_le++) + dm_tm_inc(info->btree_info.tm, le64_to_cpu(*block_le)); } -static void block_dec(void *context, const void *value) +static void __block_dec(void *context, const void *value) { int r; uint64_t b; @@ -621,6 +618,13 @@ static void block_dec(void *context, const void *value) dm_tm_dec(info->btree_info.tm, b); } +static void block_dec(void *context, const void *value, unsigned count) +{ + unsigned i; + for (i = 0; i < count; i++, value += sizeof(__le64)) + __block_dec(context, value); +} + static int block_equal(void *context, const void *value1, const void *value2) { return !memcmp(value1, value2, sizeof(__le64)); @@ -711,7 +715,7 @@ static int populate_ablock_with_values(struct dm_array_info *info, struct array_ return r; if (vt->inc) - vt->inc(vt->context, element_at(info, ab, i)); + vt->inc(vt->context, element_at(info, ab, i), 1); } ab->nr_entries = cpu_to_le32(new_nr); @@ -822,9 +826,9 @@ static int array_set_value(struct dm_array_info *info, dm_block_t root, old_value = element_at(info, ab, entry); if (vt->dec && (!vt->equal || !vt->equal(vt->context, old_value, value))) { - vt->dec(vt->context, old_value); + vt->dec(vt->context, old_value, 1); if (vt->inc) - vt->inc(vt->context, value); + vt->inc(vt->context, value, 1); } memcpy(old_value, value, info->value_type.size); -- cgit v1.2.3-59-g8ed1b