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/dm-thin-metadata.c | 91 +++++++++++++++++++++++++------------------ 1 file changed, 53 insertions(+), 38 deletions(-) (limited to 'drivers/md/dm-thin-metadata.c') diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index e75b20480e46..c88ed14d49e6 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -311,28 +311,53 @@ static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t) *t = v & ((1 << 24) - 1); } -static void data_block_inc(void *context, const void *value_le) +/* + * It's more efficient to call dm_sm_{inc,dec}_blocks as few times as + * possible. 'with_runs' reads contiguous runs of blocks, and calls the + * given sm function. + */ +typedef int (*run_fn)(struct dm_space_map *, dm_block_t, dm_block_t); + +static void with_runs(struct dm_space_map *sm, const __le64 *value_le, unsigned count, run_fn fn) { - struct dm_space_map *sm = context; - __le64 v_le; - uint64_t b; + uint64_t b, begin, end; uint32_t t; + bool in_run = false; + unsigned i; - memcpy(&v_le, value_le, sizeof(v_le)); - unpack_block_time(le64_to_cpu(v_le), &b, &t); - dm_sm_inc_block(sm, b); + for (i = 0; i < count; i++, value_le++) { + /* We know value_le is 8 byte aligned */ + unpack_block_time(le64_to_cpu(*value_le), &b, &t); + + if (in_run) { + if (b == end) { + end++; + } else { + fn(sm, begin, end); + begin = b; + end = b + 1; + } + } else { + in_run = true; + begin = b; + end = b + 1; + } + } + + if (in_run) + fn(sm, begin, end); } -static void data_block_dec(void *context, const void *value_le) +static void data_block_inc(void *context, const void *value_le, unsigned count) { - struct dm_space_map *sm = context; - __le64 v_le; - uint64_t b; - uint32_t t; + with_runs((struct dm_space_map *) context, + (const __le64 *) value_le, count, dm_sm_inc_blocks); +} - memcpy(&v_le, value_le, sizeof(v_le)); - unpack_block_time(le64_to_cpu(v_le), &b, &t); - dm_sm_dec_block(sm, b); +static void data_block_dec(void *context, const void *value_le, unsigned count) +{ + with_runs((struct dm_space_map *) context, + (const __le64 *) value_le, count, dm_sm_dec_blocks); } static int data_block_equal(void *context, const void *value1_le, const void *value2_le) @@ -349,27 +374,25 @@ static int data_block_equal(void *context, const void *value1_le, const void *va return b1 == b2; } -static void subtree_inc(void *context, const void *value) +static void subtree_inc(void *context, const void *value, unsigned count) { struct dm_btree_info *info = context; - __le64 root_le; - uint64_t root; + const __le64 *root_le = value; + unsigned i; - memcpy(&root_le, value, sizeof(root_le)); - root = le64_to_cpu(root_le); - dm_tm_inc(info->tm, root); + for (i = 0; i < count; i++, root_le++) + dm_tm_inc(info->tm, le64_to_cpu(*root_le)); } -static void subtree_dec(void *context, const void *value) +static void subtree_dec(void *context, const void *value, unsigned count) { struct dm_btree_info *info = context; - __le64 root_le; - uint64_t root; + const __le64 *root_le = value; + unsigned i; - memcpy(&root_le, value, sizeof(root_le)); - root = le64_to_cpu(root_le); - if (dm_btree_del(info, root)) - DMERR("btree delete failed"); + for (i = 0; i < count; i++, root_le++) + if (dm_btree_del(info, le64_to_cpu(*root_le))) + DMERR("btree delete failed"); } static int subtree_equal(void *context, const void *value1_le, const void *value2_le) @@ -1761,11 +1784,7 @@ int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_ int r = 0; pmd_write_lock(pmd); - for (; b != e; b++) { - r = dm_sm_inc_block(pmd->data_sm, b); - if (r) - break; - } + r = dm_sm_inc_blocks(pmd->data_sm, b, e); pmd_write_unlock(pmd); return r; @@ -1776,11 +1795,7 @@ int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_ int r = 0; pmd_write_lock(pmd); - for (; b != e; b++) { - r = dm_sm_dec_block(pmd->data_sm, b); - if (r) - break; - } + r = dm_sm_dec_blocks(pmd->data_sm, b, e); pmd_write_unlock(pmd); return r; -- cgit v1.2.3-59-g8ed1b