From be04c14a1bd262a49e5764e5cf864259b7e740fd Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Wed, 14 Jun 2023 21:47:46 -0400 Subject: [PATCH] dm: use op specific max_sectors when splitting abnormal io Split abnormal IO in terms of the corresponding operation specific max_sectors (max_discard_sectors, max_secure_erase_sectors or max_write_zeroes_sectors). This fixes a significant dm-thinp discard performance regression that was introduced with commit e2dd8aca2d76 ("dm bio prison v1: improve concurrent IO performance"). Relative to discard: max_discard_sectors is used instead of max_sectors; which fixes excessive discard splitting (e.g. max_sectors=128K vs max_discard_sectors=64M). Tested by discarding an 1 Petabyte dm-thin device: lvcreate -V 1125899906842624B -T test/pool -n thin time blkdiscard /dev/test/thin Before this fix (splitting discards every 128K): ~116m After this fix (splitting discards every 64M) : 0m33.460s Reported-by: Zorro Lang Fixes: 06961c487a33 ("dm: split discards further if target sets max_discard_granularity") Requires: 13f6facf3fae ("dm: allow targets to require splitting WRITE_ZEROES and SECURE_ERASE") Fixes: e2dd8aca2d76 ("dm bio prison v1: improve concurrent IO performance") Signed-off-by: Mike Snitzer --- drivers/md/dm.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 8488547fc00d..fffb0cbe2ac8 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1172,7 +1172,8 @@ static inline sector_t max_io_len_target_boundary(struct dm_target *ti, } static sector_t __max_io_len(struct dm_target *ti, sector_t sector, - unsigned int max_granularity) + unsigned int max_granularity, + unsigned int max_sectors) { sector_t target_offset = dm_target_offset(ti, sector); sector_t len = max_io_len_target_boundary(ti, target_offset); @@ -1186,13 +1187,13 @@ static sector_t __max_io_len(struct dm_target *ti, sector_t sector, if (!max_granularity) return len; return min_t(sector_t, len, - min(queue_max_sectors(ti->table->md->queue), + min(max_sectors ? : queue_max_sectors(ti->table->md->queue), blk_chunk_sectors_left(target_offset, max_granularity))); } static inline sector_t max_io_len(struct dm_target *ti, sector_t sector) { - return __max_io_len(ti, sector, ti->max_io_len); + return __max_io_len(ti, sector, ti->max_io_len, 0); } int dm_set_target_max_io_len(struct dm_target *ti, sector_t len) @@ -1581,12 +1582,13 @@ static void __send_empty_flush(struct clone_info *ci) static void __send_changing_extent_only(struct clone_info *ci, struct dm_target *ti, unsigned int num_bios, - unsigned int max_granularity) + unsigned int max_granularity, + unsigned int max_sectors) { unsigned int len, bios; len = min_t(sector_t, ci->sector_count, - __max_io_len(ti, ci->sector, max_granularity)); + __max_io_len(ti, ci->sector, max_granularity, max_sectors)); atomic_add(num_bios, &ci->io->io_count); bios = __send_duplicate_bios(ci, ti, num_bios, &len); @@ -1623,23 +1625,27 @@ static blk_status_t __process_abnormal_io(struct clone_info *ci, { unsigned int num_bios = 0; unsigned int max_granularity = 0; + unsigned int max_sectors = 0; struct queue_limits *limits = dm_get_queue_limits(ti->table->md); switch (bio_op(ci->bio)) { case REQ_OP_DISCARD: num_bios = ti->num_discard_bios; + max_sectors = limits->max_discard_sectors; if (ti->max_discard_granularity) - max_granularity = limits->max_discard_sectors; + max_granularity = max_sectors; break; case REQ_OP_SECURE_ERASE: num_bios = ti->num_secure_erase_bios; + max_sectors = limits->max_secure_erase_sectors; if (ti->max_secure_erase_granularity) - max_granularity = limits->max_secure_erase_sectors; + max_granularity = max_sectors; break; case REQ_OP_WRITE_ZEROES: num_bios = ti->num_write_zeroes_bios; + max_sectors = limits->max_write_zeroes_sectors; if (ti->max_write_zeroes_granularity) - max_granularity = limits->max_write_zeroes_sectors; + max_granularity = max_sectors; break; default: break; @@ -1654,7 +1660,8 @@ static blk_status_t __process_abnormal_io(struct clone_info *ci, if (unlikely(!num_bios)) return BLK_STS_NOTSUPP; - __send_changing_extent_only(ci, ti, num_bios, max_granularity); + __send_changing_extent_only(ci, ti, num_bios, + max_granularity, max_sectors); return BLK_STS_OK; } -- 2.41.0