From 604ea90641b45f41f8dee34ce45694f1e0c53a5a Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Thu, 9 Oct 2014 18:43:25 -0400 Subject: [PATCH] dm thin: adjust max_sectors_kb based on thinp blocksize Allows for filesystems to submit bios that are a factor of the thinp blocksize, improving dm-thinp efficiency (particularly when the data volume is RAID). Also set io_min to max_sectors_kb if it is a factor of the thinp blocksize. Signed-off-by: Mike Snitzer --- drivers/md/dm-thin.c | 34 +++++++++++++++++++++++++++++++--- 1 file changed, 31 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 91b430b883fd..de55ae9d4926 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -3242,15 +3243,42 @@ static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits) { struct pool_c *pt = ti->private; struct pool *pool = pt->pool; - uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; + sector_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; + + /* + * Adjust max_sectors_kb to highest possible power-of-2 + * factor of pool->sectors_per_block. + */ + if (limits->max_hw_sectors & (limits->max_hw_sectors - 1)) + limits->max_sectors = rounddown_pow_of_two(limits->max_hw_sectors); + else + limits->max_sectors = limits->max_hw_sectors; + + if (limits->max_sectors < pool->sectors_per_block) { + while (!is_factor(pool->sectors_per_block, limits->max_sectors)) { + if ((limits->max_sectors & (limits->max_sectors - 1)) == 0) + limits->max_sectors--; + limits->max_sectors = rounddown_pow_of_two(limits->max_sectors); + } + } else if (block_size_is_power_of_two(pool)) { + /* max_sectors_kb is >= power-of-2 thinp blocksize */ + while (!is_factor(limits->max_sectors, pool->sectors_per_block)) { + if ((limits->max_sectors & (limits->max_sectors - 1)) == 0) + limits->max_sectors--; + limits->max_sectors = rounddown_pow_of_two(limits->max_sectors); + } + } /* * If the system-determined stacked limits are compatible with the * pool's blocksize (io_opt is a factor) do not override them. */ if (io_opt_sectors < pool->sectors_per_block || - do_div(io_opt_sectors, pool->sectors_per_block)) { - blk_limits_io_min(limits, pool->sectors_per_block << SECTOR_SHIFT); + !is_factor(io_opt_sectors, pool->sectors_per_block)) { + if (is_factor(pool->sectors_per_block, limits->max_sectors)) + blk_limits_io_min(limits, limits->max_sectors << SECTOR_SHIFT); + else + blk_limits_io_min(limits, pool->sectors_per_block << SECTOR_SHIFT); blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT); } -- 2.20.1