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authorMike Snitzer <snitzer@redhat.com>2014-10-09 18:43:25 -0400
committerMike Snitzer <snitzer@redhat.com>2014-11-10 15:25:27 -0500
commit604ea90641b45f41f8dee34ce45694f1e0c53a5a (patch)
treea438aa17637a26cf32284b635c792f83e42ad6b2 /drivers/md/dm-thin.c
parent7d327fe051edcccf54da7b6733c58992473f228b (diff)
downloadlinux-604ea90641b45f41f8dee34ce45694f1e0c53a5a.tar.gz
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 <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-thin.c')
-rw-r--r--drivers/md/dm-thin.c34
1 files 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 <linux/device-mapper.h>
#include <linux/dm-io.h>
#include <linux/dm-kcopyd.h>
+#include <linux/log2.h>
#include <linux/list.h>
#include <linux/rculist.h>
#include <linux/init.h>
@@ -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);
}