Commit 604ea906 authored by Mike Snitzer's avatar Mike Snitzer
Browse files

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: default avatarMike Snitzer <snitzer@redhat.com>
parent 7d327fe0
......@@ -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);
}
......
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