diff options
| author |   Junichi Nomura <j-nomura@ce.jp.nec.com> | 2014-10-03 11:55:26 +0000 |
|---|---|---|
| committer |   Mike Snitzer <snitzer@redhat.com> | 2014-10-05 20:03:34 -0400 |
| commit | 3d8aab2d2cca2dc878e396196d07889129440798 (patch) | |
| tree | 3b3e54566597979e4da22fadf80794dd72b8af51 /drivers/md | |
| parent | dm: remove nr_iovecs parameter from alloc_tio() (diff) | |
| download | linux-dev-3d8aab2d2cca2dc878e396196d07889129440798.tar.xz linux-dev-3d8aab2d2cca2dc878e396196d07889129440798.zip | |
dm: use bioset_create_nobvec()
Since DM core uses bio_clone_fast() for both bio-based and request-based
DM devices there is no need for DM's bioset to have a bvec mempool.
With this patch, on arch with 4KB page for example, memory usage will be
reduced by 64KB for each bio-based DM device and 1MB for each
request-based DM device.
For example, when you create 10,000 bio-based DM devices and 1,000
request-based DM devices, memory usage of biovec under no load is:
# grep biovec /proc/slabinfo
biovec-256 418068 418068 4096 ...
biovec-128 0 0 2048 ...
biovec-64 0 0 1024 ...
biovec-16 0 0 256 ...
With this patch series applied, the usage becomes:
# grep biovec /proc/slabinfo
biovec-256 116 116 4096 ...
biovec-128 0 0 2048 ...
biovec-64 0 0 1024 ...
biovec-16 0 0 256 ...
So 4096 * (418068 - 116) = 1.6GB of memory is saved in this example.
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 0b9de07d585b..56a2c74c9a3f 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2895,7 +2895,7 @@ struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, u if (!pools->io_pool) goto out; - pools->bs = bioset_create(pool_size, front_pad); + pools->bs = bioset_create_nobvec(pool_size, front_pad); if (!pools->bs) goto out; |