dm bufio: relax alignment constraint on slab cache

The I/O buffer doesn't have to be aligned on block size granularity,
relax alignment to ARCH_KMALLOC_MINALIGN (required to allow DMA from
slab cache memory on some architectures).

Also, set SLAB_RECLAIM_ACCOUNT so that the memory allocated from the
cache is accounted as reclaimable and doesn't inflate the 'used' entry
in the free command.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index ef6365e..c57aefb 100644 (file)
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -618,7 +618,6 @@ static void use_inline_bio(struct dm_buffer *b, int rw, sector_t sector,
                unsigned this_step = min((unsigned)(PAGE_SIZE - offset_in_page(ptr)), len);
                if (!bio_add_page(&b->bio, virt_to_page(ptr), this_step,
                                  offset_in_page(ptr))) {
-                       BUG_ON(b->c->block_size <= PAGE_SIZE);
                        use_dmio(b, rw, sector, n_sectors, offset, end_io);
                        return;
                }
@@ -1686,7 +1685,8 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign
        if (block_size < PAGE_SIZE) {
                char name[26];
                snprintf(name, sizeof name, "dm_bufio_cache-%u", c->block_size);
-               c->slab_cache = kmem_cache_create(name, c->block_size, c->block_size, 0, NULL);
+               c->slab_cache = kmem_cache_create(name, c->block_size, ARCH_KMALLOC_MINALIGN,
+                                                 SLAB_RECLAIM_ACCOUNT, NULL);
                if (!c->slab_cache) {
                        r = -ENOMEM;
                        goto bad;