DEFINE_TRACE(block_split);
+/*
+ * Test patch to inline a certain number of bi_io_vec's inside the bio
+ * itself, to shrink a bio data allocation from two mempool calls to one
+ */
+#define BIO_INLINE_VECS 4
+
static mempool_t *bio_split_pool __read_mostly;
/*
* kzalloc() for the exact number of vecs right away.
*/
if (!bs)
- bvl = kzalloc(nr * sizeof(struct bio_vec), gfp_mask);
+ bvl = kmalloc(nr * sizeof(struct bio_vec), gfp_mask);
/*
* see comment near bvec_array define!
}
}
- if (bvl)
- memset(bvl, 0, bvec_nr_vecs(*idx) * sizeof(struct bio_vec));
-
return bvl;
}
{
void *p;
- if (bio->bi_io_vec)
+ if (bio_has_allocated_vec(bio))
bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio));
if (bio_integrity(bio))
static void bio_kmalloc_destructor(struct bio *bio)
{
- kfree(bio->bi_io_vec);
+ if (bio_has_allocated_vec(bio))
+ kfree(bio->bi_io_vec);
kfree(bio);
}
if (likely(nr_iovecs)) {
unsigned long uninitialized_var(idx);
- bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
+ if (nr_iovecs <= BIO_INLINE_VECS) {
+ idx = 0;
+ bvl = bio->bi_inline_vecs;
+ nr_iovecs = BIO_INLINE_VECS;
+ } else {
+ bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx,
+ bs);
+ nr_iovecs = bvec_nr_vecs(idx);
+ }
if (unlikely(!bvl)) {
if (bs)
mempool_free(bio, bs->bio_pool);
goto out;
}
bio->bi_flags |= idx << BIO_POOL_OFFSET;
- bio->bi_max_vecs = bvec_nr_vecs(idx);
+ bio->bi_max_vecs = nr_iovecs;
}
bio->bi_io_vec = bvl;
}
int i, ret;
int nr_pages = 0;
unsigned int len = 0;
+ unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0;
for (i = 0; i < iov_count; i++) {
unsigned long uaddr;
bio->bi_rw |= (!write_to_vm << BIO_RW);
ret = 0;
- i = 0;
+
+ if (map_data) {
+ nr_pages = 1 << map_data->page_order;
+ i = map_data->offset / PAGE_SIZE;
+ }
while (len) {
- unsigned int bytes;
+ unsigned int bytes = PAGE_SIZE;
- if (map_data)
- bytes = 1U << (PAGE_SHIFT + map_data->page_order);
- else
- bytes = PAGE_SIZE;
+ bytes -= offset;
if (bytes > len)
bytes = len;
if (map_data) {
- if (i == map_data->nr_entries) {
+ if (i == map_data->nr_entries * nr_pages) {
ret = -ENOMEM;
break;
}
- page = map_data->pages[i++];
- } else
+
+ page = map_data->pages[i / nr_pages];
+ page += (i % nr_pages);
+
+ i++;
+ } else {
page = alloc_page(q->bounce_gfp | gfp_mask);
- if (!page) {
- ret = -ENOMEM;
- break;
+ if (!page) {
+ ret = -ENOMEM;
+ break;
+ }
}
- if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
+ if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes)
break;
len -= bytes;
+ offset = 0;
}
if (ret)
/*
* success
*/
- if (!write_to_vm) {
+ if (!write_to_vm && (!map_data || !map_data->null_mapped)) {
ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 0);
if (ret)
goto cleanup;
*/
struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad)
{
+ unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec);
struct bio_set *bs;
bs = kzalloc(sizeof(*bs), GFP_KERNEL);
bs->front_pad = front_pad;
- bs->bio_slab = bio_find_or_create_slab(front_pad);
+ bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad);
if (!bs->bio_slab) {
kfree(bs);
return NULL;