block: support different tag allocation policy

The libata tag allocation is using a round-robin policy. Next patch will
make libata use block generic tag allocation, so let's add a policy to
tag allocation.

Currently two policies: FIFO (default) and round-robin.

Cc: Jens Axboe <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Shaohua Li <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This commit is contained in:
Shaohua Li 2015-01-15 17:32:25 -08:00 • committed by Jens Axboe
commit ee1b6f7aff
6 changed files with 39 additions and 13 deletions

View file

@ -423,7 +423,7 @@ static int osdblk_init_disk(struct osdblk_device *osdev)
}
/* switch queue to TCQ mode; allocate tag map */
rc = blk_queue_init_tags(q, OSDBLK_MAX_REQ, NULL);
rc = blk_queue_init_tags(q, OSDBLK_MAX_REQ, NULL, BLK_TAG_ALLOC_FIFO);
if (rc) {
blk_cleanup_queue(q);
put_disk(disk);