commit 762380ad9322951cea4ce9d24864265f9c66a916
author Jens Axboe <axboe@fb.com> Thu Jun 05 13:38:39 2014 -0600
committer Jens Axboe <axboe@fb.com> Thu Jun 05 13:38:39 2014 -0600
tree 9ec3fe551583dcb9243d02a9728511e99216dcdc
parent 046f153343e33dcad1be7f6249ea6ff1c6fd9b58

block: add notion of a chunk size for request merging

Some drivers have different limits on what size a request should
optimally be, depending on the offset of the request. Similar to
dividing a device into chunks. Add a setting that allows the driver
to inform the block layer of such a chunk size. The block layer will
then prevent merging across the chunks.

This is needed to optimally support NVMe with a non-zero stripe size.

Signed-off-by: Jens Axboe <axboe@fb.com>