The 10/13/2016 14:09, Jens Axboe wrote: > On 10/13/2016 02:06 PM, Dan Williams wrote: > >On Thu, Oct 13, 2016 at 12:53 PM, Adam Manzanares > ><adam.manzanares@xxxxxxxx> wrote: > >>Patch adds an association between iocontext ioprio and the ioprio of a > >>request. This value is set in blk_rq_set_prio which takes the request and > >>the ioc as arguments. If the ioc is valid in blk_rq_set_prio then the > >>iopriority of the request is set as the iopriority of the ioc. In > >>init_request_from_bio a check is made to see if the ioprio of the bio is > >>valid and if so then the request prio comes from the bio. > >> > >>Signed-off-by: Adam Manzananares <adam.manzanares@xxxxxxx> > >>--- > >> block/blk-core.c | 4 +++- > >> include/linux/blkdev.h | 14 ++++++++++++++ > >> 2 files changed, 17 insertions(+), 1 deletion(-) > >> > >>diff --git a/block/blk-core.c b/block/blk-core.c > >>index 14d7c07..361b1b9 100644 > >>--- a/block/blk-core.c > >>+++ b/block/blk-core.c > >>@@ -1153,6 +1153,7 @@ static struct request *__get_request(struct request_list *rl, int op, > >> > >> blk_rq_init(q, rq); > >> blk_rq_set_rl(rq, rl); > >>+ blk_rq_set_prio(rq, ioc); > >> req_set_op_attrs(rq, op, op_flags | REQ_ALLOCED); > >> > >> /* init elvpriv */ > >>@@ -1656,7 +1657,8 @@ void init_request_from_bio(struct request *req, struct bio *bio) > >> > >> req->errors = 0; > >> req->__sector = bio->bi_iter.bi_sector; > >>- req->ioprio = bio_prio(bio); > >>+ if (ioprio_valid(bio_prio(bio))) > >>+ req->ioprio = bio_prio(bio); > > > >Should we use ioprio_best() here? If req->ioprio and bio_prio() > >disagree one side has explicitly asked for a higher priority. > > It's a good question - but if priority has been set in the bio, it makes > sense that that would take priority over the general setting for the > task/io context. So I think the patch is correct as-is. > > Adam, you'll want to rewrite the commit message though. A good commit > message should explain WHY the change is made, not detail the code > implementation of it. Got it I'll send something out soon. > > -- > Jens Axboe > Take care, Adam -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
