On 7/30/25 10:22, Yu Kuai wrote:
From: Yu Kuai <yukuai3@xxxxxxxxxx> Currently, both mq-deadline and bfq have global spin lock that will be grabbed inside elevator methods like dispatch_request, insert_requests, and bio_merge. And the global lock is the main reason mq-deadline and bfq can't scale very well. While dispatching request, blk_mq_get_disatpch_budget() and blk_mq_get_driver_tag() must be called, and they are not ready to be called inside elevator methods, hence introduce a new method like dispatch_requests is not possible. Hence introduce a new high level elevator lock, currently it is protecting dispatch_request only. Following patches will convert mq-deadline and bfq to use this lock and finally support request batch dispatching by calling the method multiple time while holding the lock. Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> --- block/blk-mq-sched.c | 6 ++++++ block/elevator.c | 1 + block/elevator.h | 4 ++-- 3 files changed, 9 insertions(+), 2 deletions(-)
Reviewed-by: Hannes Reinecke <hare@xxxxxxx> Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@xxxxxxx +49 911 74053 688 SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich
