On 23/08/2019 02:15, Damien Le Moal wrote: > Introduce the elevator feature ELEVATOR_F_ZONED_BLOCK_DEV to indicate > that an elevator supports zoned block device write ordering control. > > Mark the mq-deadline as supporting this feature which is implemented > using zone write locking. SCSI zoned block device scan and null_blk > device creation with zoned mode enabled are also modified to require > this feature using the helper blk_queue_required_elevator_features(). > > This requirement can always be satisfied as the mq-deadline scheduler is > always selected for in-kernel compilation when CONFIG_BLK_DEV_ZONED > (zoned block device support) is enabled. Hmm I would have preferred this to be split into two patches, one introducing the features (not just ELEVATOR_F_ZONED_BLOCK_DEV but also the features you describe in 4/7) and mark all schedulers with the feature bits and then one pulling the requirement of ELEVATOR_F_ZONED_BLOCK_DEV in null_blk and sd. -- Johannes Thumshirn SUSE Labs Filesystems jthumshirn@xxxxxxx +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
