On 26/10/22 10:30, Christian Löhle wrote: > Mmcblk relies on block layer requeueing to fulfill some requests under > certain conditions. Improve the handling to get nicely ordered requests. > > Using the terms a bit loosely to get a point across: > Current behavior for 512 blksz and max_blk_count = 1 the scenario would > be as follows: > > - request for page 0 lba 0 to 7 > - request for page 1 lba 8 to 15 > - request for page 2 lba 16 to 23 > - request for page 3 lba 24 to 31 > > mmcblk modifies data->blocks = 1 for each and requeues, > this leads to: > > Access lba 0 > Access lba 8 > Access lba 16 > Access lba 24 > Access lba 1 (1. Requeue for page 0) > Access lba 9 (1. Requeue for page 1) > Access lba 17 (1. Requeue for page 2) > Access lba 25 (1. Requeue for page 3) > Access lba 2 (2. Requeue for page 0) > ... > > Of course we would rather have lbas consecutive. Does anyone know why the block layer does not support (max_hw_sectors << 9) < PAGE_SIZE ?
