On 3/26/23 16:45, Christoph Hellwig wrote:
Exactly. That's why ZONE_APPEND is the only really viable high-level interface.
Using REQ_OP_ZONE_APPEND may lead to reordering - data being written on the storage medium in another order than the order in which the REQ_OP_ZONE_APPEND commands were submitted. Hence, the number of extents for large files increases and performance when reading large files reduces. To me comparing the performance of these two approaches sounds like a good topic for a research paper. I'm not sure that REQ_OP_ZONE_APPEND is better for all zoned storage workloads than REQ_OP_WRITE.
Thanks, Bart.
