Ming,
> Since supporting to blk-mq, big pre-allocation for sg list is > introduced, this way is very unfriendly wrt. memory consumption. Applied to 5.3/scsi-queue with some clarifications to the commit descriptions. I am not entirely sold on 1 for the inline protection SGL size. NVMe over PCIe is pretty constrained thanks to the metadata pointer whereas SCSI DIX uses a real SGL for the PI. Consequently, straddling a page is not that uncommon for large, sequential I/Os. But let's try it out. If performance suffers substantially, we may want to bump it to 2. -- Martin K. Petersen Oracle Linux Engineering
