Changyuan, > Trace events like scsi_dispatch_cmd_start and scsi_dispatch_cmd_done > are useful for tracking a command throughout its lifetime. But for > some ATA passthrough commands, the information printed in current logs > is not enough to identify and match them. For example, if two threads > send SMART cmd to the same disk at the same time, their trace logs may > look the same, which makes it hard to match scsi_dispatch_cmd_done and > scsi_dispatch_cmd_start. Printing tags can help us solve the problem. > Further, if a command failed for some reason and then is retried, its > driver_tag will change. So scheduler_tag is also included such that we > can track the retries of a command. Applied to 5.20/scsi-staging, thanks! -- Martin K. Petersen Oracle Linux Engineering
