On Mon, 2018-04-16 at 20:27 +0000, Bean Huo (beanhuo) wrote: > By the way, these patches are not to add new feature, they are just to > add print tag along with the other exist printed request parameters. Are you aware that there are two tag fields in struct request, namely "tag" and "internal_tag"? Are you aware that how these fields are used depends on whether or not a scheduler is attached to a request queue? Have you verified that the "tag" field contains a meaningful value for blk-mq for every blk-mq tracepoint? Thanks, Bart.