On 07/28/2016 05:40 PM, Mike Snitzer wrote: > On Thu, Jul 28 2016 at 11:23am -0400, > Bart Van Assche <bart.vanassche@xxxxxxxxxxx> wrote: > >> On 07/28/2016 06:33 AM, Mike Snitzer wrote: [ .. ] > > Reality is I just need a testbed to reproduce. This back and forth > isn't really helping us converge on _why_ must_push_back() is returning > false for your case. I need to know what exactly is causing that method > to return false in your case. > > As is, hard to see why blk-mq vs .request_fn interface for DM mpath > device would cause must_push_back() to return false vs true. > I wonder if that isn't the same issue I've seen (and tried to discuss at LSF), hitting the printk in blk_cloned_rq_check_limits(). If I would hazard a guess I'd say that the queue limits become temporarily invalidated during failover, and we're managing to submit an I/O at just that time. I am currently working on getting FCoE to run over virtio; if that works we should be a good synthetic testbed for reproducing. Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
