Il giorno 02/nov/2015, alle ore 17:25, Jens Axboe <ax...@fb.com> ha scritto:
> On 11/02/2015 07:31 AM, Paolo Valente wrote: >> From: Arianna Avanzini <avanz...@google.com> >> >> In single-queue (block layer) mode,the function null_rq_prep_fn stops >> the device if alloc_cmd fails. Then, once stopped, the device must be >> restarted on the next command completion, so that the request(s) for >> which alloc_cmd failed can be requeued. Otherwise the device hangs. >> >> Unfortunately, device restart is currently performed only for delayed >> completions, i.e., in irqmode==2. This fact causes hangs, for the >> above reasons, with the other irqmodes in combination with single-queue >> block layer. >> >> This commits addresses this issue by making sure that, if stopped, the >> device is properly restarted for all irqmodes on completions. > > This looks good. I did a double take at the removal of the q->mq_ops check > before blk_queue_stopped(), but we can't get there in MQ mode. Perhaps a > comment would be warranted for that, the ->mq_ops check served as a bit of > documentation for that before. > Honestly, I removed that additional check by mistake. I will put it back in the next version of this patchset, once (and if) I have the green light on patch 1/3. Thanks, Paolo > -- > Jens Axboe > -- Paolo Valente Algogroup Dipartimento di Fisica, Informatica e Matematica Via Campi, 213/B 41125 Modena - Italy homepage: http://algogroup.unimore.it/people/paolo/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
