On 01/19/2017 11:57 AM, Ming Lei wrote: > On Wed, Jan 11, 2017 at 11:07 PM, Jens Axboe <ax...@kernel.dk> wrote: >> On 01/11/2017 06:43 AM, Johannes Thumshirn wrote: >>> Hi all, >>> >>> I'd like to attend LSF/MM and would like to discuss polling for block >>> drivers. >>> >>> Currently there is blk-iopoll but it is neither as widely used as NAPI in >>> the >>> networking field and accoring to Sagi's findings in [1] performance with >>> polling is not on par with IRQ usage. >>> >>> On LSF/MM I'd like to whether it is desirable to have NAPI like polling in >>> more block drivers and how to overcome the currently seen performance >>> issues. >> >> It would be an interesting topic to discuss, as it is a shame that blk-iopoll >> isn't used more widely. > > I remembered that Keith and I discussed some issues of blk-iopoll: > > http://marc.info/?l=linux-block&m=147576999016407&w=2 > > seems which isn't addressed yet. > That's a different poll.
For some obscure reasons you have a blk-mq-poll function (via q->mq_ops->poll) and an irqpoll function. The former is for polling completion of individual block-layer tags, the latter for polling completions from the hardware instead of relying on interrupts. We're discussing the latter here, so that thread isn't really applicable here. However, there have been requests to discuss the former at LSF/MM, too. So there might be a chance of restarting that discussion. Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking h...@suse.de +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-block" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
