Hi I'd like to discuss the ongoing work in the kernel to enable high priority IO via polling for completion in the blk-mq subsystem. Given that iopoll only really makes sense for low-latency, low queue depth environments (i.e. down below 10-20us) I'd like to discuss which drivers we think will need/want to be upgraded (aside from NVMe ;-)). I'd also be interested in discussing how best to enable and disable polling. In the past some of us have pushed for a "big hammer" to turn polling on for a given device or HW queue [1]. I'd like to discuss this again as well as looking at other methods above and beyond the preadv2 system call and the HIPRI flag. Finally I'd like to discuss some of the recent work to improve the heuristics around when to poll and when not to poll. I'd like to see if we can come up with more optimal balance between CPU load and average completion times [2]. Stephen Bates [1] http://marc.info/?l=linux-block&m=146307410101827&w=2 [2] http://marc.info/?l=linux-block&m=147803441801858&w=2 -- 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
