Blk-mq Is Almost Feature Complete & Fast With Linux 3.16

[axboe]

3.13 had a perf regression as a result of the blk-mq patch, I wonder if this is finally going to be fixed in 3.16?

What perf regression?

[Caleb]

3.13 had a perf regression as a result of the blk-mq patch, I wonder if this is finally going to be fixed in 3.16?

[Rexilion]

I've been sticking with the 3.12.x longterm kernel, because of assorted issues and instability since the multi-queue block layer implementation. Maybe 3.16 will be the one that finally lets me move forward again.

Could you perhaps describe these kind of issue's? I have been issue's on btrfs filesystems with kernel 3.13 or higher. Reading some files causes the process to stall.

[tomtomme]

is it used by default or do I have to set something in /etc/fstab or so?
is it used by default for ssd only? or also for hdd?

[macemoneta]

I've been sticking with the 3.12.x longterm kernel, because of assorted issues and instability since the multi-queue block layer implementation. Maybe 3.16 will be the one that finally lets me move forward again.

[phoronix]

Phoronix: Blk-mq Is Almost Feature Complete & Fast With Linux 3.16

Merged for the Linux 3.13 kernel was the multi-queue block layer allows for better SSD performance with reduced latency and by balancing I/O workload across multiple CPU cores and supporting multiple hardware queues. With the upcoming Linux 3.16 kernel, the "blk-mq" code is expected to be feature complete and deliver great performance...

http://www.phoronix.com/vr.php?view=MTcwNzc