On Fri, Apr 08, 2016 at 01:29:26PM +0200, Hannes Reinecke wrote: > I'd like to propose a topic on block-mq issues with FC. > During my performance testing using block/scsi-mq with FC I've hit > several issues I'd like to discuss: If there's a general block-mq bitching session, I have some ideas :-) - Inability to use all queues supported by a device. Intel's P3700 supports 31 queues, but block-mq insists on assigning an even multiple of CPUs to each queue. So if you have 48 CPUs, it will use 24 queues. If you have 128 CPUs, it will only use 16 of the queues. - Interrupt steering needs to be controlled by block-mq instead of the driver. It's pointless to have each driver implement its own policies on interrupt steering, irqbalanced remains a source of end-user frustration, and block-mq can change the queue<->cpu mapping without the driver's knowledge. (thanks to Keith for his input on the first and suggestion of the second). -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
