Re: bfq-mq performance comparison to cfq

From: Bart Van Assche
Date: Mon Apr 10 2017 - 11:15:41 EST


On Mon, 2017-04-10 at 11:55 +0200, Paolo Valente wrote:
> That said, if you do always want maximum throughput, even at the
> expense of latency, then just switch off low-latency heuristics, i.e.,
> set low_latency to 0. Depending on the device, setting slice_ilde to
> 0 may help a lot too (as well as with CFQ). If the throughput is
> still low also after forcing BFQ to an only-throughput mode, then you
> hit some bug, and I'll have a little more work to do ...

Hello Paolo,

Has it been considered to make applications tell the I/O scheduler
whether to optimize for latency or for throughput? It shouldn't be that
hard for window managers and shells to figure out whether or not a new
application that is being started is interactive or not. This would
require a mechanism that allows applications to provide such information
to the I/O scheduler. Wouldn't that be a better approach than the I/O
scheduler trying to guess whether or not an application is an interactive
application?

Bart.