Re: Bandwidth Allocations under CFQ I/O Scheduler

[Helge Hafting]

Jens Axboe wrote:
> While that may make some sense internally, the exported interface would
> never be workable like that. It needs to be simple, "give me foo kb/sec
> with max latency bar for this file", with an access pattern or assumed
> sequential io.
>
> Nobody speaks of iops/sec except some silly benchmark programs. I know
> that you are describing pseudo-iops, but it still doesn't make it more
> clear.
> Things aren't as simple
>   
How about "give me 10% of total io capacity?"  People understand
this, and the io scheduler can then guarantee this by ensuring
that the process gets 1 out of 10 io requests as long as it
keeps submitting enough.

The admin can then set a reasonable percentage depending on
the machine's capacity.

Helge Hafting
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/