Re: [PATCH RFC] blkcg: prepare blkcg knobs for default hierarchy

From: Tejun Heo
Date: Wed Apr 23 2014 - 15:01:05 EST


Hello,

On Wed, Apr 23, 2014 at 02:58:35PM -0400, Vivek Goyal wrote:
> Oh, sorry, I had misunderstood your question.
>
> - Number of IOs serviced will be different at throttling layer and
> CFQ layer as throttling accounts IO in terms of bios and CFQ
> accounts in terms of number of requests.

But shouldn't it be possible to determine that from merged count? Or
we can just expose both bio and request counts at block core layer.
The point is that there's nothing controller specific about these
stats.

> - CFQ might not be operational on a device while throttling might be
> on and one needs bytes stats.

Yeah, so expose both from blkcg core as blkio.* stats.

> - In a custom kernel throttling might not be on and CFQ is on and
> one needs the stats.

Ditto.

Thanks.

--
tejun
--
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/