Re: [RFC] writeback and cgroup

[Vivek Goyal]

On Tue, Apr 17, 2012 at 02:48:31PM -0700, Tejun Heo wrote:
[..]

> As for priority inversion through shared request pool, it is a problem
> which needs to be solved regardless of how async IOs are throttled.
> I'm not determined to which extent yet tho.  Different cgroups
> definitely need to be on separate pools but do we also want
> distinguish sync and async and what about ioprio?  Maybe we need a
> bybrid approach with larger common pool and reserved ones for each
> class?

currently we have global pool with separate limits for sync and async
and there is no consideration of ioprio. I think to keep it simple we
can just extend the same notion to keep per cgroup pool with internal
limits on sync/async requests to make sure sync IO does not get
serialized behind async IO. Personally I am not too worried about
async IO prio. It has never worked.

Thanks
Vivek
--
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/