Re: solid state drive access and context switching

From: Alan Cox
Date: Tue Dec 04 2007 - 19:29:37 EST


On Tue, 4 Dec 2007 16:08:07 -0800
"Jared Hulbert" <jaredeh@xxxxxxxxx> wrote:

> On Dec 4, 2007 3:24 PM, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:
> > > Right. The trend is to hide the nastiness of NAND technology changes
> > > behind controllers. In general I think this is a good thing.
> >
> > You miss the point - any controller you hide it behind almost inevitably
> > adds enough latency you don't want to use it synchronously.
>
> I think I get it. We keep saying that it's the latency is too high.
> I agree that most technologies out there have latencies that are too
> high. Again I ask the question, what latencies do we have to hit
> before the sync options become worth it?

Probably about 1000 clocks but its always going to depend upon the
workload and whether any other work can be done usefully.

Alan
--
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/