Re: Linux 2.6.29

Hugh Dickins
2009-03-26T19:06:21Z

On Thu, 26 Mar 2009, Jens Axboe wrote:
> On Thu, Mar 26 2009, Hugh Dickins wrote:
> >
> > So, directing a barrier (WRITE_BARRIER or DISCARD_BARRIER) to a range
> > of sectors in one partition interposes a barrier into the queue of I/O
> > across (all partitions of) that whole device.
>
> Correct
>
> > I think that's not how filesystems really want barriers to behave,
> > and might tend to discourage us from using barriers more freely.
> > But I have zero appreciation of whether it's a significant issue
> > worth non-trivial change - just wanted to get it out into the open.
>
> Per-partition definitely makes sense. The problem is that we do sorting
> on a per-device basis right now. But it's a good point, I'll try and
> take a look at how much work it would be to make it per-partition
> instead. It wont be trivial :-)

Thanks, that would be interesting.
Trivial bores you anyway, doesn't it?

Hugh