Re: [00/17] Large Blocksize Support V3

Mel Gorman
2007-04-26T20:22:20Z

On (26/04/07 20:39), Jens Axboe didst pronounce:
> On Thu, Apr 26 2007, Christoph Lameter wrote:
> > On Thu, 26 Apr 2007, Jens Axboe wrote:
> >
> > > On Thu, Apr 26 2007, Christoph Lameter wrote:
> > > > On Thu, 26 Apr 2007, Jens Axboe wrote:
> > > >
> > > > > The above can be implemented fairly cleanly, and on a need-to-have
> > > > > basis. It's not something that'll break drivers.
> > > >
> > > > But its also not going to fix the hacks that we have in the kernel
> > > > to deal with > PAGE_SIZE i/o.
> > >
> > > No, but that's a _seperate_ issue! Don't keep mixing up the two.
> >
> > Yes I understand that you want it to be a separate issue so we get get
> > more rationales for the hacks that we do to avoid the large
> > order allocations.
>
> Christoph, don't take your frustrations out on me. I've several times in
> this thread said that I'd LIKE to have > PAGE_SIZE support in the page
> cache. I WROTE the initial pktcdvd driver that is a primary example of
> these hacks, I'm very well aware of the pain and bugs involved with
> that.
>
> But don't push large pages as the only solution to larger ios, because
> that is trivially not true.
>

Would it be fair to say that your approach and using large pages are not
mutually exclusive solutions? It seems a lot of the debate here is
assuming there is One And Only One Solution for larger ios.

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab