Re: [PATCH 03/33] mm: Implement readahead_control pageset expansion

Mike Marshall
2021-02-17T16:59:29Z

Matthew has looked at how I'm fumbling about
trying to deal with Orangefs's need for much larger
than page-sized IO...

I think I need to implement orangefs_readahead
and from there fire off an asynchronous read
and while that's going I'll call readahead_page
with a rac that I've cranked up with readahead_expand
and when the read gets done I'll have plenty of pages
for the large IO I did.

Even if what I think I need to do is somewhere
near right, the async code in the Orangefs
kernel module didn't make it into the upstream
version, so I have to refurbish that. All that to
say: I don't need readahead_expand
"tomorrow", but it fits into my plan to
get Orangefs the extra pages it needs
without me having open-coded page cache
code in orangefs_readpage.

-Mike

On Wed, Feb 17, 2021 at 10:42 AM David Howells <dhowells@redhat.com> wrote:
>
> Mike Marshall <hubcap@omnibond.com> wrote:
>
> > I plan to try and use readahead_expand in Orangefs...
>
> Would it help if I shuffled the readahead_expand patch to the bottom of the
> pack?
>
> David
>