Re: [PATCH v5 05/78] xarray: Replace exceptional entries

From: Kirill A. Shutemov
Date: Wed Dec 27 2017 - 05:24:52 EST


On Tue, Dec 26, 2017 at 07:05:34PM -0800, Matthew Wilcox wrote:
> On Tue, Dec 26, 2017 at 08:15:42PM +0300, Kirill A. Shutemov wrote:
> > > 28 files changed, 249 insertions(+), 240 deletions(-)
> >
> > Everything looks fine to me after quick scan, but hat's a lot of changes for
> > one patch...
>
> Yeah. It's pretty mechanical though.
>
> > > - if (radix_tree_exceptional_entry(page)) {
> > > + if (xa_is_value(page)) {
> > > if (!invalidate_exceptional_entry2(mapping,
> > > index, page))
> > > ret = -EBUSY;
> >
> > invalidate_exceptional_entry? Are we going to leave the terminology here as is?
>
> That is a great question. If the page cache wants to call its value
> entries exceptional entries, it can continue to do that. I think there's
> a better name for them, but I'm not sure what it is. Right now, the
> page cache uses value entries to store:
>
> 1. Shadow entries (for workingset)
> 2. Swap entries (for shmem)
> 3. DAX entries
>
> I can't come up with a good name for these three things. 'nonpage' is
> the only thing which hasn't immediately fallen off my ideas list.

Yeah, naming problem...

> But I think renaming exceptional entries in the page cache is a great idea,
> and I don't want to do it as part of this patch set ;-)

Fair enough.

--
Kirill A. Shutemov