Re: [PATCHSET v6 0/12] Uncached buffered IO

Johannes Weiner
2024-12-13T05:04:17Z

On Thu, Dec 12, 2024 at 07:35:28PM +0000, Matthew Wilcox wrote:
> On Thu, Dec 12, 2024 at 12:14:23PM -0700, Jens Axboe wrote:
> > Like I mentioned earlier, the fact that it's cached for the duration of
> > the operation is more of an implementation detail that developers need
> > not worry about. What's important is that it's not cached AFTER. I still
> > feel UNCACHED is the best description, but I'll change it to DONTCACHE
> > for the next version just to avoid the overlap with other in-kernel
> > uses.
>
> Regardless of the user API name, I like PG_streaming for the folio
> flag name.

If we're throwing names in the ring, I'm partial to PG_dropbehind.

It's a term I think has been used to describe this type of behavior
before; it juxtaposes nicely with readahead; it plainly names the
action of what will happen to the page after the current IO operation
against it has completed (i.e. pairs up with PG_reclaim).