On 26.09.24 13:40, Jason Gunthorpe wrote:
On Thu, Sep 26, 2024 at 01:32:09PM +0200, David Hildenbrand wrote:
On 20.09.24 15:28, Jason Gunthorpe wrote:
On Thu, Sep 19, 2024 at 10:11:38AM +0200, David Hildenbrand wrote:
And repin is really misleading. We are simply adding more pins to an already pinned one ...
Jason suggests a better name in the other thread.
I would prefer something that simply adds more pins to an already pinned
folio. Much easier to get.
Yes, but also nobody should ever want to do that operation, it should
always be part of some kind of "splitting" sort of behavior..
I remember patches from Dave Howells that needed that for O_DIRECT handling.
Never say never ;)
Wouldn't O_DIRECT be the same splitting thing?
No, I recall the implementation had to duplicate pins, not split.
Adding is much more intuitive than splitting ... just like we add references
when splitting a THP, using folio_ref_add().
Well, sure, it just seems harder to document so people can use it
properly.
As soon as we have large GUP and splitting might go to multiple PMDs,
multiple PTEs or a mixture, just being able to add the number of pins
you actually need might be cleaner ...
Let me have a look at the latest reincarnation of this patch.
--
Cheers,
David / dhildenb
