Re: [PATCH 0/3] resource: find_next_iomem_res() improvements

From: Andrew Morton
Date: Tue Jul 16 2019 - 18:00:51 EST


On Tue, 18 Jun 2019 21:56:43 +0000 Nadav Amit <namit@xxxxxxxxxx> wrote:

> > ...and is constant for the life of the device and all subsequent mappings.
> >
> >> Perhaps you want to cache the cachability-mode in vma->vm_page_prot (which I
> >> see being done in quite a few cases), but I donât know the code well enough
> >> to be certain that every vma should have a single protection and that it
> >> should not change afterwards.
> >
> > No, I'm thinking this would naturally fit as a property hanging off a
> > 'struct dax_device', and then create a version of vmf_insert_mixed()
> > and vmf_insert_pfn_pmd() that bypass track_pfn_insert() to insert that
> > saved value.
>
> Thanks for the detailed explanation. Iâll give it a try (the moment I find
> some free time). I still think that patch 2/3 is beneficial, but based on
> your feedback, patch 3/3 should be dropped.

It has been a while. What should we do with

resource-fix-locking-in-find_next_iomem_res.patch
resource-avoid-unnecessary-lookups-in-find_next_iomem_res.patch

?