Re: [RFC PATCH v4 0/6] Promotion of Unmapped Page Cache Folios.

[Matthew Wilcox]

On Fri, Apr 11, 2025 at 08:09:55PM -0400, Gregory Price wrote:
> On Sat, Apr 12, 2025 at 12:49:18AM +0100, Matthew Wilcox wrote:
> > On Fri, Apr 11, 2025 at 06:11:05PM -0400, Gregory Price wrote:
> > > Unmapped page cache pages can be demoted to low-tier memory, but
> > 
> > No.  Page cache should never be demoted to low-tier memory.
> > NACK this patchset.
> 
> This wasn't a statement of approval page cache being on lower tiers,
> it's a statement of fact.  Enabling demotion causes this issue.

Then that's the bug that needs to be fixed.  Not adding 200+ lines
of code to recover from a situation that should never happen.