linux-kernel - Re: [RFC PATCH 05/12] fs/proc/task_mmu: refactor pagemap_pmd

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Message-ID: <20251027161146.GG760669@ziepe.ca>
Date: Mon, 27 Oct 2025 13:11:46 -0300
From: Jason Gunthorpe <jgg@...pe.ca>
To: Gregory Price <gourry@...rry.net>
Cc: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Christian Borntraeger <borntraeger@...ux.ibm.com>,
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Subject: Re: [RFC PATCH 05/12] fs/proc/task_mmu: refactor pagemap_pmd_range()

On Fri, Oct 24, 2025 at 04:37:18PM -0400, Gregory Price wrote:
> On Fri, Oct 24, 2025 at 09:15:59PM +0100, Lorenzo Stoakes wrote:
> > On Fri, Oct 24, 2025 at 03:12:08PM -0400, Gregory Price wrote:
> > 
> > So maybe actually that isn't too bad of an idea...
> > 
> > Could also be
> > 
> > nonpresent_or_swap_t but that's kinda icky...
> 
> clearly we need:
> 
> union {
> 	swp_entry_t swap;
> 	nonpresent_entry_t np;
> 	pony_entry_t pony;
> 	plum_emtry_t beer;
> } leaf_entry_t;
> 
> with
> 
> leaf_type whats_that_pte(leaf_entry_t);

I think if you are going to try to rename swp_entry_t that is a pretty
good idea. Maybe swleaf_entry_t to pace emphasis that it is not used
by the HW page table walker would be a good compromise to the ugly
'non-present entry' term.

Jason