On 25/02/2025 22:18, Will Deacon wrote:

On Mon, Feb 24, 2025 at 12:11:19PM +0000, Ryan Roberts wrote:

quoted

On 21/02/2025 15:31, Will Deacon wrote:

quoted

On Mon, Feb 17, 2025 at 02:04:15PM +0000, Ryan Roberts wrote:

quoted

+	pte = __ptep_get_and_clear(mm, addr, ptep);
+	present = pte_present(pte);
+	while (--ncontig) {
+		ptep++;
+		addr += pgsize;
+		tmp_pte = __ptep_get_and_clear(mm, addr, ptep);
+		if (present) {
+			if (pte_dirty(tmp_pte))
+				pte = pte_mkdirty(pte);
+			if (pte_young(tmp_pte))
+				pte = pte_mkyoung(pte);
+		}
 	}

nit: With the loop now structured like this, we really can't handle
num_contig_ptes() returning 0 if it gets an unknown size. Granted, that
really shouldn't happen, but perhaps it would be better to add a 'default'
case with a WARN() to num_contig_ptes() and then add an early return here?

Looking at other users of num_contig_ptes() it looks like huge_ptep_get()
already assumes at least 1 pte (it calls __ptep_get() before calling
num_contig_ptes()) and set_huge_pte_at() assumes 1 pte for the "present and
non-contig" case. So num_contig_ptes() returning 0 is already not really
consumed consistently.

How about we change the default num_contig_ptes() return value to 1 and add a
warning if size is invalid:

Fine by me!

I assume you'll fold that in and send a new version, along with the typo
fixes?

Yep, I'll aim to post this today. I have a few review comments for s390 to add
in too.

Cheers,

Will