On 25/02/2025 22:18, Will Deacon wrote:
On Mon, Feb 24, 2025 at 12:11:19PM +0000, Ryan Roberts wrote:
On 21/02/2025 15:31, Will Deacon wrote:
On Mon, Feb 17, 2025 at 02:04:15PM +0000, Ryan Roberts wrote:
- 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