On 1/4/2023 4:57 PM, Jane Chu wrote:
+ * @stop_at_none determines what we do when we encounter an empty
PTE. If true,
+ * we return that PTE. If false and @sz is less than the current
PTE's size,
+ * we make that PTE point to the next level down, going until @sz is
the same
+ * as our current PTE.
[..]
+int hugetlb_hgm_walk(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct hugetlb_pte *hpte, unsigned long addr,
+ unsigned long sz, bool stop_at_none)
+{
Also here below, the way 'stop_at_none' is used when HGM isn't enabled
is puzzling. Could you elaborate please?
+ if (!hugetlb_hgm_enabled(vma)) {
+ if (stop_at_none)
+ return 0;
+ return sz == huge_page_size(hstate_vma(vma)) ? 0 : -EINVAL;
+ }
[..]
+ while (hugetlb_pte_size(hpte) > sz && !ret) {
+ pte = huge_ptep_get(hpte->ptep);
+ if (!pte_present(pte)) {
+ if (stop_at_none)
+ return 0;
+ if (unlikely(!huge_pte_none(pte)))
+ return -EEXIST;
If 'stop_at_none' means settling down on the just encountered empty PTE,
should the above two "if" clauses switch order? I thought Peter has
raised this question too, but I'm not seeing a response.
Regards,
-jane
+ } else if (hugetlb_pte_present_leaf(hpte, pte))
+ return 0;
+ ret = hugetlb_walk_step(mm, hpte, addr, sz);
+ }
+
+ return ret;
+}
+
thanks,
-jane
