On Wed, Feb 08, 2023 at 11:38:48AM +0300, Kirill A. Shutemov wrote:
> > +static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
> > + pte_t *ptep, pte_t pte, unsigned int nr)
> > +{
> > + for (;;) {
> > + set_pte_at(mm, addr, ptep, pte);
> > + if (--nr == 0)
> > + break;
>
> Maybe do { ... } while (--nr); instead of the for()?
Seems unnecessary to do the extra calculation to advance pte if
we're not going to use it?
> > + ptep++;
> > + addr += PAGE_SIZE;
> > + /* This works for x86. Check how PTEs are encoded */
> > + pte = __pte(pte_val(pte) + PAGE_SIZE);
>
> Looks like it deserves own helper. Something like
>
> pte = pte_next(pte);
Maybe, but then it needs to be added to each arch, which I was trying
to avoid. That said, I had another idea which I like better; more
patches coming soon. Here's a sneak preview:
+++ b/arch/x86/include/asm/pgtable.h
@@ -1019,13 +1019,22 @@ static inline pud_t native_local_pudp_get_and_clear(pud_
t *pudp)
return res;
}
-static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte)
+static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, unsigned int nr)
{
- page_table_check_ptes_set(mm, addr, ptep, pte, 1);
- set_pte(ptep, pte);
+ page_table_check_ptes_set(mm, addr, ptep, pte, nr);
+
+ for (;;) {
+ set_pte(ptep, pte);
+ if (--nr == 0)
+ break;
+ ptep++;
+ pte = __pte(pte_val(pte) + PAGE_SIZE);
+ }
}
+#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
+
static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
