Re: 2.6.22-rc4-mm1

KAMEZAWA Hiroyuki
2007-06-07T12:46:25Z

Question.

While writing memory unplug, I noticed this code.
==
static int
fixup_anon_page(pte_t *pte, unsigned long start, unsigned long end, void *priv)
{
struct vm_area_struct *vma = priv;
struct page *page = vm_normal_page(vma, start, *pte);

if (page && PageAnon(page))
page->index = linear_page_index(vma, start);

return 0;
}

static int fixup_anon_pages(struct vm_area_struct *vma)
{
struct mm_walk walk = {
.pte_entry = fixup_anon_page,
};

return walk_page_range(vma->vm_mm,
vma->vm_start, vma->vm_end, &walk, vma);
}
==

I think that 'pte' passed to fixup_anon_page() by walk_page_range()
is not guaranteed to be 'Present'.

Then, vm_normal_page() will show print_bad_pte().

If this never occur now, I'll add my own check code for memory migration by kernel here.

(Sorry, I can't find who should be CCed.)

-Kame