__munlock_pagevec

/*
 * Fill up pagevec for __munlock_pagevec using pte walk
 *
 * The function expects that the struct page corresponding to @start address is
 * a non-TPH page already pinned and in the @pvec, and that it belongs to @zone.
 *
 * The rest of @pvec is filled by subsequent pages within the same pmd and same
 * zone, as long as the pte's are present and vm_normal_page() succeeds. These
 * pages also get pinned.
 *
 * Returns the address of the next page that should be scanned. This equals
 * @start + PAGE_SIZE when no page could be added by the pte walk.
 */
static unsigned long __munlock_pagevec_fill(struct pagevec *pvec,
            struct vm_area_struct *vma, struct zone *zone,
            unsigned long start, unsigned long end)
{
    pte_t *pte;
    spinlock_t *ptl;
 
    /*
     * Initialize pte walk starting at the already pinned page where we
     * are sure that there is a pte, as it was pinned under the same
     * mmap_sem write op.
     */
    pte = get_locked_pte(vma->vm_mm, start, &ptl);
    /* Make sure we do not cross the page table boundary */
    end = pgd_addr_end(start, end);
    end = p4d_addr_end(start, end);
    end = pud_addr_end(start, end);
    end = pmd_addr_end(start, end);
 
    /* The page next to the pinned page is the first we will try to get */
    start += PAGE_SIZE;
    while (start < end) {
        struct page *page = NULL;
        pte++;
        if (pte_present(*pte))
            page = vm_normal_page(vma, start, *pte);
        /*
         * Break if page could not be obtained or the page's node+zone does not
         * match
         */
        if (!page || page_zone(page) != zone)
            break;
 
        /*
         * Do not use pagevec for PTE-mapped THP,
         * munlock_vma_pages_range() will handle them.
         */
        if (PageTransCompound(page))
            break;
 
        get_page(page);
        /*
         * Increase the address that will be returned *before* the
         * eventual break due to pvec becoming full by adding the page
         */
        start += PAGE_SIZE;
        if (pagevec_add(pvec, page) == 0)
            break;
    }
    pte_unmap_unlock(pte, ptl);
    return start;
}
函数源码
