@@ -962,7 +962,6 @@ remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end, { unsigned long next, pages = 0; pte_t *pte; - void *page_addr; phys_addr_t phys_addr;pte = pte_start + pte_index(addr);@@ -983,42 +982,19 @@ remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end, if (phys_addr < (phys_addr_t)0x40000000) return;- if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) {- /* - * Do not free direct mapping pages since they were - * freed when offlining, or simplely not in use. - */ - if (!direct) - free_pagetable(pte_page(*pte), 0); - - spin_lock(&init_mm.page_table_lock); - pte_clear(&init_mm, addr, pte); - spin_unlock(&init_mm.page_table_lock); - - /* For non-direct mapping, pages means nothing. */ - pages++; - } else { - /* - * If we are here, we are freeing vmemmap pages since - * direct mapped memory ranges to be freed are aligned. - * - * If we are not removing the whole page, it means - * other page structs in this page are being used and - * we canot remove them. So fill the unused page_structs - * with 0xFD, and remove the page when it is wholly - * filled with 0xFD. - */ - memset((void *)addr, PAGE_INUSE, next - addr); + /* + * Do not free direct mapping pages since they were + * freed when offlining, or simplely not in use. + */
s/simplely/simply/ (I know, not your fault :) )However, that comment is highly confusing. There is nothing to free in case of the a direct mapping; we never allocated anything. That's how a direct map works.
I'd just get rid of the comment completely - we also don't have one at the other "if (!direct)" places.
(side note: all this freeing before unmapping looks very weird, but at least we should have valid accesses anymore)
+ if (!direct) + free_pagetable(pte_page(*pte), 0);
[...]
{
+ /*
+ * See comment in vmemmap_populate().
+ */
I'd drop this comment ...
+ VM_BUG_ON(!IS_ALIGNED(start, PAGE_SIZE)); + VM_BUG_ON(!IS_ALIGNED(end, PAGE_SIZE)); + remove_pagetable(start, end, false, altmap); }@@ -1556,6 +1538,15 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,{ int err;+ /*+ * __populate_section_memmap enforces the range to be added to be + * PMD aligned. Therefore we can be sure that, as long as the + * struct page size is multiple of 8, the vmemmap range will be + * PAGE aligned. + */
... and this comment, moving the details into the patch description.The commit should be easy to detect using git blame in case anybody wonders why.
+ VM_BUG_ON(!IS_ALIGNED(start, PAGE_SIZE)); + VM_BUG_ON(!IS_ALIGNED(end, PAGE_SIZE)); + if (end - start < PAGES_PER_SECTION * sizeof(struct page)) err = vmemmap_populate_basepages(start, end, node, NULL); else if (boot_cpu_has(X86_FEATURE_PSE))
Apart from that looks good, thanks! -- Thanks, David / dhildenb
