@@ -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
