On 03.02.21 11:47, Oscar Salvador wrote:
We never get to allocate 1GB pages when mapping the vmemmap range.
Drop the dead code both for the aligned and unaligned cases and leave
only the direct map handling.
Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
---
arch/x86/mm/init_64.c | 31 ++++---------------------------
1 file changed, 4 insertions(+), 27 deletions(-)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index b0e1d215c83e..28729c6b9775 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1062,7 +1062,6 @@ remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
unsigned long next, pages = 0;
pmd_t *pmd_base;
pud_t *pud;
- void *page_addr;
pud = pud_start + pud_index(addr);
for (; addr < end; addr = next, pud++) {
@@ -1072,32 +1071,10 @@ remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
continue;
if (pud_large(*pud)) {
- if (IS_ALIGNED(addr, PUD_SIZE) &&
- IS_ALIGNED(next, PUD_SIZE)) {
- if (!direct)
- free_pagetable(pud_page(*pud),
- get_order(PUD_SIZE));
-
- spin_lock(&init_mm.page_table_lock);
- pud_clear(pud);
- spin_unlock(&init_mm.page_table_lock);
- pages++;
- } else {
- /* If here, we are freeing vmemmap pages. */
- memset((void *)addr, PAGE_INUSE, next - addr);
-
- page_addr = page_address(pud_page(*pud));
- if (!memchr_inv(page_addr, PAGE_INUSE,
- PUD_SIZE)) {
- free_pagetable(pud_page(*pud),
- get_order(PUD_SIZE));
-
- spin_lock(&init_mm.page_table_lock);
- pud_clear(pud);
- spin_unlock(&init_mm.page_table_lock);
- }
- }
-
+ spin_lock(&init_mm.page_table_lock);
+ pud_clear(pud);
+ spin_unlock(&init_mm.page_table_lock);
+ pages++;
continue;
}
One problem I see with existing code / this change making more obvious
is that when trying to remove in other granularity than we added (e.g.,
unplug a 128MB DIMM avaialble during boot), we remove the direct map of
unrelated DIMMs.
I think we should keep the
if (IS_ALIGNED(addr, PUD_SIZE) &&
IS_ALIGNED(next, PUD_SIZE)) {
...
}
bits. Thoguhts?
Apart from that looks good.
--
Thanks,
David / dhildenb
