[PATCH v6 2/4] x86/vmemmap: Drop handling of 1GB vmemmap ranges

From: Oscar Salvador
Date: Tue Mar 09 2021 - 16:41:52 EST


There is no code to allocate 1GB pages when mapping the vmemmap range
as this might waste some memory and requires more complexity which
is not really worth.
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>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
---
arch/x86/mm/init_64.c | 35 +++++++----------------------------
1 file changed, 7 insertions(+), 28 deletions(-)

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index b0e1d215c83e..9ecb3c488ac8 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++) {
@@ -1071,33 +1070,13 @@ remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
if (!pud_present(*pud))
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);
- }
- }
-
+ if (pud_large(*pud) &&
+ IS_ALIGNED(addr, PUD_SIZE) &&
+ IS_ALIGNED(next, PUD_SIZE)) {
+ spin_lock(&init_mm.page_table_lock);
+ pud_clear(pud);
+ spin_unlock(&init_mm.page_table_lock);
+ pages++;
continue;
}

--
2.16.3