+ x86-vmemmap-drop-handling-of-1gb-vmemmap-ranges.patch added to -mm tree

* + x86-vmemmap-drop-handling-of-1gb-vmemmap-ranges.patch added to -mm tree
@ 2021-03-10 22:58 akpm
  0 siblings, 0 replies; 2+ messages in thread
From: akpm @ 2021-03-10 22:58 UTC (permalink / raw)
  To: bp, dave.hansen, david, hpa, luto, mhocko, mingo, mm-commits,
	osalvador, peterz, tglx, ziy


The patch titled
     Subject: x86/vmemmap: drop handling of 1GB vmemmap ranges
has been added to the -mm tree.  Its filename is
     x86-vmemmap-drop-handling-of-1gb-vmemmap-ranges.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/x86-vmemmap-drop-handling-of-1gb-vmemmap-ranges.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/x86-vmemmap-drop-handling-of-1gb-vmemmap-ranges.patch

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------------------------------------------------------
From: Oscar Salvador <osalvador@suse.de>
Subject: x86/vmemmap: drop handling of 1GB vmemmap ranges

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.

Link: https://lkml.kernel.org/r/20210309214050.4674-3-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/mm/init_64.c |   35 +++++++----------------------------
 1 file changed, 7 insertions(+), 28 deletions(-)

--- a/arch/x86/mm/init_64.c~x86-vmemmap-drop-handling-of-1gb-vmemmap-ranges
+++ a/arch/x86/mm/init_64.c
@@ -1062,7 +1062,6 @@ remove_pud_table(pud_t *pud_start, unsig
 	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, unsig
 		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;
 		}
 
_

Patches currently in -mm which might be from osalvador@suse.de are

x86-vmemmap-drop-handling-of-4k-unaligned-vmemmap-range.patch
x86-vmemmap-drop-handling-of-1gb-vmemmap-ranges.patch
x86-vmemmap-handle-unpopulated-sub-pmd-ranges.patch
x86-vmemmap-optimize-for-consecutive-sections-in-partial-populated-pmds.patch


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