[131/212] mm: sparse: pass section_nr to section_mark_present

Commit Message

Andrew Morton Sept. 2, 2021, 9:56 p.m. UTC

From: Ohhoon Kwon <[e-mail]>
Subject: mm: sparse: pass section_nr to section_mark_present

Patch series "mm: sparse: remove __section_nr() function", v4.


This patch (of 3):

With CONFIG_SPARSEMEM_EXTREME enabled, __section_nr() which converts
mem_section to section_nr could be costly since it iterates all section
roots to check if the given mem_section is in its range.

Since both callers of section_mark_present already know section_nr, let's
also pass section_nr as well as mem_section in order to reduce costly
translation.

Link: https://lkml.kernel.org/r/[e-mail]
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ohhoon Kwon <[e-mail]>
Acked-by: Mike Rapoport <[e-mail]>
Acked-by: Michal Hocko <[e-mail]>
Reviewed-by: David Hildenbrand <[e-mail]>
Cc: Baoquan He <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/sparse.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Patch

--- a/mm/sparse.c~mm-sparse-pass-section_nr-to-section_mark_present
+++ a/mm/sparse.c
@@ -187,10 +187,9 @@  void __meminit mminit_validate_memmodel_
  * those loops early.
  */
 unsigned long __highest_present_section_nr;
-static void section_mark_present(struct mem_section *ms)
+static void __section_mark_present(struct mem_section *ms,
+		unsigned long section_nr)
 {
-	unsigned long section_nr = __section_nr(ms);
-
 	if (section_nr > __highest_present_section_nr)
 		__highest_present_section_nr = section_nr;
 
@@ -280,7 +279,7 @@  static void __init memory_present(int ni
 		if (!ms->section_mem_map) {
 			ms->section_mem_map = sparse_encode_early_nid(nid) |
 							SECTION_IS_ONLINE;
-			section_mark_present(ms);
+			__section_mark_present(ms, section);
 		}
 	}
 }
@@ -934,7 +933,7 @@  int __meminit sparse_add_section(int nid
 
 	ms = __nr_to_section(section_nr);
 	set_section_nid(section_nr, nid);
-	section_mark_present(ms);
+	__section_mark_present(ms, section_nr);
 
 	/* Align memmap to section boundary in the subsection case */
 	if (section_nr_to_pfn(section_nr) != start_pfn)