Commit a1bc561b authored by Ohhoon Kwon's avatar Ohhoon Kwon Committed by Linus Torvalds
Browse files

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/20210707150212.855-1-ohoono.kwon@samsung.com
Link: https://lkml.kernel.org/r/20210707150212.855-2-ohoono.kwon@samsung.com


Signed-off-by: default avatarOhhoon Kwon <ohoono.kwon@samsung.com>
Acked-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cdcfc631

mm/sparse.c

+4 −5
Original line number Diff line number Diff line
@@ -187,10 +187,9 @@ void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn, 
 * 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 nid, unsigned long start, unsigned long en 
		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, unsigned long start_pfn, 


	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)