From: Ohhoon Kwon <ohoono.kwon@samsung.com>
To: david@redhat.com, ohoono.kwon@samsung.com,
akpm@linux-foundation.org, mhocko@suse.com
Cc: bhe@redhat.com, rppt@linux.ibm.com, ohkwon1043@gmail.com,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 1/3] mm: sparse: pass section_nr to section_mark_present
Date: Mon, 5 Jul 2021 17:55:36 +0900 [thread overview]
Message-ID: <20210705085538.14557-2-ohoono.kwon@samsung.com> (raw)
In-Reply-To: <20210705085538.14557-1-ohoono.kwon@samsung.com>
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.
On the other hand, __nr_to_section() which converts section_nr to
mem_section can be done in O(1).
Let's pass section_nr instead of mem_section ptr to
section_mark_present() in order to reduce needless iterations.
Signed-off-by: Ohhoon Kwon <ohoono.kwon@samsung.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
---
mm/sparse.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/mm/sparse.c b/mm/sparse.c
index 6326cdf36c4f..b4fae2fc6276 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -187,13 +187,14 @@ 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(unsigned long section_nr)
{
- unsigned long section_nr = __section_nr(ms);
+ struct mem_section *ms;
if (section_nr > __highest_present_section_nr)
__highest_present_section_nr = section_nr;
+ ms = __nr_to_section(section_nr);
ms->section_mem_map |= SECTION_MARKED_PRESENT;
}
@@ -280,7 +281,7 @@ 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(section);
}
}
}
@@ -934,7 +935,7 @@ 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(section_nr);
/* Align memmap to section boundary in the subsection case */
if (section_nr_to_pfn(section_nr) != start_pfn)
--
2.17.1
next prev parent reply other threads:[~2021-07-05 8:59 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20210705085918epcas1p1493a3b289b3144bf86e90893185c088a@epcas1p1.samsung.com>
2021-07-05 8:55 ` [PATCH v2 0/3] mm: sparse: remove __section_nr() function Ohhoon Kwon
[not found] ` <CGME20210705085918epcas1p17e0ac84d91c591897d00fbc3d3caa771@epcas1p1.samsung.com>
2021-07-05 8:55 ` Ohhoon Kwon [this message]
2021-07-07 9:12 ` [PATCH v2 1/3] mm: sparse: pass section_nr to section_mark_present Michal Hocko
[not found] ` <CGME20210705085918epcas1p3fdaf2bc0de2f1017c3057aeb6e8c82a7@epcas1p3.samsung.com>
2021-07-05 8:55 ` [PATCH v2 2/3] mm: sparse: pass section_nr to find_memory_block Ohhoon Kwon
[not found] ` <CGME20210705085918epcas1p415e226a85dc289c2d306c009dbc4ef55@epcas1p4.samsung.com>
2021-07-05 8:55 ` [PATCH v2 3/3] mm: sparse: remove __section_nr() function Ohhoon Kwon
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