From: Wei Yang <richard.weiyang@linux.alibaba.com>
To: dan.j.williams@intel.com, akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Wei Yang <richard.weiyang@linux.alibaba.com>
Subject: [PATCH] mm/sparse: only sub-section aligned range would be populated
Date: Tue, 30 Jun 2020 10:14:36 +0800 [thread overview]
Message-ID: <20200630021436.43281-1-richard.weiyang@linux.alibaba.com> (raw)
There are two code path which invoke __populate_section_memmap()
* sparse_init_nid()
* sparse_add_section()
For both case, we are sure the memory range is sub-section aligned.
* we pass PAGES_PER_SECTION to sparse_init_nid()
* we check range by check_pfn_span() before calling
sparse_add_section()
Also, the counterpart of __populate_section_memmap(), we don't do such
calculation and check since the range is checked by check_pfn_span() in
__remove_pages().
Clear the calculation and check to keep it simple and comply with its
counterpart.
Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
---
mm/sparse-vmemmap.c | 16 ++--------------
1 file changed, 2 insertions(+), 14 deletions(-)
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index 0db7738d76e9..24b01ebae111 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -247,20 +247,8 @@ int __meminit vmemmap_populate_basepages(unsigned long start,
struct page * __meminit __populate_section_memmap(unsigned long pfn,
unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
{
- unsigned long start;
- unsigned long end;
-
- /*
- * The minimum granularity of memmap extensions is
- * PAGES_PER_SUBSECTION as allocations are tracked in the
- * 'subsection_map' bitmap of the section.
- */
- end = ALIGN(pfn + nr_pages, PAGES_PER_SUBSECTION);
- pfn &= PAGE_SUBSECTION_MASK;
- nr_pages = end - pfn;
-
- start = (unsigned long) pfn_to_page(pfn);
- end = start + nr_pages * sizeof(struct page);
+ unsigned long start = (unsigned long) pfn_to_page(pfn);
+ unsigned long end = start + nr_pages * sizeof(struct page);
if (vmemmap_populate(start, end, nid, altmap))
return NULL;
--
2.20.1 (Apple Git-117)
next reply other threads:[~2020-06-30 2:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-30 2:14 Wei Yang [this message]
2020-06-30 12:52 ` [PATCH] mm/sparse: only sub-section aligned range would be populated David Hildenbrand
2020-07-01 2:32 ` Wei Yang
2020-07-01 9:27 ` David Hildenbrand
2020-06-30 18:11 ` kernel test robot
2020-07-01 11:58 ` Wei Yang
[not found] ` <MN2PR11MB4064B0104312A3D22F1698F3E5670@MN2PR11MB4064.namprd11.prod.outlook.com>
2020-07-08 18:20 ` Nick Desaulniers
2020-07-09 0:20 ` Philip Li
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