lkml.org 
[lkml]   [2020]   [Jun]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] mm/sparse: only sub-section aligned range would be populated
Date
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)
\
 
 \ /
  Last update: 2020-06-30 04:14    [W:0.077 / U:5.336 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site