On 31.05.21 11:19, Dong Aisheng wrote:
The only path to call memory_present() is from memblocks_present().
The struct mem_section **mem_section only needs to be initialized once,
so no need put the initialization/allocation code in memory_present()
which will be called multiple times for each section.
After moving, the 'unlikely' condition statement becomes to be
meaningless as it's only initialized one time, so dropped as well.
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Signed-off-by: Dong Aisheng <aisheng.dong@xxxxxxx>
---
ChangeLog:
v1->v2:
* split into a helper function and called directly from sparse_init
---
mm/sparse.c | 29 ++++++++++++++++-------------
1 file changed, 16 insertions(+), 13 deletions(-)
diff --git a/mm/sparse.c b/mm/sparse.c
index 408b737e168e..d02ee6bb7cbc 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -60,6 +60,18 @@ static inline void set_section_nid(unsigned long section_nr, int nid)
#endif
#ifdef CONFIG_SPARSEMEM_EXTREME
+static void __init sparse_alloc_section_roots(void)
+{
+ unsigned long size, align;
+
+ size = sizeof(struct mem_section *) * NR_SECTION_ROOTS;
+ align = 1 << (INTERNODE_CACHE_SHIFT);
+ mem_section = memblock_alloc(size, align);
+ if (!mem_section)
+ panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+ __func__, size, align);
+}
+
static noinline struct mem_section __ref *sparse_index_alloc(int nid)
{
struct mem_section *section = NULL;
@@ -107,6 +119,8 @@ static inline int sparse_index_init(unsigned long section_nr, int nid)
{
return 0;
}
+
+static inline void sparse_alloc_section_roots(void) {}
#endif
#ifdef CONFIG_SPARSEMEM_EXTREME
@@ -254,19 +268,6 @@ static void __init memory_present(int nid, unsigned long start, unsigned long en
{
unsigned long pfn;
-#ifdef CONFIG_SPARSEMEM_EXTREME
- if (unlikely(!mem_section)) {
- unsigned long size, align;
-
- size = sizeof(struct mem_section *) * NR_SECTION_ROOTS;
- align = 1 << (INTERNODE_CACHE_SHIFT);
- mem_section = memblock_alloc(size, align);
- if (!mem_section)
- panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
- __func__, size, align);
- }
-#endif
-
start &= PAGE_SECTION_MASK;
mminit_validate_memmodel_limits(&start, &end);
for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
@@ -582,6 +583,8 @@ void __init sparse_init(void)
unsigned long pnum_end, pnum_begin, map_count = 1;
int nid_begin;
+ sparse_alloc_section_roots();
+
memblocks_present();
pnum_begin = first_present_section_nr();
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
--
Thanks,
David / dhildenb
