Allow sub-section sized ranges to be added to the memmap.
populate_section_memmap() takes an explict pfn range rather than
assuming a full section, and those parameters are plumbed all the way
through to vmmemap_populate(). There should be no sub-section usage in
current deployments. New warnings are added to clarify which memmap
allocation paths are sub-section capable.
Cc: Michal Hocko
Cc: David Hildenbrand
Cc: Logan Gunthorpe
Cc: Oscar Salvador
Reviewed-by: Pavel Tatashin
Signed-off-by: Dan Williams
---
arch/x86/mm/init_64.c |4 ++-
include/linux/mm.h|4 ++-
mm/sparse-vmemmap.c | 21 +++--
mm/sparse.c | 61 +++--
4 files changed, 57 insertions(+), 33 deletions(-)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 8335ac6e1112..688fb0687e55 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1520,7 +1520,9 @@ int __meminit vmemmap_populate(unsigned long start,
unsigned long end, int node,
{
int err;
- if (boot_cpu_has(X86_FEATURE_PSE))
+ if (end - start < PAGES_PER_SECTION * sizeof(struct page))
+ err = vmemmap_populate_basepages(start, end, node);
+ else if (boot_cpu_has(X86_FEATURE_PSE))
err = vmemmap_populate_hugepages(start, end, node, altmap);
else if (altmap) {
pr_err_once("%s: no cpu support for altmap allocations\n",
diff --git a/include/linux/mm.h b/include/linux/mm.h
index acc578407e9e..c502f3ce8661 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2734,8 +2734,8 @@ const char * arch_vma_name(struct vm_area_struct *vma);
void print_vma_addr(char *prefix, unsigned long rip);
void *sparse_buffer_alloc(unsigned long size);
-struct page *sparse_mem_map_populate(unsigned long pnum, int nid,
- struct vmem_altmap *altmap);
+struct page * __populate_section_memmap(unsigned long pfn,
+ unsigned long nr_pages, int nid, struct vmem_altmap *altmap);
pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
p4d_t *vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node);
pud_t *vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node);
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index 7fec05796796..200aef686722 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -245,19 +245,26 @@ int __meminit vmemmap_populate_basepages(unsigned long
start,
return 0;
}
-struct page * __meminit sparse_mem_map_populate(unsigned long pnum, int nid,
- struct vmem_altmap *altmap)
+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;
- struct page *map;
- map = pfn_to_page(pnum * PAGES_PER_SECTION);
- start = (unsigned long)map;
- end = (unsigned long)(map + PAGES_PER_SECTION);
+ /*
+* 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);
if (vmemmap_populate(start, end, nid, altmap))
return NULL;
- return map;
+ return pfn_to_page(pfn);
}
diff --git a/mm/sparse.c b/mm/sparse.c
index 0baa2e55cfdd..2093c662a5f7 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -439,8 +439,8 @@ static unsigned long __init section_map_size(void)
return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
}
-struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid,
- struct vmem_altmap *altmap)
+struct page __init *__populate_section_memmap(unsigned long pfn,
+ unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
{
unsigned long size = section_map_size();
struct page *map = sparse_buffer_alloc(size);
@@ -521,10 +521,13 @@ static void __init sparse_init_nid(int nid, unsigned long
pnum_begin,
}
sparse_buffer_init(map_count * section_map_size(), nid);
for_each_present_section_nr(pnum_begin, pnum) {
+ unsigned long pfn = section_nr_to_pfn(pnum);
+
if (pnum >= pnum_end)
break;
- map = sparse_mem_map_populate(pnum, nid, NULL);
+ map = __populate_section_memmap(pfn, PAGES_PER_SECTION,
+ nid, NULL);
if (!map) {
pr_err("%s: node[%d] memory map backing failed. Some
memory will not be available.",
__func__, nid);
@@ -624,17 +627,17 @@ void offline_mem_sections(unsigned long start_pfn,
unsigned
