Currently, subsection map is used when SPARSEMEM is enabled, including
VMEMMAP case and !VMEMMAP case. However, subsection hotplug is not
supported at all in SPARSEMEM|!VMEMMAP case, subsection map is unnecessary
and misleading. Let's adjust code to only allow subsection map being
used in SPARSEMEM|VMEMMAP case.
Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
---
include/linux/mmzone.h | 2 +
mm/sparse.c | 231 ++++++++++++++++++++++-------------------
2 files changed, 124 insertions(+), 109 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 462f6873905a..fc0de3a9a51e 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1185,7 +1185,9 @@ static inline unsigned long section_nr_to_pfn(unsigned long sec)
#define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)
struct mem_section_usage {
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION);
+#endif
/* See declaration of similar field in struct zone */
unsigned long pageblock_flags[0];
};
diff --git a/mm/sparse.c b/mm/sparse.c
index 696f6b9f706e..cf55d272d0a9 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -209,41 +209,6 @@ static inline unsigned long first_present_section_nr(void)
return next_present_section_nr(-1);
}
-static void subsection_mask_set(unsigned long *map, unsigned long pfn,
- unsigned long nr_pages)
-{
- int idx = subsection_map_index(pfn);
- int end = subsection_map_index(pfn + nr_pages - 1);
-
- bitmap_set(map, idx, end - idx + 1);
-}
-
-void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
-{
- int end_sec = pfn_to_section_nr(pfn + nr_pages - 1);
- unsigned long nr, start_sec = pfn_to_section_nr(pfn);
-
- if (!nr_pages)
- return;
-
- for (nr = start_sec; nr <= end_sec; nr++) {
- struct mem_section *ms;
- unsigned long pfns;
-
- pfns = min(nr_pages, PAGES_PER_SECTION
- - (pfn & ~PAGE_SECTION_MASK));
- ms = __nr_to_section(nr);
- subsection_mask_set(ms->usage->subsection_map, pfn, pfns);
-
- pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr,
- pfns, subsection_map_index(pfn),
- subsection_map_index(pfn + pfns - 1));
-
- pfn += pfns;
- nr_pages -= pfns;
- }
-}
-
/* Record a memory area against a node. */
void __init memory_present(int nid, unsigned long start, unsigned long end)
{
@@ -432,12 +397,134 @@ static unsigned long __init section_map_size(void)
return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE);
}
+static void subsection_mask_set(unsigned long *map, unsigned long pfn,
+ unsigned long nr_pages)
+{
+ int idx = subsection_map_index(pfn);
+ int end = subsection_map_index(pfn + nr_pages - 1);
+
+ bitmap_set(map, idx, end - idx + 1);
+}
+
+void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
+{
+ int end_sec = pfn_to_section_nr(pfn + nr_pages - 1);
+ unsigned long nr, start_sec = pfn_to_section_nr(pfn);
+
+ if (!nr_pages)
+ return;
+
+ for (nr = start_sec; nr <= end_sec; nr++) {
+ struct mem_section *ms;
+ unsigned long pfns;
+
+ pfns = min(nr_pages, PAGES_PER_SECTION
+ - (pfn & ~PAGE_SECTION_MASK));
+ ms = __nr_to_section(nr);
+ subsection_mask_set(ms->usage->subsection_map, pfn, pfns);
+
+ pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr,
+ pfns, subsection_map_index(pfn),
+ subsection_map_index(pfn + pfns - 1));
+
+ pfn += pfns;
+ nr_pages -= pfns;
+ }
+}
+
+/**
+ * clear_subsection_map - Clear subsection map of one memory region
+ *
+ * @pfn - start pfn of the memory range
+ * @nr_pages - number of pfns to add in the region
+ *
+ * This is only intended for hotplug, and clear the related subsection
+ * map inside one section.
+ *
+ * Return:
+ * * -EINVAL - Section already deactived.
+ * * 0 - Subsection map is emptied.
+ * * 1 - Subsection map is not empty.
+ */
+static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
+{
+ DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
+ DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
+ struct mem_section *ms = __pfn_to_section(pfn);
+ unsigned long *subsection_map = ms->usage
+ ? &ms->usage->subsection_map[0] : NULL;
+
+ subsection_mask_set(map, pfn, nr_pages);
+ if (subsection_map)
+ bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION);
+
+ if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
+ "section already deactivated (%#lx + %ld)\n",
+ pfn, nr_pages))
+ return -EINVAL;
+
+ bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
+
+ if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION))
+ return 0;
+
+ return 1;
+}
+
+/**
+ * fill_subsection_map - fill subsection map of a memory region
+ * @pfn - start pfn of the memory range
+ * @nr_pages - number of pfns to add in the region
+ *
+ * This clears the related subsection map inside one section, and only
+ * intended for hotplug.
+ *
+ * Return:
+ * * 0 - On success.
+ * * -EINVAL - Invalid memory region.
+ * * -EEXIST - Subsection map has been set.
+ */
+static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
+{
+ struct mem_section *ms = __pfn_to_section(pfn);
+ DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
+ unsigned long *subsection_map;
+ int rc = 0;
+
+ subsection_mask_set(map, pfn, nr_pages);
+
+ subsection_map = &ms->usage->subsection_map[0];
+
+ if (bitmap_empty(map, SUBSECTIONS_PER_SECTION))
+ rc = -EINVAL;
+ else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION))
+ rc = -EEXIST;
+ else
+ bitmap_or(subsection_map, map, subsection_map,
+ SUBSECTIONS_PER_SECTION);
+
+ return rc;
+}
+
#else
static unsigned long __init section_map_size(void)
{
return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
}
+void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
+{
+}
+
+static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
+{
+ return 0;
+}
+static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
+{
+ return 0;
+}
+
struct page __init *__populate_section_memmap(unsigned long pfn,
unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
{
@@ -726,45 +813,6 @@ static void free_map_bootmem(struct page *memmap)
}
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
-/**
- * clear_subsection_map - Clear subsection map of one memory region
- *
- * @pfn - start pfn of the memory range
- * @nr_pages - number of pfns to add in the region
- *
- * This is only intended for hotplug, and clear the related subsection
- * map inside one section.
- *
- * Return:
- * * -EINVAL - Section already deactived.
- * * 0 - Subsection map is emptied.
- * * 1 - Subsection map is not empty.
- */
-static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
-{
- DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
- DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
- struct mem_section *ms = __pfn_to_section(pfn);
- unsigned long *subsection_map = ms->usage
- ? &ms->usage->subsection_map[0] : NULL;
-
- subsection_mask_set(map, pfn, nr_pages);
- if (subsection_map)
- bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION);
-
- if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
- "section already deactivated (%#lx + %ld)\n",
- pfn, nr_pages))
- return -EINVAL;
-
- bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
-
- if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION))
- return 0;
-
- return 1;
-}
-
static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
struct vmem_altmap *altmap)
{
@@ -818,41 +866,6 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
depopulate_section_memmap(pfn, nr_pages, altmap);
}
-/**
- * fill_subsection_map - fill subsection map of a memory region
- * @pfn - start pfn of the memory range
- * @nr_pages - number of pfns to add in the region
- *
- * This clears the related subsection map inside one section, and only
- * intended for hotplug.
- *
- * Return:
- * * 0 - On success.
- * * -EINVAL - Invalid memory region.
- * * -EEXIST - Subsection map has been set.
- */
-static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
-{
- struct mem_section *ms = __pfn_to_section(pfn);
- DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
- unsigned long *subsection_map;
- int rc = 0;
-
- subsection_mask_set(map, pfn, nr_pages);
-
- subsection_map = &ms->usage->subsection_map[0];
-
- if (bitmap_empty(map, SUBSECTIONS_PER_SECTION))
- rc = -EINVAL;
- else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION))
- rc = -EEXIST;
- else
- bitmap_or(subsection_map, map, subsection_map,
- SUBSECTIONS_PER_SECTION);
-
- return rc;
-}
-
static struct page * __meminit section_activate(int nid, unsigned long pfn,
unsigned long nr_pages, struct vmem_altmap *altmap)
{
--
2.17.2
