On 03/13/20 at 09:42pm, Stephen Rothwell wrote:
> After merging the akpm-current tree, today's linux-next build (x86_64
> allnoconfig) produced this warning:
>
> mm/sparse.c:311:12: warning: 'fill_subsection_map' defined but not used [-Wunused-function]
> 311 | static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
> | ^~~~~~~~~~~~~~~~~~~
> mm/sparse.c:306:13: warning: 'is_subsection_map_empty' defined but not used [-Wunused-function]
> 306 | static bool is_subsection_map_empty(struct mem_section *ms)
> | ^~~~~~~~~~~~~~~~~~~~~~~
> mm/sparse.c:301:12: warning: 'clear_subsection_map' defined but not used [-Wunused-function]
> 301 | static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
> | ^~~~~~~~~~~~~~~~~~~~
Hi Stephen, Andrew,
I made a patch to fix these warnings, the reason has been told in the
log. Or just drop below patch. Both is fine to me.
mm-sparsec-move-subsection_map-related-functions-together.patch
>From 273196eeb7bbc4af93bef18f594af91541e3ce8a Mon Sep 17 00:00:00 2001
From: Baoquan He <bhe@xxxxxxxxxx>
Date: Sat, 14 Mar 2020 17:01:01 +0800
Subject: [PATCH] mm/sparse.c: move functions into CONFIG_MEMORY_HOTPLUG
ifdeffery scope
Stephen reported warnings are seen with allnoconfig on x86_64:
mm/sparse.c:311:12: warning: 'fill_subsection_map' defined but not used [-Wunused-function]
311 | static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
| ^~~~~~~~~~~~~~~~~~~
mm/sparse.c:306:13: warning: 'is_subsection_map_empty' defined but not used [-Wunused-function]
306 | static bool is_subsection_map_empty(struct mem_section *ms)
| ^~~~~~~~~~~~~~~~~~~~~~~
mm/sparse.c:301:12: warning: 'clear_subsection_map' defined but not used [-Wunused-function]
301 | static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
| ^~~~~~~~~~~~~~~~~~~~
This is because allnoconfig on x86_64 sets CONFIG_SPARSEMEM=y and
CONFIG_MEMORY_HOTPLUG=n. Functions clear_subsection_map(),
is_subsection_map_empty() and fill_subsection_map() are all defined
outside CONFIG_MEMORY_HOTPLUG ifdeffery scope. However, their callers,
section_activate() and section_deactivate() are inside CONFIG_MEMORY_HOTPLUG
ifdeffery scope.
So let's move them into the CONFIG_MEMORY_HOTPLUG iddeffery scope which
includes their callers.
Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
---
mm/sparse.c | 128 ++++++++++++++++++++++++++--------------------------
1 file changed, 64 insertions(+), 64 deletions(-)
diff --git a/mm/sparse.c b/mm/sparse.c
index bb99633575b5..9b845621b854 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -244,74 +244,10 @@ void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
nr_pages -= pfns;
}
}
-
-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);
- return 0;
-}
-
-static bool is_subsection_map_empty(struct mem_section *ms)
-{
- return bitmap_empty(&ms->usage->subsection_map[0],
- SUBSECTIONS_PER_SECTION);
-}
-
-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
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 bool is_subsection_map_empty(struct mem_section *ms)
-{
- return true;
-}
-
-static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
-{
- return 0;
-}
#endif
/* Record a memory area against a node. */
@@ -730,6 +666,55 @@ static void free_map_bootmem(struct page *memmap)
vmemmap_free(start, end, NULL);
}
+
+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);
+ return 0;
+}
+
+static bool is_subsection_map_empty(struct mem_section *ms)
+{
+ return bitmap_empty(&ms->usage->subsection_map[0],
+ SUBSECTIONS_PER_SECTION);
+}
+
+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
struct page * __meminit populate_section_memmap(unsigned long pfn,
unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
@@ -773,6 +758,21 @@ static void free_map_bootmem(struct page *memmap)
put_page_bootmem(page);
}
}
+
+static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
+{
+ return 0;
+}
+
+static bool is_subsection_map_empty(struct mem_section *ms)
+{
+ return true;
+}
+
+static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
+{
+ return 0;
+}
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
/*
--
2.17.2
