memory-hotplug: suppress "Trying to free nonexistent resource <XXXXXX…

…XXXXXXXXXX-YYYYYYYYYYYYYYYY>" warning

When our x86 box calls __remove_pages(), release_mem_region() shows many
warnings.  And x86 box cannot unregister iomem_resource.

  "Trying to free nonexistent resource <XXXXXXXXXXXXXXXX-YYYYYYYYYYYYYYYY>"

release_mem_region() has been changed to be called in each
PAGES_PER_SECTION by commit de7f0cb ("memory hotplug: release
memory regions in PAGES_PER_SECTION chunks").  Because powerpc registers
iomem_resource in each PAGES_PER_SECTION chunk.  But when I hot add
memory on x86 box, iomem_resource is register in each _CRS not
PAGES_PER_SECTION chunk.  So x86 box unregisters iomem_resource.

The patch fixes the problem.

Signed-off-by: Yasuaki Ishimatsu <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Jiang Liu <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Cc: Wen Congyang <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Nathan Fontenot <[email protected]>
Cc: Badari Pulavarty <[email protected]>
Cc: Yasunori Goto <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

arch/powerpc/platforms/pseries/hotplug-memory.c

@@ -77,7 +77,8 @@ static int pseries_remove_memblock(unsigned long base, unsigned int memblock_siz
 {
 	unsigned long start, start_pfn;
 	struct zone *zone;
-	int ret;
+	int i, ret;
+	int sections_to_remove;
 
 	start_pfn = base >> PAGE_SHIFT;
 
@@ -97,9 +98,13 @@ static int pseries_remove_memblock(unsigned long base, unsigned int memblock_siz
 	 * to sysfs "state" file and we can't remove sysfs entries
 	 * while writing to it. So we have to defer it to here.
 	 */
-	ret = __remove_pages(zone, start_pfn, memblock_size >> PAGE_SHIFT);
-	if (ret)
-		return ret;
+	sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION;
+	for (i = 0; i < sections_to_remove; i++) {
+		unsigned long pfn = start_pfn + i * PAGES_PER_SECTION;
+		ret = __remove_pages(zone, start_pfn,  PAGES_PER_SECTION);
+		if (ret)
+			return ret;
+	}
 
 	/*
 	 * Update memory regions for memory remove

mm/memory_hotplug.c

@@ -369,11 +369,11 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
 	BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
 	BUG_ON(nr_pages % PAGES_PER_SECTION);
 
+	release_mem_region(phys_start_pfn << PAGE_SHIFT, nr_pages * PAGE_SIZE);
+
 	sections_to_remove = nr_pages / PAGES_PER_SECTION;
 	for (i = 0; i < sections_to_remove; i++) {
 		unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
-		release_mem_region(pfn << PAGE_SHIFT,
-				   PAGES_PER_SECTION << PAGE_SHIFT);
 		ret = __remove_section(zone, __pfn_to_section(pfn));
 		if (ret)
 			break;