Re: memory-hotplug : suppres "Trying to free nonexistent resource <XXXXXXXXXXXXXXXX-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 as called in each PAGES_PER_SECTION
chunk since applying a patch(de7f0cba96786c). 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.

CC: David Rientjes <rientjes@google.com>
CC: Jiang Liu <redacted>
CC: Len Brown <redacted>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <redacted>
CC: Christoph Lameter <redacted>
Cc: Minchan Kim <redacted>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: KOSAKI Motohiro <redacted>
CC: Wen Congyang <redacted>
Signed-off-by: Yasuaki Ishimatsu <redacted>
---
 arch/powerpc/platforms/pseries/hotplug-memory.c |   13 +++++++++----
 mm/memory_hotplug.c                             |    4 ++--
 2 files changed, 11 insertions(+), 6 deletions(-)

Index: linux-3.6/arch/powerpc/platforms/pseries/hotplug-memory.c
===================================================================

--- linux-3.6.orig/arch/powerpc/platforms/pseries/hotplug-memory.c      2012-10-04 14:22:59.833520792 +0900
+++ linux-3.6/arch/powerpc/platforms/pseries/hotplug-memory.c   2012-10-04 14:23:05.150521411 +0900

@@ -77,7 +77,8 @@ static int pseries_remove_memblock(unsig
 {
        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(unsig
         * 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

Index: linux-3.6/mm/memory_hotplug.c
===================================================================

--- linux-3.6.orig/mm/memory_hotplug.c  2012-10-04 14:22:59.829520788 +0900
+++ linux-3.6/mm/memory_hotplug.c       2012-10-04 14:23:25.860527278 +0900

@@ -362,11 +362,11 @@ int __remove_pages(struct zone *zone, un
        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;

--

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