memory-hotplug: suppress "Trying to free nonexistent resource <XXXXXXXXXXXXXXXX-YYYYY...
Yasuaki Ishimatsu [Mon, 8 Oct 2012 23:34:14 +0000 (16:34 -0700)]
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 de7f0cba9678 ("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 <isimatu.yasuaki@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Nathan Fontenot <nfont@austin.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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

index 11d8e05..dc0a035 100644 (file)
@@ -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
index 7d07974..56b758a 100644 (file)
@@ -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;