Revert "mm: Check if section present during memory block (un)registering"

This reverts commit 7568fb63f57ac8672f8bf2018171255441238882 as it's
already in Linus's tree through a different patch.

Reported-by: Tony Luck <tony.luck@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: stable@vger.kernel.org #v3.15
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 27 deletions

diff --git a/drivers/base/node.c b/drivers/base/node.c
index ae98ebaf6313..560751bad294 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -390,18 +390,7 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
         sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
         sect_end_pfn += PAGES_PER_SECTION - 1;
         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
-                int page_nid, scn_nr;
-
-                /*
-                 * memory block could have several absent sections from start.
-                 * skip pfn range from absent section
-                 */
-                scn_nr = pfn_to_section_nr(pfn);
-                if (!present_section_nr(scn_nr)) {
-                        pfn = round_down(pfn + PAGES_PER_SECTION,
-                                         PAGES_PER_SECTION) - 1;
-                        continue;
-                }
+                int page_nid;
 
                 /*
                  * memory block could have several absent sections from start.
@@ -447,22 +436,10 @@ int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
                 return -ENOMEM;
         nodes_clear(*unlinked_nodes);
 
-        sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
-        sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
-        sect_end_pfn += PAGES_PER_SECTION - 1;
+        sect_start_pfn = section_nr_to_pfn(phys_index);
+        sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
-                int nid, scn_nr;
-
-                /*
-                 * memory block could have several absent sections from start.
-                 * skip pfn range from absent section
-                 */
-                scn_nr = pfn_to_section_nr(pfn);
-                if (!present_section_nr(scn_nr)) {
-                        pfn = round_down(pfn + PAGES_PER_SECTION,
-                                         PAGES_PER_SECTION) - 1;
-                        continue;
-                }
+                int nid;
 
                 nid = get_nid_for_pfn(pfn);
                 if (nid < 0)