[3.16.y-ckt stable] Patch "Revert "mm: Check if section present during memory block (un)registering"" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

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

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt21.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 497e04078b7394820b093e4ee540472685d40da6 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Date: Tue, 13 Oct 2015 10:57:25 -0700
Subject: Revert "mm: Check if section present during memory block
 (un)registering"

commit 8346aa765e14348b7b436825b3c4740895a2fe1a upstream.

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

Reported-by: Tony Luck <tony.luck at intel.com>
Cc: Yinghai Lu <yinghai at kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/base/node.c | 31 ++++---------------------------
 1 file changed, 4 insertions(+), 27 deletions(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 7334e47996bc..5777d10d1e25 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -397,18 +397,7 @@ 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.
@@ -454,22 +443,10 @@ 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)