[v2,3/5] mm, memory_hotplug: Move zone/pages handling to offline stage
diff mbox series

Message ID 20181127162005.15833-4-osalvador@suse.de
State New
Headers show
Series
  • Do not touch pages in hot-remove path
Related show

Commit Message

Oscar Salvador Nov. 27, 2018, 4:20 p.m. UTC
From: Oscar Salvador <osalvador@suse.com>

The current implementation accesses pages during hot-remove
stage in order to get the zone linked to this memory-range.
We use that zone for a) check if the zone is ZONE_DEVICE and
b) to shrink the zone's spanned pages.

Accessing pages during this stage is problematic, as we might be
accessing pages that were not initialized if we did not get to
online the memory before removing it.

The only reason to check for ZONE_DEVICE in __remove_pages
is to bypass the call to release_mem_region_adjustable(),
since these regions are removed with devm_release_mem_region.

With patch#2, this is no longer a problem so we can safely
call release_mem_region_adjustable().
release_mem_region_adjustable() will spot that the region
we are trying to remove was acquired by means of
devm_request_mem_region, and will back off safely.

This allows us to remove all zone-related operations from
hot-remove stage.

Because of this, zone's spanned pages are shrinked during
the offlining stage in shrink_zone_pgdat().
It would have been great to decrease also the spanned page
for the node there, but we need them in try_offline_node().
So we still decrease spanned pages for the node in the hot-remove
stage.

The only particularity is that now
find_smallest_section_pfn/find_biggest_section_pfn, when called from
shrink_zone_span, will now check for online sections and not
valid sections instead.
To make this work with devm/HMM code, we need to call offline_mem_sections
and online_mem_sections in that code path when we are adding memory.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
 arch/powerpc/mm/mem.c          | 11 +----
 arch/sh/mm/init.c              |  4 +-
 arch/x86/mm/init_32.c          |  3 +-
 arch/x86/mm/init_64.c          |  8 +---
 include/linux/memory_hotplug.h |  8 ++--
 kernel/memremap.c              | 14 +++++--
 mm/memory_hotplug.c            | 95 ++++++++++++++++++++++++------------------
 mm/sparse.c                    |  4 +-
 8 files changed, 76 insertions(+), 71 deletions(-)

Comments

Mike Rapoport Nov. 28, 2018, 7:52 a.m. UTC | #1
On Tue, Nov 27, 2018 at 05:20:03PM +0100, Oscar Salvador wrote:
> From: Oscar Salvador <osalvador@suse.com>
> 
> The current implementation accesses pages during hot-remove
> stage in order to get the zone linked to this memory-range.
> We use that zone for a) check if the zone is ZONE_DEVICE and
> b) to shrink the zone's spanned pages.
> 
> Accessing pages during this stage is problematic, as we might be
> accessing pages that were not initialized if we did not get to
> online the memory before removing it.
> 
> The only reason to check for ZONE_DEVICE in __remove_pages
> is to bypass the call to release_mem_region_adjustable(),
> since these regions are removed with devm_release_mem_region.
> 
> With patch#2, this is no longer a problem so we can safely
> call release_mem_region_adjustable().
> release_mem_region_adjustable() will spot that the region
> we are trying to remove was acquired by means of
> devm_request_mem_region, and will back off safely.
> 
> This allows us to remove all zone-related operations from
> hot-remove stage.
> 
> Because of this, zone's spanned pages are shrinked during
> the offlining stage in shrink_zone_pgdat().
> It would have been great to decrease also the spanned page
> for the node there, but we need them in try_offline_node().
> So we still decrease spanned pages for the node in the hot-remove
> stage.
> 
> The only particularity is that now
> find_smallest_section_pfn/find_biggest_section_pfn, when called from
> shrink_zone_span, will now check for online sections and not
> valid sections instead.
> To make this work with devm/HMM code, we need to call offline_mem_sections
> and online_mem_sections in that code path when we are adding memory.
> 
> Signed-off-by: Oscar Salvador <osalvador@suse.de>
> ---
>  arch/powerpc/mm/mem.c          | 11 +----
>  arch/sh/mm/init.c              |  4 +-
>  arch/x86/mm/init_32.c          |  3 +-
>  arch/x86/mm/init_64.c          |  8 +---
>  include/linux/memory_hotplug.h |  8 ++--
>  kernel/memremap.c              | 14 +++++--
>  mm/memory_hotplug.c            | 95 ++++++++++++++++++++++++------------------
>  mm/sparse.c                    |  4 +-
>  8 files changed, 76 insertions(+), 71 deletions(-)
 
[ ... ]
 
>  /**
> - * __remove_pages() - remove sections of pages from a zone
> - * @zone: zone from which pages need to be removed
> + * __remove_pages() - remove sections of pages from a nid
> + * @nid: nid from which pages belong to

Nit: the description sounds a bit awkward.
Why not to keep the original one with s/zone/node/?

>   * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
>   * @nr_pages: number of pages to remove (must be multiple of section size)
>   * @altmap: alternative device page map or %NULL if default memmap is used
> @@ -547,35 +566,28 @@ static int __remove_section(struct zone *zone, struct mem_section *ms,
>   * sure that pages are marked reserved and zones are adjust properly by
>   * calling offline_pages().
>   */
Oscar Salvador Nov. 28, 2018, 2:15 p.m. UTC | #2
On 2018-11-27 17:20, Oscar Salvador wrote:
> From: Oscar Salvador <osalvador@suse.com>
> 
> The current implementation accesses pages during hot-remove
> stage in order to get the zone linked to this memory-range.
> We use that zone for a) check if the zone is ZONE_DEVICE and
> b) to shrink the zone's spanned pages.
> 
> Accessing pages during this stage is problematic, as we might be
> accessing pages that were not initialized if we did not get to
> online the memory before removing it.
> 
> The only reason to check for ZONE_DEVICE in __remove_pages
> is to bypass the call to release_mem_region_adjustable(),
> since these regions are removed with devm_release_mem_region.
> 
> With patch#2, this is no longer a problem so we can safely
> call release_mem_region_adjustable().
> release_mem_region_adjustable() will spot that the region
> we are trying to remove was acquired by means of
> devm_request_mem_region, and will back off safely.
> 
> This allows us to remove all zone-related operations from
> hot-remove stage.
> 
> Because of this, zone's spanned pages are shrinked during
> the offlining stage in shrink_zone_pgdat().
> It would have been great to decrease also the spanned page
> for the node there, but we need them in try_offline_node().
> So we still decrease spanned pages for the node in the hot-remove
> stage.
> 
> The only particularity is that now
> find_smallest_section_pfn/find_biggest_section_pfn, when called from
> shrink_zone_span, will now check for online sections and not
> valid sections instead.
> To make this work with devm/HMM code, we need to call 
> offline_mem_sections
> and online_mem_sections in that code path when we are adding memory.
> 
> Signed-off-by: Oscar Salvador <osalvador@suse.de>

I did not really like the idea of having to online/offline sections from 
DEVM code, so I think
this should be better:

diff --git a/kernel/memremap.c b/kernel/memremap.c
index 66cbf334203b..dfdb11f58cd1 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -105,7 +105,6 @@ static void devm_memremap_pages_release(void *data)

  	pfn = align_start >> PAGE_SHIFT;
  	nr_pages = align_size >> PAGE_SHIFT;
-	offline_mem_sections(pfn, pfn + nr_pages);
  	shrink_zone(page_zone(pfn_to_page(pfn)), pfn, pfn + nr_pages, 
nr_pages);

  	if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
@@ -229,10 +228,7 @@ void *devm_memremap_pages(struct device *dev, 
struct dev_pagemap *pgmap)

  	if (!error) {
  		struct zone *zone;
-		unsigned long pfn = align_start >> PAGE_SHIFT;
-		unsigned long nr_pages = align_size >> PAGE_SHIFT;

-		online_mem_sections(pfn, pfn + nr_pages);
  		zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
  		move_pfn_range_to_zone(zone, align_start >> PAGE_SHIFT,
  				align_size >> PAGE_SHIFT, altmap);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 4fe42ccb0be4..653d2bc9affe 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -314,13 +314,17 @@ int __ref __add_pages(int nid, unsigned long 
phys_start_pfn,
  }

  #ifdef CONFIG_MEMORY_HOTREMOVE
-static bool is_section_ok(struct mem_section *ms, bool zone)
+static bool is_section_ok(struct mem_section *ms, struct zone *z)
  {
  	/*
-	 * We cannot shrink pgdat's spanned because we use them
-	 * in try_offline_node to check if all sections were removed.
+	 * In case we are shrinking pgdat's pages or the zone is
+	 * ZONE_DEVICE, we check for valid sections instead.
+	 * We cannot shrink pgdat's spanned pages until hot-remove
+	 * operation because we use them in try_offline_node to check
+	 * if all sections were removed.
+	 * ZONE_DEVICE's sections do not get onlined either.
  	 */
-	if (zone)
+	if (z && !is_dev_zone(z))
  		return online_section(ms);
  	else
  		return valid_section(ms);
@@ -335,7 +339,7 @@ static unsigned long find_smallest_section_pfn(int 
nid, struct zone *zone,
  	for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) {
  		ms = __pfn_to_section(start_pfn);

-		if (!is_section_ok(ms, !!zone))
+		if (!is_section_ok(ms, zone))
  			continue;

  		if (unlikely(pfn_to_nid(start_pfn) != nid))
@@ -425,7 +429,7 @@ static void shrink_zone_span(struct zone *zone, 
unsigned long start_pfn,
  	for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) {
  		ms = __pfn_to_section(pfn);

-		if (unlikely(!online_section(ms)))
+		if (unlikely(!is_section_ok(ms, zone)))
  			continue;

  		if (page_zone(pfn_to_page(pfn)) != zone)
@@ -517,11 +521,24 @@ void shrink_zone(struct zone *zone, unsigned long 
start_pfn,
  {
  	int nr_pages = PAGES_PER_SECTION;
  	unsigned long pfn;
+	unsigned long flags;
+	struct pglist_data *pgdat = zone->zone_pgdat;
+
+	pgdat_resize_lock(pgdat, &flags);
+	/*
+	 * Handling for ZONE_DEVICE does not account
+	 * present pages.
+	 */
+	if (!is_dev_zone(zone))
+		pgdat->node_present_pages -= offlined_pages;
+

  	clear_zone_contiguous(zone);
  	for (pfn = start_pfn; pfn < end_pfn; pfn += nr_pages)
  		shrink_zone_span(zone, pfn, pfn + nr_pages);
  	set_zone_contiguous(zone);
+
+	pgdat_resize_unlock(pgdat, &flags);
  }

  static void shrink_pgdat(int nid, unsigned long sect_nr)
@@ -555,8 +572,8 @@ static int __remove_section(int nid, struct 
mem_section *ms,
  }

  /**
- * __remove_pages() - remove sections of pages from a nid
- * @nid: nid from which pages belong to
+ * remove_sections() - remove sections of pages from a nid
+ * @nid: node from which pages need to be removed to
   * @phys_start_pfn: starting pageframe (must be aligned to start of a 
section)
   * @nr_pages: number of pages to remove (must be multiple of section 
size)
   * @altmap: alternative device page map or %NULL if default memmap is 
used
@@ -1581,7 +1598,6 @@ static int __ref __offline_pages(unsigned long 
start_pfn,
  	unsigned long pfn, nr_pages;
  	long offlined_pages;
  	int ret, node;
-	unsigned long flags;
  	unsigned long valid_start, valid_end;
  	struct zone *zone;
  	struct memory_notify arg;
@@ -1663,14 +1679,12 @@ static int __ref __offline_pages(unsigned long 
start_pfn,
  	undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
  	/* removal success */

-	/* Shrink zone's managed,spanned and zone/pgdat's present pages */
+	/* Shrink zone's managed and present pages */
  	adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages);
  	zone->present_pages -= offlined_pages;

-	pgdat_resize_lock(zone->zone_pgdat, &flags);
-	zone->zone_pgdat->node_present_pages -= offlined_pages;
+	/* Shrink zone's spanned pages and node's present pages */
  	shrink_zone(zone, valid_start, valid_end, offlined_pages);
-	pgdat_resize_unlock(zone->zone_pgdat, &flags);

  	init_per_zone_wmark_min();

Although there is an ongoing discussion for getting rid of the shrink 
code.
If that is the case, this will be a lot simpler.
Oscar Salvador Nov. 28, 2018, 2:25 p.m. UTC | #3
>>  /**
>> - * __remove_pages() - remove sections of pages from a zone
>> - * @zone: zone from which pages need to be removed
>> + * __remove_pages() - remove sections of pages from a nid
>> + * @nid: nid from which pages belong to
> 
> Nit: the description sounds a bit awkward.
> Why not to keep the original one with s/zone/node/?

Yes, much better.

thanks

Patch
diff mbox series

diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 40feb262080e..b3c9ee5c4f78 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -144,18 +144,9 @@  int __meminit arch_remove_memory(int nid, u64 start, u64 size,
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
-	struct page *page;
 	int ret;
 
-	/*
-	 * If we have an altmap then we need to skip over any reserved PFNs
-	 * when querying the zone.
-	 */
-	page = pfn_to_page(start_pfn);
-	if (altmap)
-		page += vmem_altmap_offset(altmap);
-
-	ret = __remove_pages(page_zone(page), start_pfn, nr_pages, altmap);
+	ret = remove_sections(nid, start_pfn, nr_pages, altmap);
 	if (ret)
 		return ret;
 
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index a8e5c0e00fca..1a483a008872 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -447,11 +447,9 @@  int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)
 {
 	unsigned long start_pfn = PFN_DOWN(start);
 	unsigned long nr_pages = size >> PAGE_SHIFT;
-	struct zone *zone;
 	int ret;
 
-	zone = page_zone(pfn_to_page(start_pfn));
-	ret = __remove_pages(zone, start_pfn, nr_pages, altmap);
+	ret = remove_sections(nid, start_pfn, nr_pages, altmap);
 	if (unlikely(ret))
 		pr_warn("%s: Failed, __remove_pages() == %d\n", __func__,
 			ret);
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 85c94f9a87f8..0b8c7b0033d2 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -866,8 +866,7 @@  int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)
 	unsigned long nr_pages = size >> PAGE_SHIFT;
 	struct zone *zone;
 
-	zone = page_zone(pfn_to_page(start_pfn));
-	return __remove_pages(zone, start_pfn, nr_pages, altmap);
+	return remove_sections(nid, start_pfn, nr_pages, altmap);
 }
 #endif
 #endif
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 449958da97a4..f80d98381a97 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1152,15 +1152,9 @@  int __ref arch_remove_memory(int nid, u64 start, u64 size,
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
-	struct page *page = pfn_to_page(start_pfn);
-	struct zone *zone;
 	int ret;
 
-	/* With altmap the first mapped page is offset from @start */
-	if (altmap)
-		page += vmem_altmap_offset(altmap);
-	zone = page_zone(page);
-	ret = __remove_pages(zone, start_pfn, nr_pages, altmap);
+	ret = remove_sections(nid, start_pfn, nr_pages, altmap);
 	WARN_ON_ONCE(ret);
 	kernel_physical_mapping_remove(start, start + size);
 
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 3aedcd7929cd..0a882d8e32c6 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -109,8 +109,10 @@  static inline bool movable_node_is_enabled(void)
 #ifdef CONFIG_MEMORY_HOTREMOVE
 extern int arch_remove_memory(int nid, u64 start, u64 size,
 				struct vmem_altmap *altmap);
-extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
-	unsigned long nr_pages, struct vmem_altmap *altmap);
+extern int remove_sections(int nid, unsigned long start_pfn,
+			unsigned long nr_pages, struct vmem_altmap *altmap);
+extern void shrink_zone(struct zone *zone, unsigned long start_pfn,
+			unsigned long end_pfn, unsigned long offlined_pages);
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
 /* reasonably generic interface to expand the physical pages */
@@ -335,7 +337,7 @@  extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
 extern bool is_memblock_offlined(struct memory_block *mem);
 extern int sparse_add_one_section(struct pglist_data *pgdat,
 		unsigned long start_pfn, struct vmem_altmap *altmap);
-extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
+extern void sparse_remove_one_section(int nid, struct mem_section *ms,
 		unsigned long map_offset, struct vmem_altmap *altmap);
 extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
 					  unsigned long pnum);
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 0d5603d76c37..66cbf334203b 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -87,6 +87,7 @@  static void devm_memremap_pages_release(void *data)
 	struct resource *res = &pgmap->res;
 	resource_size_t align_start, align_size;
 	unsigned long pfn;
+	unsigned long nr_pages;
 	int nid;
 
 	pgmap->kill(pgmap->ref);
@@ -101,10 +102,14 @@  static void devm_memremap_pages_release(void *data)
 	nid = page_to_nid(pfn_to_page(align_start >> PAGE_SHIFT));
 
 	mem_hotplug_begin();
+
+	pfn = align_start >> PAGE_SHIFT;
+	nr_pages = align_size >> PAGE_SHIFT;
+	offline_mem_sections(pfn, pfn + nr_pages);
+	shrink_zone(page_zone(pfn_to_page(pfn)), pfn, pfn + nr_pages, nr_pages);
+
 	if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
-		pfn = align_start >> PAGE_SHIFT;
-		__remove_pages(page_zone(pfn_to_page(pfn)), pfn,
-				align_size >> PAGE_SHIFT, NULL);
+		remove_sections(nid, pfn, nr_pages, NULL);
 	} else {
 		arch_remove_memory(nid, align_start, align_size,
 				pgmap->altmap_valid ? &pgmap->altmap : NULL);
@@ -224,7 +229,10 @@  void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
 
 	if (!error) {
 		struct zone *zone;
+		unsigned long pfn = align_start >> PAGE_SHIFT;
+		unsigned long nr_pages = align_size >> PAGE_SHIFT;
 
+		online_mem_sections(pfn, pfn + nr_pages);
 		zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
 		move_pfn_range_to_zone(zone, align_start >> PAGE_SHIFT,
 				align_size >> PAGE_SHIFT, altmap);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 849bcc55c5f1..4fe42ccb0be4 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -314,6 +314,17 @@  int __ref __add_pages(int nid, unsigned long phys_start_pfn,
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
+static bool is_section_ok(struct mem_section *ms, bool zone)
+{
+	/*
+	 * We cannot shrink pgdat's spanned because we use them
+	 * in try_offline_node to check if all sections were removed.
+	 */
+	if (zone)
+		return online_section(ms);
+	else
+		return valid_section(ms);
+}
 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
 static unsigned long find_smallest_section_pfn(int nid, struct zone *zone,
 				     unsigned long start_pfn,
@@ -324,7 +335,7 @@  static unsigned long find_smallest_section_pfn(int nid, struct zone *zone,
 	for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) {
 		ms = __pfn_to_section(start_pfn);
 
-		if (unlikely(!valid_section(ms)))
+		if (!is_section_ok(ms, !!zone))
 			continue;
 
 		if (unlikely(pfn_to_nid(start_pfn) != nid))
@@ -352,7 +363,7 @@  static unsigned long find_biggest_section_pfn(int nid, struct zone *zone,
 	for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) {
 		ms = __pfn_to_section(pfn);
 
-		if (unlikely(!valid_section(ms)))
+		if (!is_section_ok(ms, !!zone))
 			continue;
 
 		if (unlikely(pfn_to_nid(pfn) != nid))
@@ -414,7 +425,7 @@  static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
 	for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) {
 		ms = __pfn_to_section(pfn);
 
-		if (unlikely(!valid_section(ms)))
+		if (unlikely(!online_section(ms)))
 			continue;
 
 		if (page_zone(pfn_to_page(pfn)) != zone)
@@ -501,23 +512,33 @@  static void shrink_pgdat_span(struct pglist_data *pgdat,
 	pgdat->node_spanned_pages = 0;
 }
 
-static void __remove_zone(struct zone *zone, unsigned long start_pfn)
+void shrink_zone(struct zone *zone, unsigned long start_pfn,
+		unsigned long end_pfn, unsigned long offlined_pages)
 {
-	struct pglist_data *pgdat = zone->zone_pgdat;
 	int nr_pages = PAGES_PER_SECTION;
+	unsigned long pfn;
+
+	clear_zone_contiguous(zone);
+	for (pfn = start_pfn; pfn < end_pfn; pfn += nr_pages)
+		shrink_zone_span(zone, pfn, pfn + nr_pages);
+	set_zone_contiguous(zone);
+}
+
+static void shrink_pgdat(int nid, unsigned long sect_nr)
+{
+	struct pglist_data *pgdat = NODE_DATA(nid);
+	int nr_pages = PAGES_PER_SECTION;
+	unsigned long pfn = section_nr_to_pfn((unsigned long)sect_nr);
 	unsigned long flags;
 
-	pgdat_resize_lock(zone->zone_pgdat, &flags);
-	shrink_zone_span(zone, start_pfn, start_pfn + nr_pages);
-	shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages);
-	pgdat_resize_unlock(zone->zone_pgdat, &flags);
+	pgdat_resize_lock(pgdat, &flags);
+	shrink_pgdat_span(pgdat, pfn, pfn + nr_pages);
+	pgdat_resize_unlock(pgdat, &flags);
 }
 
-static int __remove_section(struct zone *zone, struct mem_section *ms,
+static int __remove_section(int nid, struct mem_section *ms,
 		unsigned long map_offset, struct vmem_altmap *altmap)
 {
-	unsigned long start_pfn;
-	int scn_nr;
 	int ret = -EINVAL;
 
 	if (!valid_section(ms))
@@ -527,17 +548,15 @@  static int __remove_section(struct zone *zone, struct mem_section *ms,
 	if (ret)
 		return ret;
 
-	scn_nr = __section_nr(ms);
-	start_pfn = section_nr_to_pfn((unsigned long)scn_nr);
-	__remove_zone(zone, start_pfn);
+	shrink_pgdat(nid, __section_nr(ms));
 
-	sparse_remove_one_section(zone, ms, map_offset, altmap);
+	sparse_remove_one_section(nid, ms, map_offset, altmap);
 	return 0;
 }
 
 /**
- * __remove_pages() - remove sections of pages from a zone
- * @zone: zone from which pages need to be removed
+ * __remove_pages() - remove sections of pages from a nid
+ * @nid: nid from which pages belong to
  * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
  * @nr_pages: number of pages to remove (must be multiple of section size)
  * @altmap: alternative device page map or %NULL if default memmap is used
@@ -547,35 +566,28 @@  static int __remove_section(struct zone *zone, struct mem_section *ms,
  * sure that pages are marked reserved and zones are adjust properly by
  * calling offline_pages().
  */
-int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
+int remove_sections(int nid, unsigned long phys_start_pfn,
 		 unsigned long nr_pages, struct vmem_altmap *altmap)
 {
 	unsigned long i;
 	unsigned long map_offset = 0;
 	int sections_to_remove, ret = 0;
+	resource_size_t start, size;
 
-	/* In the ZONE_DEVICE case device driver owns the memory region */
-	if (is_dev_zone(zone)) {
-		if (altmap)
-			map_offset = vmem_altmap_offset(altmap);
-	} else {
-		resource_size_t start, size;
-
-		start = phys_start_pfn << PAGE_SHIFT;
-		size = nr_pages * PAGE_SIZE;
+	start = phys_start_pfn << PAGE_SHIFT;
+	size = nr_pages * PAGE_SIZE;
 
-		ret = release_mem_region_adjustable(&iomem_resource, start,
-					size);
-		if (ret) {
-			resource_size_t endres = start + size - 1;
+	if (altmap)
+		map_offset = vmem_altmap_offset(altmap);
 
-			pr_warn("Unable to release resource <%pa-%pa> (%d)\n",
-					&start, &endres, ret);
-		}
+	ret = release_mem_region_adjustable(&iomem_resource, start,
+								size);
+	if (ret) {
+		resource_size_t endres = start + size - 1;
+		pr_warn("Unable to release resource <%pa-%pa> (%d)\n",
+						&start, &endres, ret);
 	}
 
-	clear_zone_contiguous(zone);
-
 	/*
 	 * We can only remove entire sections
 	 */
@@ -587,15 +599,13 @@  int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
 		unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
 
 		cond_resched();
-		ret = __remove_section(zone, __pfn_to_section(pfn), map_offset,
-				altmap);
+		ret = __remove_section(nid, __pfn_to_section(pfn), map_offset,
+									altmap);
 		map_offset = 0;
 		if (ret)
 			break;
 	}
 
-	set_zone_contiguous(zone);
-
 	return ret;
 }
 #endif /* CONFIG_MEMORY_HOTREMOVE */
@@ -1652,11 +1662,14 @@  static int __ref __offline_pages(unsigned long start_pfn,
 	/* reset pagetype flags and makes migrate type to be MOVABLE */
 	undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
 	/* removal success */
+
+	/* Shrink zone's managed,spanned and zone/pgdat's present pages */
 	adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages);
 	zone->present_pages -= offlined_pages;
 
 	pgdat_resize_lock(zone->zone_pgdat, &flags);
 	zone->zone_pgdat->node_present_pages -= offlined_pages;
+	shrink_zone(zone, valid_start, valid_end, offlined_pages);
 	pgdat_resize_unlock(zone->zone_pgdat, &flags);
 
 	init_per_zone_wmark_min();
diff --git a/mm/sparse.c b/mm/sparse.c
index 691544a2814c..01aa42102f8b 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -790,12 +790,12 @@  static void free_section_usemap(struct page *memmap, unsigned long *usemap,
 		free_map_bootmem(memmap);
 }
 
-void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
+void sparse_remove_one_section(int nid, struct mem_section *ms,
 		unsigned long map_offset, struct vmem_altmap *altmap)
 {
 	struct page *memmap = NULL;
 	unsigned long *usemap = NULL, flags;
-	struct pglist_data *pgdat = zone->zone_pgdat;
+	struct pglist_data *pgdat = NODE_DATA(nid);
 
 	pgdat_resize_lock(pgdat, &flags);
 	if (ms->section_mem_map) {