[PATCH v2 0/2] Preparing memhotplug for allocating memmap from hot-added range

[PATCH v2 0/2] Preparing memhotplug for allocating memmap from hot-added range

[Oscar Salvador]

v1 -> v2: Added David's feedback and his Reviewed-by

Hi,

these patches were posted as part of patchset [1], but it was agreed that
patch#3 must be further discussed.
Whole discussion can be seen in the cover letter.

But the first two patches make sense by themselves, as the first one is a nice
code cleanup, and the second one sets up the interface that the feature implemented
in [1] will use.

We decided to go this way because there are other people working on the same area,
and conflicts can arise easily, so better merge it now.
Also, it is safe as they do not implement any functional changes.

[1] https://patchwork.kernel.org/cover/10875017/

Michal Hocko (2):
  mm, memory_hotplug: cleanup memory offline path
  mm, memory_hotplug: provide a more generic restrictions for memory
    hotplug

 arch/arm64/mm/mmu.c            |  6 ++---
 arch/ia64/mm/init.c            |  6 ++---
 arch/powerpc/mm/mem.c          |  6 ++---
 arch/s390/mm/init.c            |  6 ++---
 arch/sh/mm/init.c              |  6 ++---
 arch/x86/mm/init_32.c          |  6 ++---
 arch/x86/mm/init_64.c          | 10 ++++----
 include/linux/memory_hotplug.h | 32 ++++++++++++++++++------
 kernel/memremap.c              | 12 ++++++---
 mm/memory_hotplug.c            | 56 ++++++++++++++----------------------------
 mm/page_alloc.c                | 11 +++++++--
 11 files changed, 84 insertions(+), 73 deletions(-)

-- 
2.13.7

[PATCH v2 1/2] mm, memory_hotplug: cleanup memory offline path

[Oscar Salvador]

From: Michal Hocko <mhocko@suse.com>

check_pages_isolated_cb currently accounts the whole pfn range as being
offlined if test_pages_isolated suceeds on the range. This is based on
the assumption that all pages in the range are freed which is currently
the case in most cases but it won't be with later changes, as pages
marked as vmemmap won't be isolated.

Move the offlined pages counting to offline_isolated_pages_cb and
rely on __offline_isolated_pages to return the correct value.
check_pages_isolated_cb will still do it's primary job and check the pfn
range.

While we are at it remove check_pages_isolated and offline_isolated_pages
and use directly walk_system_ram_range as do in online_pages.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
---
 include/linux/memory_hotplug.h |  3 ++-
 mm/memory_hotplug.c            | 45 +++++++++++-------------------------------
 mm/page_alloc.c                | 11 +++++++++--
 3 files changed, 22 insertions(+), 37 deletions(-)

diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 8ade08c50d26..3c8cf347804c 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -87,7 +87,8 @@ extern int add_one_highpage(struct page *page, int pfn, int bad_ppro);
 extern int online_pages(unsigned long, unsigned long, int);
 extern int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
 	unsigned long *valid_start, unsigned long *valid_end);
-extern void __offline_isolated_pages(unsigned long, unsigned long);
+extern unsigned long __offline_isolated_pages(unsigned long start_pfn,
+						unsigned long end_pfn);
 
 typedef void (*online_page_callback_t)(struct page *page, unsigned int order);
 
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index f206b8b66af1..d167737f888e 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1451,15 +1451,10 @@ static int
 offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
 			void *data)
 {
-	__offline_isolated_pages(start, start + nr_pages);
-	return 0;
-}
+	unsigned long *offlined_pages = (unsigned long *)data;
 
-static void
-offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
-{
-	walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL,
-				offline_isolated_pages_cb);
+	*offlined_pages += __offline_isolated_pages(start, start + nr_pages);
+	return 0;
 }
 
 /*
@@ -1469,26 +1464,7 @@ static int
 check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
 			void *data)
 {
-	int ret;
-	long offlined = *(long *)data;
-	ret = test_pages_isolated(start_pfn, start_pfn + nr_pages, true);
-	offlined = nr_pages;
-	if (!ret)
-		*(long *)data += offlined;
-	return ret;
-}
-
-static long
-check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
-{
-	long offlined = 0;
-	int ret;
-
-	ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined,
-			check_pages_isolated_cb);
-	if (ret < 0)
-		offlined = (long)ret;
-	return offlined;
+	return test_pages_isolated(start_pfn, start_pfn + nr_pages, true);
 }
 
 static int __init cmdline_parse_movable_node(char *p)
@@ -1573,7 +1549,7 @@ static int __ref __offline_pages(unsigned long start_pfn,
 		  unsigned long end_pfn)
 {
 	unsigned long pfn, nr_pages;
-	long offlined_pages;
+	unsigned long offlined_pages = 0;
 	int ret, node, nr_isolate_pageblock;
 	unsigned long flags;
 	unsigned long valid_start, valid_end;
@@ -1649,14 +1625,15 @@ static int __ref __offline_pages(unsigned long start_pfn,
 			goto failed_removal_isolated;
 		}
 		/* check again */
-		offlined_pages = check_pages_isolated(start_pfn, end_pfn);
-	} while (offlined_pages < 0);
+		ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn,
+					    NULL, check_pages_isolated_cb);
+	} while (ret);
 
-	pr_info("Offlined Pages %ld\n", offlined_pages);
 	/* Ok, all of our target is isolated.
 	   We cannot do rollback at this point. */
-	offline_isolated_pages(start_pfn, end_pfn);
-
+	walk_system_ram_range(start_pfn, end_pfn - start_pfn,
+			      &offlined_pages, offline_isolated_pages_cb);
+	pr_info("Offlined Pages %ld\n", offlined_pages);
 	/*
 	 * Onlining will reset pagetype flags and makes migrate type
 	 * MOVABLE, so just need to decrease the number of isolated
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0c53807a2943..d36ca67064c9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8375,7 +8375,7 @@ void zone_pcp_reset(struct zone *zone)
  * All pages in the range must be in a single zone and isolated
  * before calling this.
  */
-void
+unsigned long
 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
 {
 	struct page *page;
@@ -8383,12 +8383,15 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
 	unsigned int order, i;
 	unsigned long pfn;
 	unsigned long flags;
+	unsigned long offlined_pages = 0;
+
 	/* find the first valid pfn */
 	for (pfn = start_pfn; pfn < end_pfn; pfn++)
 		if (pfn_valid(pfn))
 			break;
 	if (pfn == end_pfn)
-		return;
+		return offlined_pages;
+
 	offline_mem_sections(pfn, end_pfn);
 	zone = page_zone(pfn_to_page(pfn));
 	spin_lock_irqsave(&zone->lock, flags);
@@ -8406,12 +8409,14 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
 		if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
 			pfn++;
 			SetPageReserved(page);
+			offlined_pages++;
 			continue;
 		}
 
 		BUG_ON(page_count(page));
 		BUG_ON(!PageBuddy(page));
 		order = page_order(page);
+		offlined_pages += 1 << order;
 #ifdef CONFIG_DEBUG_VM
 		pr_info("remove from free list %lx %d %lx\n",
 			pfn, 1 << order, end_pfn);
@@ -8422,6 +8427,8 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
 		pfn += (1 << order);
 	}
 	spin_unlock_irqrestore(&zone->lock, flags);
+
+	return offlined_pages;
 }
 #endif
 
-- 
2.13.7

[PATCH v2 2/2] mm, memory_hotplug: provide a more generic restrictions for memory hotplug

[Oscar Salvador]

From: Michal Hocko <mhocko@suse.com>

arch_add_memory, __add_pages take a want_memblock which controls whether
the newly added memory should get the sysfs memblock user API (e.g.
ZONE_DEVICE users do not want/need this interface). Some callers even
want to control where do we allocate the memmap from by configuring
altmap.

Add a more generic hotplug context for arch_add_memory and __add_pages.
struct mhp_restrictions contains flags which contains additional
features to be enabled by the memory hotplug (MHP_MEMBLOCK_API
currently) and altmap for alternative memmap allocator.

This patch shouldn't introduce any functional change.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
 arch/arm64/mm/mmu.c            |  6 +++---
 arch/ia64/mm/init.c            |  6 +++---
 arch/powerpc/mm/mem.c          |  6 +++---
 arch/s390/mm/init.c            |  6 +++---
 arch/sh/mm/init.c              |  6 +++---
 arch/x86/mm/init_32.c          |  6 +++---
 arch/x86/mm/init_64.c          | 10 +++++-----
 include/linux/memory_hotplug.h | 29 +++++++++++++++++++++++------
 kernel/memremap.c              | 12 +++++++++---
 mm/memory_hotplug.c            | 11 +++++++----
 10 files changed, 62 insertions(+), 36 deletions(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index e6acfa7be4c7..aa81713a01da 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1046,8 +1046,8 @@ int p4d_free_pud_page(p4d_t *p4d, unsigned long addr)
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
-		    bool want_memblock)
+int arch_add_memory(int nid, u64 start, u64 size,
+			struct mhp_restrictions *restrictions)
 {
 	int flags = 0;
 
@@ -1058,6 +1058,6 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
 			     size, PAGE_KERNEL, pgd_pgtable_alloc, flags);
 
 	return __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT,
-			   altmap, want_memblock);
+			   restrictions);
 }
 #endif
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index e49200e31750..379eb1f9adc9 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -666,14 +666,14 @@ mem_init (void)
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
-		bool want_memblock)
+int arch_add_memory(int nid, u64 start, u64 size,
+			struct mhp_restrictions *restrictions)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
 	int ret;
 
-	ret = __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
+	ret = __add_pages(nid, start_pfn, nr_pages, restrictions);
 	if (ret)
 		printk("%s: Problem encountered in __add_pages() as ret=%d\n",
 		       __func__,  ret);
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 1aa27aac73c5..76deaa8525db 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -109,8 +109,8 @@ int __weak remove_section_mapping(unsigned long start, unsigned long end)
 	return -ENODEV;
 }
 
-int __meminit arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
-		bool want_memblock)
+int __meminit arch_add_memory(int nid, u64 start, u64 size,
+			struct mhp_restrictions *restrictions)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
@@ -127,7 +127,7 @@ int __meminit arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *
 	}
 	flush_inval_dcache_range(start, start + size);
 
-	return __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
+	return __add_pages(nid, start_pfn, nr_pages, restrictions);
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 25e3113091ea..f5db961ad792 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -216,8 +216,8 @@ device_initcall(s390_cma_mem_init);
 
 #endif /* CONFIG_CMA */
 
-int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
-		bool want_memblock)
+int arch_add_memory(int nid, u64 start, u64 size,
+		struct mhp_restrictions *restrictions)
 {
 	unsigned long start_pfn = PFN_DOWN(start);
 	unsigned long size_pages = PFN_DOWN(size);
@@ -227,7 +227,7 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
 	if (rc)
 		return rc;
 
-	rc = __add_pages(nid, start_pfn, size_pages, altmap, want_memblock);
+	rc = __add_pages(nid, start_pfn, size_pages, restrictions);
 	if (rc)
 		vmem_remove_mapping(start, size);
 	return rc;
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 8e004b2f1a6a..168d3a6b9358 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -404,15 +404,15 @@ void __init mem_init(void)
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
-		bool want_memblock)
+int arch_add_memory(int nid, u64 start, u64 size,
+			struct mhp_restrictions *restrictions)
 {
 	unsigned long start_pfn = PFN_DOWN(start);
 	unsigned long nr_pages = size >> PAGE_SHIFT;
 	int ret;
 
 	/* We only have ZONE_NORMAL, so this is easy.. */
-	ret = __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
+	ret = __add_pages(nid, start_pfn, nr_pages, restrictions);
 	if (unlikely(ret))
 		printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
 
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 85c94f9a87f8..755dbed85531 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -850,13 +850,13 @@ void __init mem_init(void)
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
-		bool want_memblock)
+int arch_add_memory(int nid, u64 start, u64 size,
+			struct mhp_restrictions *restrictions)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
 
-	return __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
+	return __add_pages(nid, start_pfn, nr_pages, restrictions);
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index bccff68e3267..db42c11b48fb 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -777,11 +777,11 @@ static void update_end_of_memory_vars(u64 start, u64 size)
 }
 
 int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
-		struct vmem_altmap *altmap, bool want_memblock)
+				struct mhp_restrictions *restrictions)
 {
 	int ret;
 
-	ret = __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
+	ret = __add_pages(nid, start_pfn, nr_pages, restrictions);
 	WARN_ON_ONCE(ret);
 
 	/* update max_pfn, max_low_pfn and high_memory */
@@ -791,15 +791,15 @@ int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
 	return ret;
 }
 
-int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
-		bool want_memblock)
+int arch_add_memory(int nid, u64 start, u64 size,
+			struct mhp_restrictions *restrictions)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
 
 	init_memory_mapping(start, start + size);
 
-	return add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
+	return add_pages(nid, start_pfn, nr_pages, restrictions);
 }
 
 #define PAGE_INUSE 0xFD
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 3c8cf347804c..d0a145ffa4fe 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -118,20 +118,37 @@ extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
 	unsigned long nr_pages, struct vmem_altmap *altmap);
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
+/*
+ * Do we want sysfs memblock files created. This will allow userspace to online
+ * and offline memory explicitly. Lack of this bit means that the caller has to
+ * call move_pfn_range_to_zone to finish the initialization.
+ */
+
+#define MHP_MEMBLOCK_API               (1<<0)
+
+/*
+ * Restrictions for the memory hotplug:
+ * flags:  MHP_ flags
+ * altmap: alternative allocator for memmap array
+ */
+struct mhp_restrictions {
+	unsigned long flags;
+	struct vmem_altmap *altmap;
+};
+
 /* reasonably generic interface to expand the physical pages */
 extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
-		struct vmem_altmap *altmap, bool want_memblock);
+		       struct mhp_restrictions *restrictions);
 
 #ifndef CONFIG_ARCH_HAS_ADD_PAGES
 static inline int add_pages(int nid, unsigned long start_pfn,
-		unsigned long nr_pages, struct vmem_altmap *altmap,
-		bool want_memblock)
+		unsigned long nr_pages, struct mhp_restrictions *restrictions)
 {
-	return __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
+	return __add_pages(nid, start_pfn, nr_pages, restrictions);
 }
 #else /* ARCH_HAS_ADD_PAGES */
 int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
-		struct vmem_altmap *altmap, bool want_memblock);
+	      struct mhp_restrictions *restrictions);
 #endif /* ARCH_HAS_ADD_PAGES */
 
 #ifdef CONFIG_NUMA
@@ -333,7 +350,7 @@ extern int __add_memory(int nid, u64 start, u64 size);
 extern int add_memory(int nid, u64 start, u64 size);
 extern int add_memory_resource(int nid, struct resource *resource);
 extern int arch_add_memory(int nid, u64 start, u64 size,
-		struct vmem_altmap *altmap, bool want_memblock);
+			struct mhp_restrictions *restrictions);
 extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
 		unsigned long nr_pages, struct vmem_altmap *altmap);
 extern bool is_memblock_offlined(struct memory_block *mem);
diff --git a/kernel/memremap.c b/kernel/memremap.c
index a856cb5ff192..4e59d29245f4 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -148,6 +148,12 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
 			&pgmap->altmap : NULL;
 	struct resource *res = &pgmap->res;
 	struct dev_pagemap *conflict_pgmap;
+	struct mhp_restrictions restrictions = {
+		/*
+		 * We do not want any optional features only our own memmap
+		*/
+		.altmap = altmap,
+	};
 	pgprot_t pgprot = PAGE_KERNEL;
 	int error, nid, is_ram;
 
@@ -214,7 +220,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
 	 */
 	if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
 		error = add_pages(nid, align_start >> PAGE_SHIFT,
-				align_size >> PAGE_SHIFT, NULL, false);
+				align_size >> PAGE_SHIFT, &restrictions);
 	} else {
 		error = kasan_add_zero_shadow(__va(align_start), align_size);
 		if (error) {
@@ -222,8 +228,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
 			goto err_kasan;
 		}
 
-		error = arch_add_memory(nid, align_start, align_size, altmap,
-				false);
+		error = arch_add_memory(nid, align_start, align_size,
+					&restrictions);
 	}
 
 	if (!error) {
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index d167737f888e..4970ff658055 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -274,12 +274,12 @@ static int __meminit __add_section(int nid, unsigned long phys_start_pfn,
  * add the new pages.
  */
 int __ref __add_pages(int nid, unsigned long phys_start_pfn,
-		unsigned long nr_pages, struct vmem_altmap *altmap,
-		bool want_memblock)
+		unsigned long nr_pages, struct mhp_restrictions *restrictions)
 {
 	unsigned long i;
 	int err = 0;
 	int start_sec, end_sec;
+	struct vmem_altmap *altmap = restrictions->altmap;
 
 	/* during initialize mem_map, align hot-added range to section */
 	start_sec = pfn_to_section_nr(phys_start_pfn);
@@ -300,7 +300,7 @@ int __ref __add_pages(int nid, unsigned long phys_start_pfn,
 
 	for (i = start_sec; i <= end_sec; i++) {
 		err = __add_section(nid, section_nr_to_pfn(i), altmap,
-				want_memblock);
+				restrictions->flags & MHP_MEMBLOCK_API);
 
 		/*
 		 * EEXIST is finally dealt with by ioresource collision
@@ -1099,6 +1099,9 @@ static int online_memory_block(struct memory_block *mem, void *arg)
  */
 int __ref add_memory_resource(int nid, struct resource *res)
 {
+	struct mhp_restrictions restrictions = {
+		.flags = MHP_MEMBLOCK_API,
+	};
 	u64 start, size;
 	bool new_node = false;
 	int ret;
@@ -1126,7 +1129,7 @@ int __ref add_memory_resource(int nid, struct resource *res)
 	new_node = ret;
 
 	/* call arch's memory hotadd */
-	ret = arch_add_memory(nid, start, size, NULL, true);
+	ret = arch_add_memory(nid, start, size, &restrictions);
 	if (ret < 0)
 		goto error;
 
-- 
2.13.7

Re: [PATCH v2 2/2] mm, memory_hotplug: provide a more generic restrictions for memory hotplug

[Andrew Morton]

On Mon,  8 Apr 2019 10:26:33 +0200 Oscar Salvador <osalvador@suse.de> wrote:

> arch_add_memory, __add_pages take a want_memblock which controls whether
> the newly added memory should get the sysfs memblock user API (e.g.
> ZONE_DEVICE users do not want/need this interface). Some callers even
> want to control where do we allocate the memmap from by configuring
> altmap.
> 
> Add a more generic hotplug context for arch_add_memory and __add_pages.
> struct mhp_restrictions contains flags which contains additional
> features to be enabled by the memory hotplug (MHP_MEMBLOCK_API
> currently) and altmap for alternative memmap allocator.
> 
> This patch shouldn't introduce any functional change.

From: Andrew Morton <akpm@linux-foundation.org>
Subject: mm-memory_hotplug-provide-a-more-generic-restrictions-for-memory-hotplug-fix

x86_64 allnoconfig:

In file included from ./include/linux/mmzone.h:744:0,
                 from ./include/linux/gfp.h:6,
                 from ./include/linux/umh.h:4,
                 from ./include/linux/kmod.h:22,
                 from ./include/linux/module.h:13,
                 from init/do_mounts.c:1:
./include/linux/memory_hotplug.h:353:11: warning: ‘struct mhp_restrictions’ declared inside parameter list will not be visible outside of this definition or declaration
    struct mhp_restrictions *restrictions);
           ^~~~~~~~~~~~~~~~

Fix this by moving the arch_add_memory() definition inside
CONFIG_MEMORY_HOTPLUG and moving the mhp_restrictions definition to a more
appropriate place.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/memory_hotplug.h |   24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

--- a/include/linux/memory_hotplug.h~mm-memory_hotplug-provide-a-more-generic-restrictions-for-memory-hotplug-fix
+++ a/include/linux/memory_hotplug.h
@@ -54,6 +54,16 @@ enum {
 };
 
 /*
+ * Restrictions for the memory hotplug:
+ * flags:  MHP_ flags
+ * altmap: alternative allocator for memmap array
+ */
+struct mhp_restrictions {
+	unsigned long flags;
+	struct vmem_altmap *altmap;
+};
+
+/*
  * Zone resizing functions
  *
  * Note: any attempt to resize a zone should has pgdat_resize_lock()
@@ -101,6 +111,8 @@ extern void __online_page_free(struct pa
 
 extern int try_online_node(int nid);
 
+extern int arch_add_memory(int nid, u64 start, u64 size,
+			struct mhp_restrictions *restrictions);
 extern u64 max_mem_size;
 
 extern bool memhp_auto_online;
@@ -126,16 +138,6 @@ extern int __remove_pages(struct zone *z
 
 #define MHP_MEMBLOCK_API               (1<<0)
 
-/*
- * Restrictions for the memory hotplug:
- * flags:  MHP_ flags
- * altmap: alternative allocator for memmap array
- */
-struct mhp_restrictions {
-	unsigned long flags;
-	struct vmem_altmap *altmap;
-};
-
 /* reasonably generic interface to expand the physical pages */
 extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
 		       struct mhp_restrictions *restrictions);
@@ -349,8 +351,6 @@ extern int walk_memory_range(unsigned lo
 extern int __add_memory(int nid, u64 start, u64 size);
 extern int add_memory(int nid, u64 start, u64 size);
 extern int add_memory_resource(int nid, struct resource *resource);
-extern int arch_add_memory(int nid, u64 start, u64 size,
-			struct mhp_restrictions *restrictions);
 extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
 		unsigned long nr_pages, struct vmem_altmap *altmap);
 extern bool is_memblock_offlined(struct memory_block *mem);
_

Re: [PATCH v2 2/2] mm, memory_hotplug: provide a more generic restrictions for memory hotplug

[Michal Hocko]

On Mon 08-04-19 21:30:41, Andrew Morton wrote:
> On Mon,  8 Apr 2019 10:26:33 +0200 Oscar Salvador <osalvador@suse.de> wrote:
> 
> > arch_add_memory, __add_pages take a want_memblock which controls whether
> > the newly added memory should get the sysfs memblock user API (e.g.
> > ZONE_DEVICE users do not want/need this interface). Some callers even
> > want to control where do we allocate the memmap from by configuring
> > altmap.
> > 
> > Add a more generic hotplug context for arch_add_memory and __add_pages.
> > struct mhp_restrictions contains flags which contains additional
> > features to be enabled by the memory hotplug (MHP_MEMBLOCK_API
> > currently) and altmap for alternative memmap allocator.
> > 
> > This patch shouldn't introduce any functional change.
> 
> From: Andrew Morton <akpm@linux-foundation.org>
> Subject: mm-memory_hotplug-provide-a-more-generic-restrictions-for-memory-hotplug-fix
> 
> x86_64 allnoconfig:
> 
> In file included from ./include/linux/mmzone.h:744:0,
>                  from ./include/linux/gfp.h:6,
>                  from ./include/linux/umh.h:4,
>                  from ./include/linux/kmod.h:22,
>                  from ./include/linux/module.h:13,
>                  from init/do_mounts.c:1:
> ./include/linux/memory_hotplug.h:353:11: warning: ‘struct mhp_restrictions’ declared inside parameter list will not be visible outside of this definition or declaration
>     struct mhp_restrictions *restrictions);
>            ^~~~~~~~~~~~~~~~
> 
> Fix this by moving the arch_add_memory() definition inside
> CONFIG_MEMORY_HOTPLUG and moving the mhp_restrictions definition to a more
> appropriate place.

LGTM. Thanks for the fixup!

> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Oscar Salvador <osalvador@suse.de>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>  include/linux/memory_hotplug.h |   24 ++++++++++++------------
>  1 file changed, 12 insertions(+), 12 deletions(-)
> 
> --- a/include/linux/memory_hotplug.h~mm-memory_hotplug-provide-a-more-generic-restrictions-for-memory-hotplug-fix
> +++ a/include/linux/memory_hotplug.h
> @@ -54,6 +54,16 @@ enum {
>  };
>  
>  /*
> + * Restrictions for the memory hotplug:
> + * flags:  MHP_ flags
> + * altmap: alternative allocator for memmap array
> + */
> +struct mhp_restrictions {
> +	unsigned long flags;
> +	struct vmem_altmap *altmap;
> +};
> +
> +/*
>   * Zone resizing functions
>   *
>   * Note: any attempt to resize a zone should has pgdat_resize_lock()
> @@ -101,6 +111,8 @@ extern void __online_page_free(struct pa
>  
>  extern int try_online_node(int nid);
>  
> +extern int arch_add_memory(int nid, u64 start, u64 size,
> +			struct mhp_restrictions *restrictions);
>  extern u64 max_mem_size;
>  
>  extern bool memhp_auto_online;
> @@ -126,16 +138,6 @@ extern int __remove_pages(struct zone *z
>  
>  #define MHP_MEMBLOCK_API               (1<<0)
>  
> -/*
> - * Restrictions for the memory hotplug:
> - * flags:  MHP_ flags
> - * altmap: alternative allocator for memmap array
> - */
> -struct mhp_restrictions {
> -	unsigned long flags;
> -	struct vmem_altmap *altmap;
> -};
> -
>  /* reasonably generic interface to expand the physical pages */
>  extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
>  		       struct mhp_restrictions *restrictions);
> @@ -349,8 +351,6 @@ extern int walk_memory_range(unsigned lo
>  extern int __add_memory(int nid, u64 start, u64 size);
>  extern int add_memory(int nid, u64 start, u64 size);
>  extern int add_memory_resource(int nid, struct resource *resource);
> -extern int arch_add_memory(int nid, u64 start, u64 size,
> -			struct mhp_restrictions *restrictions);
>  extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
>  		unsigned long nr_pages, struct vmem_altmap *altmap);
>  extern bool is_memblock_offlined(struct memory_block *mem);
> _
> 

-- 
Michal Hocko
SUSE Labs