[v3,1/5] mm,memory_hotplug: Introduce MHP_MEMMAP_ON_MEMORY
diff mbox series

Message ID 20190725160207.19579-2-osalvador@suse.de
State New
Headers show
Series
  • Allocate memmap from hotadded memory
Related show

Commit Message

Oscar Salvador July 25, 2019, 4:02 p.m. UTC
This patch introduces MHP_MEMMAP_ON_MEMORY flag,
and prepares the callers that add memory to take a "flags" parameter.
This "flags" parameter will be evaluated later on in Patch#3
to init mhp_restrictions struct.

The callers are:

add_memory
__add_memory
add_memory_resource

Unfortunately, we do not have a single entry point to add memory, as depending
on the requisites of the caller, they want to hook up in different places,
(e.g: Xen reserve_additional_memory()), so we have to spread the parameter
in the three callers.

MHP_MEMMAP_ON_MEMORY flag parameter will specify to allocate memmaps
from the hot-added range.
If callers wants memmaps to be allocated per memory block, it will
have to call add_memory() variants in memory-block granularity
spanning the whole range, while if it wants to allocate memmaps
per whole memory range, just one call will do.

Want to add 384MB (3 sections, 3 memory-blocks)
e.g:

	add_memory(0x1000, size_memory_block);
	add_memory(0x2000, size_memory_block);
	add_memory(0x3000, size_memory_block);

	[memblock#0  ]
	[0 - 511 pfns      ] - vmemmaps for section#0
	[512 - 32767 pfns  ] - normal memory

	[memblock#1 ]
	[32768 - 33279 pfns] - vmemmaps for section#1
	[33280 - 65535 pfns] - normal memory

	[memblock#2 ]
	[65536 - 66047 pfns] - vmemmap for section#2
	[66048 - 98304 pfns] - normal memory

or
	add_memory(0x1000, size_memory_block * 3);

	[memblock #0 ]
        [0 - 1533 pfns    ] - vmemmap for section#{0-2}
        [1534 - 98304 pfns] - normal memory

When using larger memory blocks (1GB or 2GB), the principle is the same.

Of course, per whole-range granularity is nicer when it comes to have a large
contigous area, while per memory-block granularity allows us to have flexibility
when removing the memory.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
 drivers/acpi/acpi_memhotplug.c |  2 +-
 drivers/base/memory.c          |  2 +-
 drivers/dax/kmem.c             |  2 +-
 drivers/hv/hv_balloon.c        |  2 +-
 drivers/s390/char/sclp_cmd.c   |  2 +-
 drivers/xen/balloon.c          |  2 +-
 include/linux/memory_hotplug.h | 25 ++++++++++++++++++++++---
 mm/memory_hotplug.c            | 10 +++++-----
 8 files changed, 33 insertions(+), 14 deletions(-)

Comments

David Hildenbrand July 26, 2019, 8:34 a.m. UTC | #1
On 25.07.19 18:02, Oscar Salvador wrote:
> This patch introduces MHP_MEMMAP_ON_MEMORY flag,
> and prepares the callers that add memory to take a "flags" parameter.
> This "flags" parameter will be evaluated later on in Patch#3
> to init mhp_restrictions struct.
> 
> The callers are:
> 
> add_memory
> __add_memory
> add_memory_resource
> 
> Unfortunately, we do not have a single entry point to add memory, as depending
> on the requisites of the caller, they want to hook up in different places,
> (e.g: Xen reserve_additional_memory()), so we have to spread the parameter
> in the three callers.
> 
> MHP_MEMMAP_ON_MEMORY flag parameter will specify to allocate memmaps
> from the hot-added range.
> If callers wants memmaps to be allocated per memory block, it will
> have to call add_memory() variants in memory-block granularity
> spanning the whole range, while if it wants to allocate memmaps
> per whole memory range, just one call will do.
> 
> Want to add 384MB (3 sections, 3 memory-blocks)
> e.g:
> 
> 	add_memory(0x1000, size_memory_block);
> 	add_memory(0x2000, size_memory_block);
> 	add_memory(0x3000, size_memory_block);
> 
> 	[memblock#0  ]
> 	[0 - 511 pfns      ] - vmemmaps for section#0
> 	[512 - 32767 pfns  ] - normal memory
> 
> 	[memblock#1 ]
> 	[32768 - 33279 pfns] - vmemmaps for section#1
> 	[33280 - 65535 pfns] - normal memory
> 
> 	[memblock#2 ]
> 	[65536 - 66047 pfns] - vmemmap for section#2
> 	[66048 - 98304 pfns] - normal memory

I wouldn't even care about documenting this right now. We have no user
so far, so spending 50% of the description on this topic isn't really
needed IMHO :)

> 
> or
> 	add_memory(0x1000, size_memory_block * 3);
> 
> 	[memblock #0 ]
>         [0 - 1533 pfns    ] - vmemmap for section#{0-2}
>         [1534 - 98304 pfns] - normal memory
> 
> When using larger memory blocks (1GB or 2GB), the principle is the same.
> 
> Of course, per whole-range granularity is nicer when it comes to have a large
> contigous area, while per memory-block granularity allows us to have flexibility
> when removing the memory.

E.g., in my virtio-mem I am currently adding all memory blocks
separately either way (to guranatee that remove_memory() works cleanly -
see __release_memory_resource()), and to control the amount of
not-offlined memory blocks (e.g., to make user space is actually
onlining them). As it's just a prototype, this might change of course in
the future.

> 
> Signed-off-by: Oscar Salvador <osalvador@suse.de>
> ---
>  drivers/acpi/acpi_memhotplug.c |  2 +-
>  drivers/base/memory.c          |  2 +-
>  drivers/dax/kmem.c             |  2 +-
>  drivers/hv/hv_balloon.c        |  2 +-
>  drivers/s390/char/sclp_cmd.c   |  2 +-
>  drivers/xen/balloon.c          |  2 +-
>  include/linux/memory_hotplug.h | 25 ++++++++++++++++++++++---
>  mm/memory_hotplug.c            | 10 +++++-----
>  8 files changed, 33 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> index e294f44a7850..d91b3584d4b2 100644
> --- a/drivers/acpi/acpi_memhotplug.c
> +++ b/drivers/acpi/acpi_memhotplug.c
> @@ -207,7 +207,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
>  		if (node < 0)
>  			node = memory_add_physaddr_to_nid(info->start_addr);
>  
> -		result = __add_memory(node, info->start_addr, info->length);
> +		result = __add_memory(node, info->start_addr, info->length, 0);
>  
>  		/*
>  		 * If the memory block has been used by the kernel, add_memory()
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index 154d5d4a0779..d30d0f6c8ad0 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -521,7 +521,7 @@ static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
>  
>  	nid = memory_add_physaddr_to_nid(phys_addr);
>  	ret = __add_memory(nid, phys_addr,
> -			   MIN_MEMORY_BLOCK_SIZE * sections_per_block);
> +			   MIN_MEMORY_BLOCK_SIZE * sections_per_block, 0);
>  
>  	if (ret)
>  		goto out;
> diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
> index 3d0a7e702c94..e159184e0ba0 100644
> --- a/drivers/dax/kmem.c
> +++ b/drivers/dax/kmem.c
> @@ -65,7 +65,7 @@ int dev_dax_kmem_probe(struct device *dev)
>  	new_res->flags = IORESOURCE_SYSTEM_RAM;
>  	new_res->name = dev_name(dev);
>  
> -	rc = add_memory(numa_node, new_res->start, resource_size(new_res));
> +	rc = add_memory(numa_node, new_res->start, resource_size(new_res), 0);
>  	if (rc) {
>  		release_resource(new_res);
>  		kfree(new_res);
> diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
> index 6fb4ea5f0304..beb92bc56186 100644
> --- a/drivers/hv/hv_balloon.c
> +++ b/drivers/hv/hv_balloon.c
> @@ -731,7 +731,7 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size,
>  
>  		nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn));
>  		ret = add_memory(nid, PFN_PHYS((start_pfn)),
> -				(HA_CHUNK << PAGE_SHIFT));
> +				(HA_CHUNK << PAGE_SHIFT), 0);
>  
>  		if (ret) {
>  			pr_err("hot_add memory failed error is %d\n", ret);
> diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
> index 37d42de06079..f61026c7db7e 100644
> --- a/drivers/s390/char/sclp_cmd.c
> +++ b/drivers/s390/char/sclp_cmd.c
> @@ -406,7 +406,7 @@ static void __init add_memory_merged(u16 rn)
>  	if (!size)
>  		goto skip_add;
>  	for (addr = start; addr < start + size; addr += block_size)
> -		add_memory(numa_pfn_to_nid(PFN_DOWN(addr)), addr, block_size);
> +		add_memory(numa_pfn_to_nid(PFN_DOWN(addr)), addr, block_size, 0);
>  skip_add:
>  	first_rn = rn;
>  	num = 1;
> diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
> index 4e11de6cde81..e4934ce40478 100644
> --- a/drivers/xen/balloon.c
> +++ b/drivers/xen/balloon.c
> @@ -349,7 +349,7 @@ static enum bp_state reserve_additional_memory(void)
>  	mutex_unlock(&balloon_mutex);
>  	/* add_memory_resource() requires the device_hotplug lock */
>  	lock_device_hotplug();
> -	rc = add_memory_resource(nid, resource);
> +	rc = add_memory_resource(nid, resource, 0);
>  	unlock_device_hotplug();
>  	mutex_lock(&balloon_mutex);
>  
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index f46ea71b4ffd..45dece922d7c 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -54,6 +54,25 @@ enum {
>  };
>  
>  /*
> + * We want memmap (struct page array) to be allocated from the hotadded range.
> + * To do so, there are two possible ways depending on what the caller wants.
> + * 1) Allocate memmap pages whole hot-added range.
> + *    Here the caller will only call any add_memory() variant with the whole
> + *    memory address.
> + * 2) Allocate memmap pages per memblock
> + *    Here, the caller will call any add_memory() variant per memblock
> + *    granularity.
> + * The former implies that we will use the beginning of the hot-added range
> + * to store the memmap pages of the whole range, while the latter implies
> + * that we will use the beginning of each memblock to store its own memmap
> + * pages.

Can you make this documentation only state how MHP_MEMMAP_ON_MEMORY
works? (IOW, shrink it heavily to what we actually implement)

> + *
> + * Please note that this is only a hint, not a guarantee. Only selected
> + * architectures support it with SPARSE_VMEMMAP.
> + */
> +#define MHP_MEMMAP_ON_MEMORY	(1UL<<1)
> +
> +/*
>   * Restrictions for the memory hotplug:
>   * flags:  MHP_ flags
>   * altmap: alternative allocator for memmap array
> @@ -340,9 +359,9 @@ static inline void __remove_memory(int nid, u64 start, u64 size) {}
>  #endif /* CONFIG_MEMORY_HOTREMOVE */
>  
>  extern void __ref free_area_init_core_hotplug(int nid);
> -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 __add_memory(int nid, u64 start, u64 size, unsigned long flags);
> +extern int add_memory(int nid, u64 start, u64 size, unsigned long flags);
> +extern int add_memory_resource(int nid, struct resource *resource, unsigned long flags);
>  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/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 9a82e12bd0e7..3d97c3711333 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1046,7 +1046,7 @@ static int online_memory_block(struct memory_block *mem, void *arg)
>   *
>   * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG
>   */
> -int __ref add_memory_resource(int nid, struct resource *res)
> +int __ref add_memory_resource(int nid, struct resource *res, unsigned long flags)
>  {
>  	struct mhp_restrictions restrictions = {};
>  	u64 start, size;
> @@ -1123,7 +1123,7 @@ int __ref add_memory_resource(int nid, struct resource *res)
>  }
>  
>  /* requires device_hotplug_lock, see add_memory_resource() */
> -int __ref __add_memory(int nid, u64 start, u64 size)
> +int __ref __add_memory(int nid, u64 start, u64 size, unsigned long flags)
>  {
>  	struct resource *res;
>  	int ret;
> @@ -1132,18 +1132,18 @@ int __ref __add_memory(int nid, u64 start, u64 size)
>  	if (IS_ERR(res))
>  		return PTR_ERR(res);
>  
> -	ret = add_memory_resource(nid, res);
> +	ret = add_memory_resource(nid, res, flags);
>  	if (ret < 0)
>  		release_memory_resource(res);
>  	return ret;
>  }
>  
> -int add_memory(int nid, u64 start, u64 size)
> +int add_memory(int nid, u64 start, u64 size, unsigned long flags)
>  {
>  	int rc;
>  
>  	lock_device_hotplug();
> -	rc = __add_memory(nid, start, size);
> +	rc = __add_memory(nid, start, size, flags);
>  	unlock_device_hotplug();
>  
>  	return rc;
> 

Apart from the requested description/documentation changes

Reviewed-by: David Hildenbrand <david@redhat.com>
Oscar Salvador July 26, 2019, 9:29 a.m. UTC | #2
On Fri, Jul 26, 2019 at 10:34:47AM +0200, David Hildenbrand wrote:
> > Want to add 384MB (3 sections, 3 memory-blocks)
> > e.g:
> > 
> > 	add_memory(0x1000, size_memory_block);
> > 	add_memory(0x2000, size_memory_block);
> > 	add_memory(0x3000, size_memory_block);
> > 
> > 	[memblock#0  ]
> > 	[0 - 511 pfns      ] - vmemmaps for section#0
> > 	[512 - 32767 pfns  ] - normal memory
> > 
> > 	[memblock#1 ]
> > 	[32768 - 33279 pfns] - vmemmaps for section#1
> > 	[33280 - 65535 pfns] - normal memory
> > 
> > 	[memblock#2 ]
> > 	[65536 - 66047 pfns] - vmemmap for section#2
> > 	[66048 - 98304 pfns] - normal memory
> 
> I wouldn't even care about documenting this right now. We have no user
> so far, so spending 50% of the description on this topic isn't really
> needed IMHO :)

Fair enough, I could drop it.
Was just trying to be extra clear.

> 
> > 
> > or
> > 	add_memory(0x1000, size_memory_block * 3);
> > 
> > 	[memblock #0 ]
> >         [0 - 1533 pfns    ] - vmemmap for section#{0-2}
> >         [1534 - 98304 pfns] - normal memory
> > 
> > When using larger memory blocks (1GB or 2GB), the principle is the same.
> > 
> > Of course, per whole-range granularity is nicer when it comes to have a large
> > contigous area, while per memory-block granularity allows us to have flexibility
> > when removing the memory.
> 
> E.g., in my virtio-mem I am currently adding all memory blocks
> separately either way (to guranatee that remove_memory() works cleanly -
> see __release_memory_resource()), and to control the amount of
> not-offlined memory blocks (e.g., to make user space is actually
> onlining them). As it's just a prototype, this might change of course in
> the future.

What is virtio-mem for? Did it that raised from a need?
Is it something you could try this patch on?

> >  /*
> > + * We want memmap (struct page array) to be allocated from the hotadded range.
> > + * To do so, there are two possible ways depending on what the caller wants.
> > + * 1) Allocate memmap pages whole hot-added range.
> > + *    Here the caller will only call any add_memory() variant with the whole
> > + *    memory address.
> > + * 2) Allocate memmap pages per memblock
> > + *    Here, the caller will call any add_memory() variant per memblock
> > + *    granularity.
> > + * The former implies that we will use the beginning of the hot-added range
> > + * to store the memmap pages of the whole range, while the latter implies
> > + * that we will use the beginning of each memblock to store its own memmap
> > + * pages.
> 
> Can you make this documentation only state how MHP_MEMMAP_ON_MEMORY
> works? (IOW, shrink it heavily to what we actually implement)

Sure.

> Apart from the requested description/documentation changes
> 
> Reviewed-by: David Hildenbrand <david@redhat.com>

Thanks for having a look David ;-)
> 
> -- 
> 
> Thanks,
> 
> David / dhildenb
David Hildenbrand July 26, 2019, 9:37 a.m. UTC | #3
>>
>>>
>>> or
>>> 	add_memory(0x1000, size_memory_block * 3);
>>>
>>> 	[memblock #0 ]
>>>         [0 - 1533 pfns    ] - vmemmap for section#{0-2}
>>>         [1534 - 98304 pfns] - normal memory
>>>
>>> When using larger memory blocks (1GB or 2GB), the principle is the same.
>>>
>>> Of course, per whole-range granularity is nicer when it comes to have a large
>>> contigous area, while per memory-block granularity allows us to have flexibility
>>> when removing the memory.
>>
>> E.g., in my virtio-mem I am currently adding all memory blocks
>> separately either way (to guranatee that remove_memory() works cleanly -
>> see __release_memory_resource()), and to control the amount of
>> not-offlined memory blocks (e.g., to make user space is actually
>> onlining them). As it's just a prototype, this might change of course in
>> the future.
> 
> What is virtio-mem for? Did it that raised from a need?
> Is it something you could try this patch on?

virtio-mem is a paravirtualized way of hotplugging/removing to/from a
guest. (similar to, but different to e.g., the hv-balloon). It
adds/removes memory to/from the system. In the long term, it will try to
also act similar-but different to a balloon - but that will require more
work. In the first shot, it's all about adding/removing memory in the
smaller granularity possible.

The old prototype was

https://lwn.net/Articles/755423/

Since then, a lot changed. Some more updated information is at

https://events.linuxfoundation.org/wp-content/uploads/2017/12/virtio-mem-Paravirtualized-Memory-David-Hildenbrand-Red-Hat-1.pdf

There is also a recording of the presentation on youtube.

The current prototype is unfortunately not in a state yet that allows me
to test with this patch set - my Master's thesis consumed most of my
energy during the last year. I just started hacking on it again.

Patch
diff mbox series

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index e294f44a7850..d91b3584d4b2 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -207,7 +207,7 @@  static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 		if (node < 0)
 			node = memory_add_physaddr_to_nid(info->start_addr);
 
-		result = __add_memory(node, info->start_addr, info->length);
+		result = __add_memory(node, info->start_addr, info->length, 0);
 
 		/*
 		 * If the memory block has been used by the kernel, add_memory()
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 154d5d4a0779..d30d0f6c8ad0 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -521,7 +521,7 @@  static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
 
 	nid = memory_add_physaddr_to_nid(phys_addr);
 	ret = __add_memory(nid, phys_addr,
-			   MIN_MEMORY_BLOCK_SIZE * sections_per_block);
+			   MIN_MEMORY_BLOCK_SIZE * sections_per_block, 0);
 
 	if (ret)
 		goto out;
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index 3d0a7e702c94..e159184e0ba0 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -65,7 +65,7 @@  int dev_dax_kmem_probe(struct device *dev)
 	new_res->flags = IORESOURCE_SYSTEM_RAM;
 	new_res->name = dev_name(dev);
 
-	rc = add_memory(numa_node, new_res->start, resource_size(new_res));
+	rc = add_memory(numa_node, new_res->start, resource_size(new_res), 0);
 	if (rc) {
 		release_resource(new_res);
 		kfree(new_res);
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 6fb4ea5f0304..beb92bc56186 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -731,7 +731,7 @@  static void hv_mem_hot_add(unsigned long start, unsigned long size,
 
 		nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn));
 		ret = add_memory(nid, PFN_PHYS((start_pfn)),
-				(HA_CHUNK << PAGE_SHIFT));
+				(HA_CHUNK << PAGE_SHIFT), 0);
 
 		if (ret) {
 			pr_err("hot_add memory failed error is %d\n", ret);
diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index 37d42de06079..f61026c7db7e 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -406,7 +406,7 @@  static void __init add_memory_merged(u16 rn)
 	if (!size)
 		goto skip_add;
 	for (addr = start; addr < start + size; addr += block_size)
-		add_memory(numa_pfn_to_nid(PFN_DOWN(addr)), addr, block_size);
+		add_memory(numa_pfn_to_nid(PFN_DOWN(addr)), addr, block_size, 0);
 skip_add:
 	first_rn = rn;
 	num = 1;
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 4e11de6cde81..e4934ce40478 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -349,7 +349,7 @@  static enum bp_state reserve_additional_memory(void)
 	mutex_unlock(&balloon_mutex);
 	/* add_memory_resource() requires the device_hotplug lock */
 	lock_device_hotplug();
-	rc = add_memory_resource(nid, resource);
+	rc = add_memory_resource(nid, resource, 0);
 	unlock_device_hotplug();
 	mutex_lock(&balloon_mutex);
 
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index f46ea71b4ffd..45dece922d7c 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -54,6 +54,25 @@  enum {
 };
 
 /*
+ * We want memmap (struct page array) to be allocated from the hotadded range.
+ * To do so, there are two possible ways depending on what the caller wants.
+ * 1) Allocate memmap pages whole hot-added range.
+ *    Here the caller will only call any add_memory() variant with the whole
+ *    memory address.
+ * 2) Allocate memmap pages per memblock
+ *    Here, the caller will call any add_memory() variant per memblock
+ *    granularity.
+ * The former implies that we will use the beginning of the hot-added range
+ * to store the memmap pages of the whole range, while the latter implies
+ * that we will use the beginning of each memblock to store its own memmap
+ * pages.
+ *
+ * Please note that this is only a hint, not a guarantee. Only selected
+ * architectures support it with SPARSE_VMEMMAP.
+ */
+#define MHP_MEMMAP_ON_MEMORY	(1UL<<1)
+
+/*
  * Restrictions for the memory hotplug:
  * flags:  MHP_ flags
  * altmap: alternative allocator for memmap array
@@ -340,9 +359,9 @@  static inline void __remove_memory(int nid, u64 start, u64 size) {}
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
 extern void __ref free_area_init_core_hotplug(int nid);
-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 __add_memory(int nid, u64 start, u64 size, unsigned long flags);
+extern int add_memory(int nid, u64 start, u64 size, unsigned long flags);
+extern int add_memory_resource(int nid, struct resource *resource, unsigned long flags);
 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/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 9a82e12bd0e7..3d97c3711333 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1046,7 +1046,7 @@  static int online_memory_block(struct memory_block *mem, void *arg)
  *
  * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG
  */
-int __ref add_memory_resource(int nid, struct resource *res)
+int __ref add_memory_resource(int nid, struct resource *res, unsigned long flags)
 {
 	struct mhp_restrictions restrictions = {};
 	u64 start, size;
@@ -1123,7 +1123,7 @@  int __ref add_memory_resource(int nid, struct resource *res)
 }
 
 /* requires device_hotplug_lock, see add_memory_resource() */
-int __ref __add_memory(int nid, u64 start, u64 size)
+int __ref __add_memory(int nid, u64 start, u64 size, unsigned long flags)
 {
 	struct resource *res;
 	int ret;
@@ -1132,18 +1132,18 @@  int __ref __add_memory(int nid, u64 start, u64 size)
 	if (IS_ERR(res))
 		return PTR_ERR(res);
 
-	ret = add_memory_resource(nid, res);
+	ret = add_memory_resource(nid, res, flags);
 	if (ret < 0)
 		release_memory_resource(res);
 	return ret;
 }
 
-int add_memory(int nid, u64 start, u64 size)
+int add_memory(int nid, u64 start, u64 size, unsigned long flags)
 {
 	int rc;
 
 	lock_device_hotplug();
-	rc = __add_memory(nid, start, size);
+	rc = __add_memory(nid, start, size, flags);
 	unlock_device_hotplug();
 
 	return rc;