[v2,6/8] mm/memory_hotplug: Remove memory block devices before arch_remove_memory()
diff mbox series

Message ID 20190507183804.5512-7-david@redhat.com
State New
Headers show
Series
  • [v2,1/8] mm/memory_hotplug: Simplify and fix check_hotplug_memory_range()
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Commit Message

David Hildenbrand May 7, 2019, 6:38 p.m. UTC
Let's factor out removing of memory block devices, which is only
necessary for memory added via add_memory() and friends that created
memory block devices. Remove the devices before calling
arch_remove_memory().

This finishes factoring out memory block device handling from
arch_add_memory() and arch_remove_memory().

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Mathieu Malaterre <malat@debian.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 drivers/base/memory.c  | 39 +++++++++++++++++++--------------------
 drivers/base/node.c    | 11 ++++++-----
 include/linux/memory.h |  2 +-
 include/linux/node.h   |  6 ++----
 mm/memory_hotplug.c    |  5 +++--
 5 files changed, 31 insertions(+), 32 deletions(-)

Comments

Dan Williams May 7, 2019, 9:27 p.m. UTC | #1
On Tue, May 7, 2019 at 11:39 AM David Hildenbrand <david@redhat.com> wrote:
>
> Let's factor out removing of memory block devices, which is only
> necessary for memory added via add_memory() and friends that created
> memory block devices. Remove the devices before calling
> arch_remove_memory().
>
> This finishes factoring out memory block device handling from
> arch_add_memory() and arch_remove_memory().

Also nice! makes it easier in the future for the "device-memory" use
case to not avoid messing up the typical memory hotplug flow.

>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Andrew Banman <andrew.banman@hpe.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Mark Brown <broonie@kernel.org>
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
> Cc: Arun KS <arunks@codeaurora.org>
> Cc: Mathieu Malaterre <malat@debian.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  drivers/base/memory.c  | 39 +++++++++++++++++++--------------------
>  drivers/base/node.c    | 11 ++++++-----
>  include/linux/memory.h |  2 +-
>  include/linux/node.h   |  6 ++----
>  mm/memory_hotplug.c    |  5 +++--
>  5 files changed, 31 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index 862c202a18ca..47ff49058d1f 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -756,32 +756,31 @@ int hotplug_memory_register(unsigned long start, unsigned long size)
>         return ret;
>  }
>
> -static int remove_memory_section(struct mem_section *section)
> +/*
> + * Remove memory block devices for the given memory area. Start and size
> + * have to be aligned to memory block granularity. Memory block devices
> + * have to be offline.
> + */
> +void hotplug_memory_unregister(unsigned long start, unsigned long size)
>  {
> +       unsigned long block_nr_pages = memory_block_size_bytes() >> PAGE_SHIFT;
> +       unsigned long start_pfn = PFN_DOWN(start);
> +       unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT);
>         struct memory_block *mem;
> +       unsigned long pfn;
>
> -       if (WARN_ON_ONCE(!present_section(section)))
> -               return;
> +       BUG_ON(!IS_ALIGNED(start, memory_block_size_bytes()));
> +       BUG_ON(!IS_ALIGNED(size, memory_block_size_bytes()));

Similar BUG_ON vs comments WARN_ON comments as the previous patch.

>
>         mutex_lock(&mem_sysfs_mutex);
> -
> -       /*
> -        * Some users of the memory hotplug do not want/need memblock to
> -        * track all sections. Skip over those.
> -        */
> -       mem = find_memory_block(section);
> -       if (!mem)
> -               goto out_unlock;
> -
> -       unregister_mem_sect_under_nodes(mem, __section_nr(section));
> -
> -       mem->section_count--;
> -       if (mem->section_count == 0)
> +       for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) {
> +               mem = find_memory_block(__pfn_to_section(pfn));
> +               if (!mem)
> +                       continue;
> +               mem->section_count = 0;
> +               unregister_memory_block_under_nodes(mem);
>                 unregister_memory(mem);
> -       else
> -               put_device(&mem->dev);
> -
> -out_unlock:
> +       }
>         mutex_unlock(&mem_sysfs_mutex);
>  }
>
> diff --git a/drivers/base/node.c b/drivers/base/node.c
> index 8598fcbd2a17..04fdfa99b8bc 100644
> --- a/drivers/base/node.c
> +++ b/drivers/base/node.c
> @@ -801,9 +801,10 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg)
>         return 0;
>  }
>
> -/* unregister memory section under all nodes that it spans */
> -int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
> -                                   unsigned long phys_index)
> +/*
> + * Unregister memory block device under all nodes that it spans.
> + */
> +int unregister_memory_block_under_nodes(struct memory_block *mem_blk)
>  {
>         NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
>         unsigned long pfn, sect_start_pfn, sect_end_pfn;
> @@ -816,8 +817,8 @@ int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
>                 return -ENOMEM;
>         nodes_clear(*unlinked_nodes);
>
> -       sect_start_pfn = section_nr_to_pfn(phys_index);
> -       sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
> +       sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
> +       sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
>         for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
>                 int nid;
>
> diff --git a/include/linux/memory.h b/include/linux/memory.h
> index 95505fbb5f85..aa236c2a0466 100644
> --- a/include/linux/memory.h
> +++ b/include/linux/memory.h
> @@ -112,7 +112,7 @@ extern void unregister_memory_notifier(struct notifier_block *nb);
>  extern int register_memory_isolate_notifier(struct notifier_block *nb);
>  extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
>  int hotplug_memory_register(unsigned long start, unsigned long size);
> -extern void unregister_memory_section(struct mem_section *);
> +void hotplug_memory_unregister(unsigned long start, unsigned long size);
>  extern int memory_dev_init(void);
>  extern int memory_notify(unsigned long val, void *v);
>  extern int memory_isolate_notify(unsigned long val, void *v);
> diff --git a/include/linux/node.h b/include/linux/node.h
> index 1a557c589ecb..02a29e71b175 100644
> --- a/include/linux/node.h
> +++ b/include/linux/node.h
> @@ -139,8 +139,7 @@ extern int register_cpu_under_node(unsigned int cpu, unsigned int nid);
>  extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid);
>  extern int register_mem_sect_under_node(struct memory_block *mem_blk,
>                                                 void *arg);
> -extern int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
> -                                          unsigned long phys_index);
> +extern int unregister_memory_block_under_nodes(struct memory_block *mem_blk);
>
>  extern int register_memory_node_under_compute_node(unsigned int mem_nid,
>                                                    unsigned int cpu_nid,
> @@ -176,8 +175,7 @@ static inline int register_mem_sect_under_node(struct memory_block *mem_blk,
>  {
>         return 0;
>  }
> -static inline int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
> -                                                 unsigned long phys_index)
> +static inline int unregister_memory_block_under_nodes(struct memory_block *mem_blk)
>  {
>         return 0;
>  }
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 107f72952347..527fe4f9c620 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -519,8 +519,6 @@ static void __remove_section(struct zone *zone, struct mem_section *ms,
>         if (WARN_ON_ONCE(!valid_section(ms)))
>                 return;
>
> -       unregister_memory_section(ms);
> -
>         scn_nr = __section_nr(ms);
>         start_pfn = section_nr_to_pfn((unsigned long)scn_nr);
>         __remove_zone(zone, start_pfn);
> @@ -1844,6 +1842,9 @@ void __ref __remove_memory(int nid, u64 start, u64 size)
>         memblock_free(start, size);
>         memblock_remove(start, size);
>
> +       /* remove memory block devices before removing memory */
> +       hotplug_memory_unregister(start, size);
> +
>         arch_remove_memory(nid, start, size, NULL);
>         __release_memory_resource(start, size);

Other than the BUG_ON concern you can add

Reviewed-by: Dan Williams <dan.j.williams@intel.com>

Patch
diff mbox series

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 862c202a18ca..47ff49058d1f 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -756,32 +756,31 @@  int hotplug_memory_register(unsigned long start, unsigned long size)
 	return ret;
 }
 
-static int remove_memory_section(struct mem_section *section)
+/*
+ * Remove memory block devices for the given memory area. Start and size
+ * have to be aligned to memory block granularity. Memory block devices
+ * have to be offline.
+ */
+void hotplug_memory_unregister(unsigned long start, unsigned long size)
 {
+	unsigned long block_nr_pages = memory_block_size_bytes() >> PAGE_SHIFT;
+	unsigned long start_pfn = PFN_DOWN(start);
+	unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT);
 	struct memory_block *mem;
+	unsigned long pfn;
 
-	if (WARN_ON_ONCE(!present_section(section)))
-		return;
+	BUG_ON(!IS_ALIGNED(start, memory_block_size_bytes()));
+	BUG_ON(!IS_ALIGNED(size, memory_block_size_bytes()));
 
 	mutex_lock(&mem_sysfs_mutex);
-
-	/*
-	 * Some users of the memory hotplug do not want/need memblock to
-	 * track all sections. Skip over those.
-	 */
-	mem = find_memory_block(section);
-	if (!mem)
-		goto out_unlock;
-
-	unregister_mem_sect_under_nodes(mem, __section_nr(section));
-
-	mem->section_count--;
-	if (mem->section_count == 0)
+	for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) {
+		mem = find_memory_block(__pfn_to_section(pfn));
+		if (!mem)
+			continue;
+		mem->section_count = 0;
+		unregister_memory_block_under_nodes(mem);
 		unregister_memory(mem);
-	else
-		put_device(&mem->dev);
-
-out_unlock:
+	}
 	mutex_unlock(&mem_sysfs_mutex);
 }
 
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 8598fcbd2a17..04fdfa99b8bc 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -801,9 +801,10 @@  int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg)
 	return 0;
 }
 
-/* unregister memory section under all nodes that it spans */
-int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
-				    unsigned long phys_index)
+/*
+ * Unregister memory block device under all nodes that it spans.
+ */
+int unregister_memory_block_under_nodes(struct memory_block *mem_blk)
 {
 	NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
 	unsigned long pfn, sect_start_pfn, sect_end_pfn;
@@ -816,8 +817,8 @@  int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
 		return -ENOMEM;
 	nodes_clear(*unlinked_nodes);
 
-	sect_start_pfn = section_nr_to_pfn(phys_index);
-	sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
+	sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
+	sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
 	for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
 		int nid;
 
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 95505fbb5f85..aa236c2a0466 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -112,7 +112,7 @@  extern void unregister_memory_notifier(struct notifier_block *nb);
 extern int register_memory_isolate_notifier(struct notifier_block *nb);
 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 int hotplug_memory_register(unsigned long start, unsigned long size);
-extern void unregister_memory_section(struct mem_section *);
+void hotplug_memory_unregister(unsigned long start, unsigned long size);
 extern int memory_dev_init(void);
 extern int memory_notify(unsigned long val, void *v);
 extern int memory_isolate_notify(unsigned long val, void *v);
diff --git a/include/linux/node.h b/include/linux/node.h
index 1a557c589ecb..02a29e71b175 100644
--- a/include/linux/node.h
+++ b/include/linux/node.h
@@ -139,8 +139,7 @@  extern int register_cpu_under_node(unsigned int cpu, unsigned int nid);
 extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid);
 extern int register_mem_sect_under_node(struct memory_block *mem_blk,
 						void *arg);
-extern int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
-					   unsigned long phys_index);
+extern int unregister_memory_block_under_nodes(struct memory_block *mem_blk);
 
 extern int register_memory_node_under_compute_node(unsigned int mem_nid,
 						   unsigned int cpu_nid,
@@ -176,8 +175,7 @@  static inline int register_mem_sect_under_node(struct memory_block *mem_blk,
 {
 	return 0;
 }
-static inline int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
-						  unsigned long phys_index)
+static inline int unregister_memory_block_under_nodes(struct memory_block *mem_blk)
 {
 	return 0;
 }
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 107f72952347..527fe4f9c620 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -519,8 +519,6 @@  static void __remove_section(struct zone *zone, struct mem_section *ms,
 	if (WARN_ON_ONCE(!valid_section(ms)))
 		return;
 
-	unregister_memory_section(ms);
-
 	scn_nr = __section_nr(ms);
 	start_pfn = section_nr_to_pfn((unsigned long)scn_nr);
 	__remove_zone(zone, start_pfn);
@@ -1844,6 +1842,9 @@  void __ref __remove_memory(int nid, u64 start, u64 size)
 	memblock_free(start, size);
 	memblock_remove(start, size);
 
+	/* remove memory block devices before removing memory */
+	hotplug_memory_unregister(start, size);
+
 	arch_remove_memory(nid, start, size, NULL);
 	__release_memory_resource(start, size);