[v1,2/7] s390x/mm: Implement arch_remove_memory()
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Message ID 20190424102511.29318-3-david@redhat.com
State New
Headers show
Series
  • [v1,1/7] mm/memory_hotplug: Simplify and fix check_hotplug_memory_range()
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Commit Message

David Hildenbrand April 24, 2019, 10:25 a.m. UTC
Will come in handy when wanting to handle errors after
arch_add_memory().

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/s390/mm/init.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

Comments

David Hildenbrand April 26, 2019, 9:11 a.m. UTC | #1
On 24.04.19 12:25, David Hildenbrand wrote:
> Will come in handy when wanting to handle errors after
> arch_add_memory().
> 
> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Vasily Gorbik <gor@linux.ibm.com>
> Cc: Oscar Salvador <osalvador@suse.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  arch/s390/mm/init.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index 31b1071315d7..2636d62df04e 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -237,12 +237,13 @@ int arch_add_memory(int nid, u64 start, u64 size,
>  void arch_remove_memory(int nid, u64 start, u64 size,
>  			struct vmem_altmap *altmap)
>  {
> -	/*
> -	 * There is no hardware or firmware interface which could trigger a
> -	 * hot memory remove on s390. So there is nothing that needs to be
> -	 * implemented.
> -	 */
> -	BUG();
> +	unsigned long start_pfn = start >> PAGE_SHIFT;
> +	unsigned long nr_pages = size >> PAGE_SHIFT;
> +	struct zone *zone;
> +
> +	vmem_remove_mapping(start, size);
> +	zone = page_zone(pfn_to_page(start_pfn));
> +	__remove_pages(zone, start_pfn, nr_pages, altmap);

I guess the correct way is to remove the mapping after __remove_pages.
But as the pages should not be touched by anybody, it shouldn't really
matter. Will change when I resend.

>  }
>  #endif
>  #endif /* CONFIG_MEMORY_HOTPLUG */
>

Patch
diff mbox series

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 31b1071315d7..2636d62df04e 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -237,12 +237,13 @@  int arch_add_memory(int nid, u64 start, u64 size,
 void arch_remove_memory(int nid, u64 start, u64 size,
 			struct vmem_altmap *altmap)
 {
-	/*
-	 * There is no hardware or firmware interface which could trigger a
-	 * hot memory remove on s390. So there is nothing that needs to be
-	 * implemented.
-	 */
-	BUG();
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long nr_pages = size >> PAGE_SHIFT;
+	struct zone *zone;
+
+	vmem_remove_mapping(start, size);
+	zone = page_zone(pfn_to_page(start_pfn));
+	__remove_pages(zone, start_pfn, nr_pages, altmap);
 }
 #endif
 #endif /* CONFIG_MEMORY_HOTPLUG */