Patchwork [v4,05/12] memory-hotplug: introduce new function arch_remove_memory() for removing page table depends on architecture

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Submitter Wen Congyang
Date Nov. 27, 2012, 10 a.m.
Message ID <1354010422-19648-6-git-send-email-wency@cn.fujitsu.com>
Download mbox | patch
Permalink /patch/202145/
State Not Applicable
Delegated to: David Miller
Headers show

Comments

Wen Congyang - Nov. 27, 2012, 10 a.m.
For removing memory, we need to remove page table. But it depends
on architecture. So the patch introduce arch_remove_memory() for
removing page table. Now it only calls __remove_pages().

Note: __remove_pages() for some archtecuture is not implemented
      (I don't know how to implement it for s390).

CC: David Rientjes <rientjes@google.com>
CC: Jiang Liu <liuj97@gmail.com>
CC: Len Brown <len.brown@intel.com>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
CC: Christoph Lameter <cl@linux.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
CC: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
 arch/ia64/mm/init.c            | 18 ++++++++++++++++++
 arch/powerpc/mm/mem.c          | 12 ++++++++++++
 arch/s390/mm/init.c            | 12 ++++++++++++
 arch/sh/mm/init.c              | 17 +++++++++++++++++
 arch/tile/mm/init.c            |  8 ++++++++
 arch/x86/mm/init_32.c          | 12 ++++++++++++
 arch/x86/mm/init_64.c          | 15 +++++++++++++++
 include/linux/memory_hotplug.h |  1 +
 mm/memory_hotplug.c            |  2 ++
 9 files changed, 97 insertions(+)
Tang Chen - Dec. 4, 2012, 9:30 a.m.
On 11/27/2012 06:00 PM, Wen Congyang wrote:
> For removing memory, we need to remove page table. But it depends
> on architecture. So the patch introduce arch_remove_memory() for
> removing page table. Now it only calls __remove_pages().
>
> Note: __remove_pages() for some archtecuture is not implemented
>        (I don't know how to implement it for s390).
>
> CC: David Rientjes<rientjes@google.com>
> CC: Jiang Liu<liuj97@gmail.com>
> CC: Len Brown<len.brown@intel.com>
> CC: Benjamin Herrenschmidt<benh@kernel.crashing.org>
> CC: Paul Mackerras<paulus@samba.org>
> CC: Christoph Lameter<cl@linux.com>
> Cc: Minchan Kim<minchan.kim@gmail.com>
> CC: Andrew Morton<akpm@linux-foundation.org>
> CC: KOSAKI Motohiro<kosaki.motohiro@jp.fujitsu.com>
> CC: Yasuaki Ishimatsu<isimatu.yasuaki@jp.fujitsu.com>
> Signed-off-by: Wen Congyang<wency@cn.fujitsu.com>
> ---
>   arch/ia64/mm/init.c            | 18 ++++++++++++++++++
>   arch/powerpc/mm/mem.c          | 12 ++++++++++++
>   arch/s390/mm/init.c            | 12 ++++++++++++
>   arch/sh/mm/init.c              | 17 +++++++++++++++++
>   arch/tile/mm/init.c            |  8 ++++++++
>   arch/x86/mm/init_32.c          | 12 ++++++++++++
>   arch/x86/mm/init_64.c          | 15 +++++++++++++++
>   include/linux/memory_hotplug.h |  1 +
>   mm/memory_hotplug.c            |  2 ++
>   9 files changed, 97 insertions(+)
>
> diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
> index 082e383..e333822 100644
> --- a/arch/ia64/mm/init.c
> +++ b/arch/ia64/mm/init.c
> @@ -689,6 +689,24 @@ int arch_add_memory(int nid, u64 start, u64 size)
>
>   	return ret;
>   }
> +
> +#ifdef CONFIG_MEMORY_HOTREMOVE
> +int arch_remove_memory(u64 start, u64 size)
> +{
> +	unsigned long start_pfn = start>>  PAGE_SHIFT;
> +	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);
> +	if (ret)
> +		pr_warn("%s: Problem encountered in __remove_pages() as"
> +			" ret=%d\n", __func__,  ret);
> +
> +	return ret;

Just a little question, why do we have different handlers for ret on
different platforms ?  Sometimes we print a msg, sometimes we just
return, and sometimes we give a WARN_ON(). But no big deal. :)

Reviewed-by: Tang Chen <tangchen@cn.fujitsu.com>

> +}
> +#endif
>   #endif
>
>   /*
> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> index 0dba506..09c6451 100644
> --- a/arch/powerpc/mm/mem.c
> +++ b/arch/powerpc/mm/mem.c
> @@ -133,6 +133,18 @@ int arch_add_memory(int nid, u64 start, u64 size)
>
>   	return __add_pages(nid, zone, start_pfn, nr_pages);
>   }
> +
> +#ifdef CONFIG_MEMORY_HOTREMOVE
> +int arch_remove_memory(u64 start, u64 size)
> +{
> +	unsigned long start_pfn = start>>  PAGE_SHIFT;
> +	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);
> +}
> +#endif
>   #endif /* CONFIG_MEMORY_HOTPLUG */
>
>   /*
> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index 81e596c..b565190 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -257,4 +257,16 @@ int arch_add_memory(int nid, u64 start, u64 size)
>   		vmem_remove_mapping(start, size);
>   	return rc;
>   }
> +
> +#ifdef CONFIG_MEMORY_HOTREMOVE
> +int arch_remove_memory(u64 start, u64 size)
> +{
> +	/*
> +	 * 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.
> +	 */
> +	return -EBUSY;
> +}
> +#endif
>   #endif /* CONFIG_MEMORY_HOTPLUG */
> diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
> index 82cc576..1057940 100644
> --- a/arch/sh/mm/init.c
> +++ b/arch/sh/mm/init.c
> @@ -558,4 +558,21 @@ int memory_add_physaddr_to_nid(u64 addr)
>   EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
>   #endif
>
> +#ifdef CONFIG_MEMORY_HOTREMOVE
> +int arch_remove_memory(u64 start, u64 size)
> +{
> +	unsigned long start_pfn = start>>  PAGE_SHIFT;
> +	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);
> +	if (unlikely(ret))
> +		pr_warn("%s: Failed, __remove_pages() == %d\n", __func__,
> +			ret);
> +
> +	return ret;
> +}
> +#endif
>   #endif /* CONFIG_MEMORY_HOTPLUG */
> diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c
> index ef29d6c..2749515 100644
> --- a/arch/tile/mm/init.c
> +++ b/arch/tile/mm/init.c
> @@ -935,6 +935,14 @@ int remove_memory(u64 start, u64 size)
>   {
>   	return -EINVAL;
>   }
> +
> +#ifdef CONFIG_MEMORY_HOTREMOVE
> +int arch_remove_memory(u64 start, u64 size)
> +{
> +	/* TODO */
> +	return -EBUSY;
> +}
> +#endif
>   #endif
>
>   struct kmem_cache *pgd_cache;
> diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
> index 11a5800..b19eba4 100644
> --- a/arch/x86/mm/init_32.c
> +++ b/arch/x86/mm/init_32.c
> @@ -839,6 +839,18 @@ int arch_add_memory(int nid, u64 start, u64 size)
>
>   	return __add_pages(nid, zone, start_pfn, nr_pages);
>   }
> +
> +#ifdef CONFIG_MEMORY_HOTREMOVE
> +int arch_remove_memory(u64 start, u64 size)
> +{
> +	unsigned long start_pfn = start>>  PAGE_SHIFT;
> +	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);
> +}
> +#endif
>   #endif
>
>   /*
> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> index 3baff25..5675335 100644
> --- a/arch/x86/mm/init_64.c
> +++ b/arch/x86/mm/init_64.c
> @@ -680,6 +680,21 @@ int arch_add_memory(int nid, u64 start, u64 size)
>   }
>   EXPORT_SYMBOL_GPL(arch_add_memory);
>
> +#ifdef CONFIG_MEMORY_HOTREMOVE
> +int __ref arch_remove_memory(u64 start, u64 size)
> +{
> +	unsigned long start_pfn = start>>  PAGE_SHIFT;
> +	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);
> +	WARN_ON_ONCE(ret);
> +
> +	return ret;
> +}
> +#endif
>   #endif /* CONFIG_MEMORY_HOTPLUG */
>
>   static struct kcore_list kcore_vsyscall;
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index 38675e9..191b2d9 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -85,6 +85,7 @@ extern void __online_page_free(struct page *page);
>
>   #ifdef CONFIG_MEMORY_HOTREMOVE
>   extern bool is_pageblock_removable_nolock(struct page *page);
> +extern int arch_remove_memory(u64 start, u64 size);
>   #endif /* CONFIG_MEMORY_HOTREMOVE */
>
>   /* reasonably generic interface to expand the physical pages in a zone  */
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 63d5388..e741732 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1111,6 +1111,8 @@ repeat:
>   	/* remove memmap entry */
>   	firmware_map_remove(start, start + size, "System RAM");
>
> +	arch_remove_memory(start, size);
> +
>   	unlock_memory_hotplug();
>
>   	return 0;

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Patch

diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 082e383..e333822 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -689,6 +689,24 @@  int arch_add_memory(int nid, u64 start, u64 size)
 
 	return ret;
 }
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int arch_remove_memory(u64 start, u64 size)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	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);
+	if (ret)
+		pr_warn("%s: Problem encountered in __remove_pages() as"
+			" ret=%d\n", __func__,  ret);
+
+	return ret;
+}
+#endif
 #endif
 
 /*
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 0dba506..09c6451 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -133,6 +133,18 @@  int arch_add_memory(int nid, u64 start, u64 size)
 
 	return __add_pages(nid, zone, start_pfn, nr_pages);
 }
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int arch_remove_memory(u64 start, u64 size)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	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);
+}
+#endif
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
 /*
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 81e596c..b565190 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -257,4 +257,16 @@  int arch_add_memory(int nid, u64 start, u64 size)
 		vmem_remove_mapping(start, size);
 	return rc;
 }
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int arch_remove_memory(u64 start, u64 size)
+{
+	/*
+	 * 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.
+	 */
+	return -EBUSY;
+}
+#endif
 #endif /* CONFIG_MEMORY_HOTPLUG */
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 82cc576..1057940 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -558,4 +558,21 @@  int memory_add_physaddr_to_nid(u64 addr)
 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 #endif
 
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int arch_remove_memory(u64 start, u64 size)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	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);
+	if (unlikely(ret))
+		pr_warn("%s: Failed, __remove_pages() == %d\n", __func__,
+			ret);
+
+	return ret;
+}
+#endif
 #endif /* CONFIG_MEMORY_HOTPLUG */
diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c
index ef29d6c..2749515 100644
--- a/arch/tile/mm/init.c
+++ b/arch/tile/mm/init.c
@@ -935,6 +935,14 @@  int remove_memory(u64 start, u64 size)
 {
 	return -EINVAL;
 }
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int arch_remove_memory(u64 start, u64 size)
+{
+	/* TODO */
+	return -EBUSY;
+}
+#endif
 #endif
 
 struct kmem_cache *pgd_cache;
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 11a5800..b19eba4 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -839,6 +839,18 @@  int arch_add_memory(int nid, u64 start, u64 size)
 
 	return __add_pages(nid, zone, start_pfn, nr_pages);
 }
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int arch_remove_memory(u64 start, u64 size)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	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);
+}
+#endif
 #endif
 
 /*
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 3baff25..5675335 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -680,6 +680,21 @@  int arch_add_memory(int nid, u64 start, u64 size)
 }
 EXPORT_SYMBOL_GPL(arch_add_memory);
 
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int __ref arch_remove_memory(u64 start, u64 size)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	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);
+	WARN_ON_ONCE(ret);
+
+	return ret;
+}
+#endif
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
 static struct kcore_list kcore_vsyscall;
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 38675e9..191b2d9 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -85,6 +85,7 @@  extern void __online_page_free(struct page *page);
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
 extern bool is_pageblock_removable_nolock(struct page *page);
+extern int arch_remove_memory(u64 start, u64 size);
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
 /* reasonably generic interface to expand the physical pages in a zone  */
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 63d5388..e741732 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1111,6 +1111,8 @@  repeat:
 	/* remove memmap entry */
 	firmware_map_remove(start, start + size, "System RAM");
 
+	arch_remove_memory(start, size);
+
 	unlock_memory_hotplug();
 
 	return 0;