[RFC PATCH 6/8] memory-hotplug: introduce new function arch_remove_memory()
From: Wen Congyang
Date: Fri Jul 20 2012 - 03:07:34 EST
We don't call __add_pages() directly in the function add_memory()
because some other architecture related thins needs to be done
before or after calling __add_pages(). So we should not call
__remove_pages() directly in the function remove_memory.
Introduce new function arch_remove_memory() to revert the things done
in arch_add_memory().
Note: the function for x86_64 will be implemented later. And I don't
know how to implement it for s390.
CC: David Rientjes <rientjes@xxxxxxxxxx>
CC: Jiang Liu <liuj97@xxxxxxxxx>
CC: Len Brown <len.brown@xxxxxxxxx>
CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Christoph Lameter <cl@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
CC: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
arch/ia64/mm/init.c | 16 ++++++++++++++++
arch/powerpc/mm/mem.c | 14 ++++++++++++++
arch/s390/mm/init.c | 8 ++++++++
arch/sh/mm/init.c | 15 +++++++++++++++
arch/tile/mm/init.c | 8 ++++++++
arch/x86/mm/init_32.c | 10 ++++++++++
arch/x86/mm/init_64.c | 7 +++++++
include/linux/memory_hotplug.h | 1 +
mm/memory_hotplug.c | 2 +-
9 files changed, 80 insertions(+), 1 deletions(-)
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 0eab454..1e345ed 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -688,6 +688,22 @@ 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;
+ int ret;
+
+ ret = __remove_pages(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 baaafde..249cef4 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -133,6 +133,20 @@ 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;
+
+ start = (unsigned long)__va(start);
+ if (remove_section_mapping(start, start + size))
+ return -EINVAL;
+
+ return __remove_pages(start_pfn, nr_pages);
+}
+#endif
#endif /* CONFIG_MEMORY_HOTPLUG */
/*
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 2bea060..3de0d5b 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -259,4 +259,12 @@ 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)
+{
+ /* TODO */
+ return -EBUSY;
+}
+#endif
#endif /* CONFIG_MEMORY_HOTPLUG */
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 82cc576..fc84491 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -558,4 +558,19 @@ 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;
+ int ret;
+
+ ret = __remove_pages(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 630dd2c..bdd8a99 100644
--- a/arch/tile/mm/init.c
+++ b/arch/tile/mm/init.c
@@ -947,6 +947,14 @@ 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 575d86f..a690153 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -842,6 +842,16 @@ 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(unsigned long start, unsigned long size)
+{
+ unsigned long start_pfn = start >> PAGE_SHIFT;
+ unsigned long nr_pages = size >> PAGE_SHIFT;
+
+ return __remove_pages(start_pfn, nr_pages);
+}
+#endif
#endif
/*
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 9e635b3..78b94bc 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -675,6 +675,13 @@ int arch_add_memory(int nid, u64 start, u64 size)
}
EXPORT_SYMBOL_GPL(arch_add_memory);
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int arch_remove_memory(unsigned long start, unsigned long size)
+{
+ /* TODO */
+ return -EBUSY;
+}
+#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 2ba0a1a..8639799 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -84,6 +84,7 @@ 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(unsigned long start, unsigned long 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 dccdf71..cc2c8b9 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1055,7 +1055,7 @@ int __ref remove_memory(int nid, u64 start, u64 size)
unregister_one_node(nid);
}
- __remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT);
+ arch_remove_memory(start, size);
out:
unlock_memory_hotplug();
return ret;
--
1.7.1
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