[RFC PATCH 6/8] memory-hotplug: introduce new function arch_remove_memory()
From: Wen Congyang <hidden>
Date: 2012-07-20 07:07:41
Also in:
linux-acpi, linux-mm, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), memory hot(un)plug, memory management, s390 architecture, superh, the rest, x86 architecture (32-bit and 64-bit), x86 mm · Maintainers:
Madhavan Srinivasan, Michael Ellerman, David Hildenbrand, Oscar Salvador, Andrew Morton, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
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@google.com> CC: Jiang Liu <redacted> CC: Len Brown <redacted> CC: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <redacted> CC: Christoph Lameter <redacted> Cc: Minchan Kim <redacted> CC: Andrew Morton <akpm@linux-foundation.org> CC: KOSAKI Motohiro <redacted> CC: Yasuaki Ishimatsu <redacted> Signed-off-by: Wen Congyang <redacted> --- 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