[PATCH v6 05/15] memory-hotplug: introduce new function arch_remove_memory() for removing page table
From: Tang Chen <hidden>
Date: 2013-01-09 09:33:45
Also in:
linux-acpi, linux-mm, linux-s390, linux-sh, linuxppc-dev, 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
From: Wen Congyang <redacted>
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).
Signed-off-by: Wen Congyang <redacted>
Acked-by: KAMEZAWA Hiroyuki <redacted>
---
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(+), 0 deletions(-)
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index b755ea9..20bc967 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c@@ -688,6 +688,24 @@ 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 ae672f4..49ce6bb 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c@@ -228,4 +228,16 @@ 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 745d66b..3166e78 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c@@ -836,6 +836,18 @@ 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 e779e0b..f78509c 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c@@ -682,6 +682,21 @@ 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 8dd0950..31a563b 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h@@ -96,6 +96,7 @@ 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 9fd5904..f6724c2 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c@@ -1514,6 +1514,8 @@ repeat: /* remove memmap entry */ firmware_map_remove(start, start + size, "System RAM"); + arch_remove_memory(start, size); + unlock_memory_hotplug(); return 0;
--
1.7.1