[RFC PATCH 6/8] memory-hotplug: introduce new function arch_remove_memory()
Yasuaki Ishimatsu
isimatu.yasuaki at jp.fujitsu.com
Fri Jul 20 18:21:51 EST 2012
2012/07/20 16:12, Wen Congyang wrote:
> 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.
I think you need cc to other arch ML for reviewing the patch.
> CC: David Rientjes <rientjes at google.com>
> CC: Jiang Liu <liuj97 at gmail.com>
> CC: Len Brown <len.brown at intel.com>
> CC: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> CC: Paul Mackerras <paulus at samba.org>
> CC: Christoph Lameter <cl at linux.com>
> Cc: Minchan Kim <minchan.kim at gmail.com>
> CC: Andrew Morton <akpm at linux-foundation.org>
> CC: KOSAKI Motohiro <kosaki.motohiro at jp.fujitsu.com>
> CC: Yasuaki Ishimatsu <isimatu.yasuaki at jp.fujitsu.com>
> Signed-off-by: Wen Congyang <wency at cn.fujitsu.com>
> ---
> 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
Why does not the function call __remove_pages()?
Thanks,
Yasuaki ishimatsu
> #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;
>
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