From: Michal Hocko <mhocko@xxxxxxxx> Subject: mm/memory_hotplug: introduce add_pages There are new users of memory hotplug emerging. Some of them require different subset of arch_add_memory. There are some which only require allocation of struct pages without mapping those pages to the kernel address space. We currently have __add_pages for that purpose. But this is rather lowlevel and not very suitable for the code outside of the memory hotplug. E.g. x86_64 wants to update max_pfn which should be done by the caller. Introduce add_pages() which should care about those details if they are needed. Each architecture should define its implementation and select CONFIG_ARCH_HAS_ADD_PAGES. All others use the currently existing __add_pages. Link: http://lkml.kernel.org/r/20170817000548.32038-7-jglisse@xxxxxxxxxx Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Signed-off-by: Jérôme Glisse <jglisse@xxxxxxxxxx> Acked-by: Balbir Singh <bsingharora@xxxxxxxxx> Cc: Aneesh Kumar <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: David Nellans <dnellans@xxxxxxxxxx> Cc: Evgeny Baskakov <ebaskakov@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: John Hubbard <jhubbard@xxxxxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Mark Hairgrove <mhairgrove@xxxxxxxxxx> Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Cc: Sherry Cheung <SCheung@xxxxxxxxxx> Cc: Subhash Gutti <sgutti@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Bob Liu <liubo95@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/Kconfig | 4 ++++ arch/x86/mm/init_64.c | 22 +++++++++++++++------- include/linux/memory_hotplug.h | 11 +++++++++++ 3 files changed, 30 insertions(+), 7 deletions(-) diff -puN arch/x86/Kconfig~mm-memory_hotplug-introduce-add_pages arch/x86/Kconfig --- a/arch/x86/Kconfig~mm-memory_hotplug-introduce-add_pages +++ a/arch/x86/Kconfig @@ -2323,6 +2323,10 @@ source "kernel/livepatch/Kconfig" endmenu +config ARCH_HAS_ADD_PAGES + def_bool y + depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG + config ARCH_ENABLE_MEMORY_HOTPLUG def_bool y depends on X86_64 || (X86_32 && HIGHMEM) diff -puN arch/x86/mm/init_64.c~mm-memory_hotplug-introduce-add_pages arch/x86/mm/init_64.c --- a/arch/x86/mm/init_64.c~mm-memory_hotplug-introduce-add_pages +++ a/arch/x86/mm/init_64.c @@ -761,7 +761,7 @@ void __init paging_init(void) * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need * updating. */ -static void update_end_of_memory_vars(u64 start, u64 size) +static void update_end_of_memory_vars(u64 start, u64 size) { unsigned long end_pfn = PFN_UP(start + size); @@ -772,22 +772,30 @@ static void update_end_of_memory_vars(u } } -int arch_add_memory(int nid, u64 start, u64 size, bool want_memblock) +int add_pages(int nid, unsigned long start_pfn, + unsigned long nr_pages, bool want_memblock) { - unsigned long start_pfn = start >> PAGE_SHIFT; - unsigned long nr_pages = size >> PAGE_SHIFT; int ret; - init_memory_mapping(start, start + size); - ret = __add_pages(nid, start_pfn, nr_pages, want_memblock); WARN_ON_ONCE(ret); /* update max_pfn, max_low_pfn and high_memory */ - update_end_of_memory_vars(start, size); + update_end_of_memory_vars(start_pfn << PAGE_SHIFT, + nr_pages << PAGE_SHIFT); return ret; } + +int arch_add_memory(int nid, u64 start, u64 size, bool want_memblock) +{ + unsigned long start_pfn = start >> PAGE_SHIFT; + unsigned long nr_pages = size >> PAGE_SHIFT; + + init_memory_mapping(start, start + size); + + return add_pages(nid, start_pfn, nr_pages, want_memblock); +} EXPORT_SYMBOL_GPL(arch_add_memory); #define PAGE_INUSE 0xFD diff -puN include/linux/memory_hotplug.h~mm-memory_hotplug-introduce-add_pages include/linux/memory_hotplug.h --- a/include/linux/memory_hotplug.h~mm-memory_hotplug-introduce-add_pages +++ a/include/linux/memory_hotplug.h @@ -133,6 +133,17 @@ extern int __remove_pages(struct zone *z extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages, bool want_memblock); +#ifndef CONFIG_ARCH_HAS_ADD_PAGES +static inline int add_pages(int nid, unsigned long start_pfn, + unsigned long nr_pages, bool want_memblock) +{ + return __add_pages(nid, start_pfn, nr_pages, want_memblock); +} +#else /* ARCH_HAS_ADD_PAGES */ +int add_pages(int nid, unsigned long start_pfn, + unsigned long nr_pages, bool want_memblock); +#endif /* ARCH_HAS_ADD_PAGES */ + #ifdef CONFIG_NUMA extern int memory_add_physaddr_to_nid(u64 start); #else _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
