On Tue 15-01-13 18:20:03, Lin Feng wrote: > Memory-hotplug codes for x86_64 have been implemented by patchset: > https://lkml.org/lkml/2013/1/9/124 > While other platforms haven't been completely implemented yet. > > If we enable both CONFIG_MEMORY_HOTPLUG_SPARSE and CONFIG_SPARSEMEM_VMEMMAP, > register_page_bootmem_info_node() may be buggy, which is a hotplug generic > function but falling back to call platform related function > register_page_bootmem_memmap(). > > Other platforms such as powerpc it's not implemented, so on such platforms, > revert them to empty as they were before. > > It's implemented by adding a new Kconfig option named > CONFIG_HAVE_BOOTMEM_INFO_NODE, which will be automatically selected by > supported archs(currently only on x86_64). > > Reported-by: Michal Hocko <mhocko@xxxxxxx> > Signed-off-by: Lin Feng <linfeng@xxxxxxxxxxxxxx> > --- > ChangeLog v1->v2: > - Add a Kconfig option named HAVE_BOOTMEM_INFO_NODE suggested by Michal, which > will be automatically selected by supported archs(currently only on x86_64). > --- > mm/Kconfig | 8 ++++++++ > mm/memory_hotplug.c | 7 +++++++ > 2 files changed, 15 insertions(+), 0 deletions(-) > > diff --git a/mm/Kconfig b/mm/Kconfig > index 278e3ab..f8c5799 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -162,10 +162,18 @@ config MOVABLE_NODE > Say Y here if you want to hotplug a whole node. > Say N here if you want kernel to use memory on all nodes evenly. > > +# > +# Only be set on architectures that have completely implemented memory hotplug > +# feature. If you are not sure, don't touch it. > +# > +config HAVE_BOOTMEM_INFO_NODE > + def_bool n > + > # eventually, we can have this option just 'select SPARSEMEM' > config MEMORY_HOTPLUG > bool "Allow for memory hot-add" > select MEMORY_ISOLATION > + select HAVE_BOOTMEM_INFO_NODE if X86_64 > depends on SPARSEMEM || X86_64_ACPI_NUMA > depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG > depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390) > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 8aa2b56..ef7a5c8 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -189,6 +189,7 @@ static void register_page_bootmem_info_section(unsigned long start_pfn) > } > #endif > > +#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE > void register_page_bootmem_info_node(struct pglist_data *pgdat) > { > unsigned long i, pfn, end_pfn, nr_pages; > @@ -230,6 +231,12 @@ void register_page_bootmem_info_node(struct pglist_data *pgdat) > register_page_bootmem_info_section(pfn); > } > } > +#else > +void register_page_bootmem_info_node(struct pglist_data *pgdat) > +{ > + /* TODO */ > +} I think that TODO is misleading here because the function should be empty if !CONFIG_HAVE_BOOTMEM_INFO_NODE. I would also suggest updating include/linux/memory_hotplug.h and removing the arch specific functions without any implementation. Something like (untested) patch below: --- diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c index 882a0fd..cb5e1ff 100644 --- a/arch/ia64/mm/discontig.c +++ b/arch/ia64/mm/discontig.c @@ -827,9 +827,4 @@ void vmemmap_free(struct page *memmap, unsigned long nr_pages) { } -void register_page_bootmem_memmap(unsigned long section_nr, - struct page *start_page, unsigned long size) -{ - /* TODO */ -} #endif diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c index 2969591..7e2246f 100644 --- a/arch/powerpc/mm/init_64.c +++ b/arch/powerpc/mm/init_64.c @@ -302,10 +302,5 @@ void vmemmap_free(struct page *memmap, unsigned long nr_pages) { } -void register_page_bootmem_memmap(unsigned long section_nr, - struct page *start_page, unsigned long size) -{ - /* TODO */ -} #endif /* CONFIG_SPARSEMEM_VMEMMAP */ diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index 4073156..139bb48 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -240,12 +240,6 @@ void vmemmap_free(struct page *memmap, unsigned long nr_pages) { } -void register_page_bootmem_memmap(unsigned long section_nr, - struct page *start_page, unsigned long size) -{ - /* TODO */ -} - /* * Add memory segment to the segment list if it doesn't overlap with * an already present segment. diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index f0ef3c2..07571a27 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -2236,11 +2236,6 @@ void vmemmap_free(struct page *memmap, unsigned long nr_pages) { } -void register_page_bootmem_memmap(unsigned long section_nr, - struct page *start_page, unsigned long size) -{ - /* TODO */ -} #endif /* CONFIG_SPARSEMEM_VMEMMAP */ static void prot_init_common(unsigned long page_none, diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index d1b8257..defe6ee 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1317,7 +1317,7 @@ vmemmap_populate(struct page *start_page, unsigned long size, int node) return 0; } -#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE +#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE) void register_page_bootmem_memmap(unsigned long section_nr, struct page *start_page, unsigned long size) { diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index f60e728..34b0511 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -174,7 +174,13 @@ static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat) #endif /* CONFIG_NUMA */ #endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */ +#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE extern void register_page_bootmem_info_node(struct pglist_data *pgdat); +#else +static void register_page_bootmem_info_node(struct pglist_data *pgdat) +{ +} +#endif extern void put_page_bootmem(struct page *page); extern void get_page_bootmem(unsigned long ingo, struct page *page, unsigned long type); -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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