| Message ID | 1358324059-9608-2-git-send-email-linfeng@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Wed 16-01-13 16:14:18, Lin Feng wrote: [...] > 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) I am still not sure I understand the relation to MEMORY_HOTREMOVE. Is register_page_bootmem_info_node required/helpful even if !CONFIG_MEMORY_HOTREMOVE? Also, now that I am thinking about that more, maybe it would be cleaner to put the select into arch/x86/Kconfig and do it same as ARCH_ENABLE_MEMORY_{HOTPLUG,HOTREMOVE} (and name it ARCH_HAVE_BOOTMEM_INFO_NODE).
Hi Michal, On 01/16/2013 10:14 PM, Michal Hocko wrote: > On Wed 16-01-13 16:14:18, Lin Feng wrote: > [...] >> 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) > > I am still not sure I understand the relation to MEMORY_HOTREMOVE. > Is register_page_bootmem_info_node required/helpful even if > !CONFIG_MEMORY_HOTREMOVE? From old kenrel's view register_page_bootmem_info_node() is defined in CONFIG_MEMORY_HOTPLUG_SPARSE, it registers some info for memory hotplug/remove. If we don't use MEMORY_HOTPLUG feature, this function is empty, we don't need the info at all. So this info is not required/helpful if !CONFIG_MEMORY_HOTREMOVE. > > Also, now that I am thinking about that more, maybe it would > be cleaner to put the select into arch/x86/Kconfig and do it > same as ARCH_ENABLE_MEMORY_{HOTPLUG,HOTREMOVE} (and name it > ARCH_HAVE_BOOTMEM_INFO_NODE). > Maybe put it in mm/Kconfig is a better choice, because if one day someone implements the register_page_bootmem_info_node() for other archs they will get some clues here, that's it has been implemented on x86_64. But I'm not so sure... thanks, linfeng
On Thu 17-01-13 18:37:10, Lin Feng wrote: [...] > > I am still not sure I understand the relation to MEMORY_HOTREMOVE. > > Is register_page_bootmem_info_node required/helpful even if > > !CONFIG_MEMORY_HOTREMOVE? > From old kenrel's view register_page_bootmem_info_node() is defined in > CONFIG_MEMORY_HOTPLUG_SPARSE, it registers some info for > memory hotplug/remove. If we don't use MEMORY_HOTPLUG feature, this > function is empty, we don't need the info at all. > So this info is not required/helpful if !CONFIG_MEMORY_HOTREMOVE. OK, then I suggest moving it under CONFIG_MEMORY_HOTREMOVE guards rather than CONFIG_MEMORY_HOTPLUG. > > Also, now that I am thinking about that more, maybe it would > > be cleaner to put the select into arch/x86/Kconfig and do it > > same as ARCH_ENABLE_MEMORY_{HOTPLUG,HOTREMOVE} (and name it > > ARCH_HAVE_BOOTMEM_INFO_NODE). > > > Maybe put it in mm/Kconfig is a better choice, because if one day > someone implements the register_page_bootmem_info_node() for other > archs they will get some clues here, that's it has been implemented on > x86_64. > But I'm not so sure... My understanding is that doing that in arch code is more appropriate because it makes the generic code less complicated. But I do not have any strong opinion on that. Looking at other ARCH_ENABLE_MEMORY_HOTPLUG and others suggests that we should be consistent with that. Thanks!
Hi Michal, On 01/17/2013 09:05 PM, Michal Hocko wrote: > On Thu 17-01-13 18:37:10, Lin Feng wrote: > [...] >>> > > I am still not sure I understand the relation to MEMORY_HOTREMOVE. >>> > > Is register_page_bootmem_info_node required/helpful even if >>> > > !CONFIG_MEMORY_HOTREMOVE? >> > From old kenrel's view register_page_bootmem_info_node() is defined in >> > CONFIG_MEMORY_HOTPLUG_SPARSE, it registers some info for >> > memory hotplug/remove. If we don't use MEMORY_HOTPLUG feature, this >> > function is empty, we don't need the info at all. >> > So this info is not required/helpful if !CONFIG_MEMORY_HOTREMOVE. > OK, then I suggest moving it under CONFIG_MEMORY_HOTREMOVE guards rather > than CONFIG_MEMORY_HOTPLUG. I can't agree more ;-) I also find that page_isolation.c selected by MEMORY_ISOLATION under MEMORY_HOTPLUG is also such case, I fix it by the way. thanks, linfeng >
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 07d6966..b539015 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..69903cc 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 inline 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); 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..daf111f 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 +231,7 @@ void register_page_bootmem_info_node(struct pglist_data *pgdat) register_page_bootmem_info_section(pfn); } } +#endif static void grow_zone_span(struct zone *zone, unsigned long start_pfn, unsigned long end_pfn)
It's implemented by adding a new Kconfig option named CONFIG_HAVE_BOOTMEM_INFO_NODE, which will be automatically selected by memory-hotplug feature fully supported archs(currently only on x86_64). Reported-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Lin Feng <linfeng@cn.fujitsu.com> --- ChangeLog v2->v3: - Rename the patch title to conform it's content. - Update memory_hotplug.h and remove the misleading TODO pointed out by Michal. 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). --- arch/x86/mm/init_64.c | 2 +- include/linux/memory_hotplug.h | 6 ++++++ mm/Kconfig | 8 ++++++++ mm/memory_hotplug.c | 2 ++ 4 files changed, 17 insertions(+), 1 deletions(-)