From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937127Ab3DJRmW (ORCPT ); Wed, 10 Apr 2013 13:42:22 -0400 Received: from g1t0029.austin.hp.com ([15.216.28.36]:34104 "EHLO g1t0029.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937080Ab3DJRmT (ORCPT ); Wed, 10 Apr 2013 13:42:19 -0400 Message-ID: <1365614999.32127.103.camel@misato.fc.hp.com> Subject: Re: [patch] mm, hotplug: avoid compiling memory hotremove functions when disabled From: Toshi Kani To: David Rientjes Cc: Andrew Morton , Benjamin Herrenschmidt , Paul Mackerras , Greg Kroah-Hartman , Wen Congyang , Tang Chen , Yasuaki Ishimatsu , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org Date: Wed, 10 Apr 2013 11:29:59 -0600 In-Reply-To: References: <1365440996-30981-1-git-send-email-toshi.kani@hp.com> <20130408134438.2a4388a07163e10a37158eed@linux-foundation.org> <1365454703.32127.8.camel@misato.fc.hp.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4 (3.6.4-3.fc18) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2013-04-09 at 23:07 -0700, David Rientjes wrote: > __remove_pages() is only necessary for CONFIG_MEMORY_HOTREMOVE. PowerPC > pseries will return -EOPNOTSUPP if unsupported. > > Adding an #ifdef causes several other functions it depends on to also > become unnecessary, which saves in .text when disabled (it's disabled in > most defconfigs besides powerpc, including x86). remove_memory_block() > becomes static since it is not referenced outside of > drivers/base/memory.c. > > Build tested on x86 and powerpc with CONFIG_MEMORY_HOTREMOVE both enabled > and disabled. > > Signed-off-by: David Rientjes Acked-by: Toshi Kani Thanks, -Toshi > --- > arch/powerpc/platforms/pseries/hotplug-memory.c | 12 +++++ > drivers/base/memory.c | 44 +++++++-------- > include/linux/memory.h | 3 +- > include/linux/memory_hotplug.h | 4 +- > mm/memory_hotplug.c | 68 +++++++++++------------ > mm/sparse.c | 72 +++++++++++++------------ > 6 files changed, 113 insertions(+), 90 deletions(-) > > diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c > --- a/arch/powerpc/platforms/pseries/hotplug-memory.c > +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c > @@ -72,6 +72,7 @@ unsigned long memory_block_size_bytes(void) > return get_memblock_size(); > } > > +#ifdef CONFIG_MEMORY_HOTREMOVE > static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size) > { > unsigned long start, start_pfn; > @@ -153,6 +154,17 @@ static int pseries_remove_memory(struct device_node *np) > ret = pseries_remove_memblock(base, lmb_size); > return ret; > } > +#else > +static inline int pseries_remove_memblock(unsigned long base, > + unsigned int memblock_size) > +{ > + return -EOPNOTSUPP; > +} > +static inline int pseries_remove_memory(struct device_node *np) > +{ > + return -EOPNOTSUPP; > +} > +#endif /* CONFIG_MEMORY_HOTREMOVE */ > > static int pseries_add_memory(struct device_node *np) > { > diff --git a/drivers/base/memory.c b/drivers/base/memory.c > --- a/drivers/base/memory.c > +++ b/drivers/base/memory.c > @@ -93,16 +93,6 @@ int register_memory(struct memory_block *memory) > return error; > } > > -static void > -unregister_memory(struct memory_block *memory) > -{ > - BUG_ON(memory->dev.bus != &memory_subsys); > - > - /* drop the ref. we got in remove_memory_block() */ > - kobject_put(&memory->dev.kobj); > - device_unregister(&memory->dev); > -} > - > unsigned long __weak memory_block_size_bytes(void) > { > return MIN_MEMORY_BLOCK_SIZE; > @@ -637,8 +627,28 @@ static int add_memory_section(int nid, struct mem_section *section, > return ret; > } > > -int remove_memory_block(unsigned long node_id, struct mem_section *section, > - int phys_device) > +/* > + * need an interface for the VM to add new memory regions, > + * but without onlining it. > + */ > +int register_new_memory(int nid, struct mem_section *section) > +{ > + return add_memory_section(nid, section, NULL, MEM_OFFLINE, HOTPLUG); > +} > + > +#ifdef CONFIG_MEMORY_HOTREMOVE > +static void > +unregister_memory(struct memory_block *memory) > +{ > + BUG_ON(memory->dev.bus != &memory_subsys); > + > + /* drop the ref. we got in remove_memory_block() */ > + kobject_put(&memory->dev.kobj); > + device_unregister(&memory->dev); > +} > + > +static int remove_memory_block(unsigned long node_id, > + struct mem_section *section, int phys_device) > { > struct memory_block *mem; > > @@ -661,15 +671,6 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section, > return 0; > } > > -/* > - * need an interface for the VM to add new memory regions, > - * but without onlining it. > - */ > -int register_new_memory(int nid, struct mem_section *section) > -{ > - return add_memory_section(nid, section, NULL, MEM_OFFLINE, HOTPLUG); > -} > - > int unregister_memory_section(struct mem_section *section) > { > if (!present_section(section)) > @@ -677,6 +678,7 @@ int unregister_memory_section(struct mem_section *section) > > return remove_memory_block(0, section, 0); > } > +#endif /* CONFIG_MEMORY_HOTREMOVE */ > > /* > * offline one memory block. If the memory block has been offlined, do nothing. > diff --git a/include/linux/memory.h b/include/linux/memory.h > --- a/include/linux/memory.h > +++ b/include/linux/memory.h > @@ -114,9 +114,10 @@ extern void unregister_memory_notifier(struct notifier_block *nb); > extern int register_memory_isolate_notifier(struct notifier_block *nb); > extern void unregister_memory_isolate_notifier(struct notifier_block *nb); > extern int register_new_memory(int, struct mem_section *); > +#ifdef CONFIG_MEMORY_HOTREMOVE > extern int unregister_memory_section(struct mem_section *); > +#endif > extern int memory_dev_init(void); > -extern int remove_memory_block(unsigned long, struct mem_section *, int); > extern int memory_notify(unsigned long val, void *v); > extern int memory_isolate_notify(unsigned long val, void *v); > extern struct memory_block *find_memory_block_hinted(struct mem_section *, > diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h > --- a/include/linux/memory_hotplug.h > +++ b/include/linux/memory_hotplug.h > @@ -97,13 +97,13 @@ 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); > +extern int __remove_pages(struct zone *zone, unsigned long start_pfn, > + unsigned long nr_pages); > #endif /* CONFIG_MEMORY_HOTREMOVE */ > > /* reasonably generic interface to expand the physical pages in a zone */ > extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn, > unsigned long nr_pages); > -extern int __remove_pages(struct zone *zone, unsigned long start_pfn, > - unsigned long nr_pages); > > #ifdef CONFIG_NUMA > extern int memory_add_physaddr_to_nid(u64 start); > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -436,6 +436,40 @@ static int __meminit __add_section(int nid, struct zone *zone, > return register_new_memory(nid, __pfn_to_section(phys_start_pfn)); > } > > +/* > + * Reasonably generic function for adding memory. It is > + * expected that archs that support memory hotplug will > + * call this function after deciding the zone to which to > + * add the new pages. > + */ > +int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn, > + unsigned long nr_pages) > +{ > + unsigned long i; > + int err = 0; > + int start_sec, end_sec; > + /* during initialize mem_map, align hot-added range to section */ > + start_sec = pfn_to_section_nr(phys_start_pfn); > + end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); > + > + for (i = start_sec; i <= end_sec; i++) { > + err = __add_section(nid, zone, i << PFN_SECTION_SHIFT); > + > + /* > + * EEXIST is finally dealt with by ioresource collision > + * check. see add_memory() => register_memory_resource() > + * Warning will be printed if there is collision. > + */ > + if (err && (err != -EEXIST)) > + break; > + err = 0; > + } > + > + return err; > +} > +EXPORT_SYMBOL_GPL(__add_pages); > + > +#ifdef CONFIG_MEMORY_HOTREMOVE > /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ > static int find_smallest_section_pfn(int nid, struct zone *zone, > unsigned long start_pfn, > @@ -658,39 +692,6 @@ static int __remove_section(struct zone *zone, struct mem_section *ms) > return 0; > } > > -/* > - * Reasonably generic function for adding memory. It is > - * expected that archs that support memory hotplug will > - * call this function after deciding the zone to which to > - * add the new pages. > - */ > -int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn, > - unsigned long nr_pages) > -{ > - unsigned long i; > - int err = 0; > - int start_sec, end_sec; > - /* during initialize mem_map, align hot-added range to section */ > - start_sec = pfn_to_section_nr(phys_start_pfn); > - end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); > - > - for (i = start_sec; i <= end_sec; i++) { > - err = __add_section(nid, zone, i << PFN_SECTION_SHIFT); > - > - /* > - * EEXIST is finally dealt with by ioresource collision > - * check. see add_memory() => register_memory_resource() > - * Warning will be printed if there is collision. > - */ > - if (err && (err != -EEXIST)) > - break; > - err = 0; > - } > - > - return err; > -} > -EXPORT_SYMBOL_GPL(__add_pages); > - > /** > * __remove_pages() - remove sections of pages from a zone > * @zone: zone from which pages need to be removed > @@ -726,6 +727,7 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, > return ret; > } > EXPORT_SYMBOL_GPL(__remove_pages); > +#endif /* CONFIG_MEMORY_HOTREMOVE */ > > int set_online_page_callback(online_page_callback_t callback) > { > diff --git a/mm/sparse.c b/mm/sparse.c > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -620,6 +620,7 @@ static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages) > > vmemmap_free(start, end); > } > +#ifdef CONFIG_MEMORY_HOTREMOVE > static void free_map_bootmem(struct page *memmap, unsigned long nr_pages) > { > unsigned long start = (unsigned long)memmap; > @@ -627,6 +628,7 @@ static void free_map_bootmem(struct page *memmap, unsigned long nr_pages) > > vmemmap_free(start, end); > } > +#endif /* CONFIG_MEMORY_HOTREMOVE */ > #else > static struct page *__kmalloc_section_memmap(unsigned long nr_pages) > { > @@ -664,6 +666,7 @@ static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages) > get_order(sizeof(struct page) * nr_pages)); > } > > +#ifdef CONFIG_MEMORY_HOTREMOVE > static void free_map_bootmem(struct page *memmap, unsigned long nr_pages) > { > unsigned long maps_section_nr, removing_section_nr, i; > @@ -690,40 +693,9 @@ static void free_map_bootmem(struct page *memmap, unsigned long nr_pages) > put_page_bootmem(page); > } > } > +#endif /* CONFIG_MEMORY_HOTREMOVE */ > #endif /* CONFIG_SPARSEMEM_VMEMMAP */ > > -static void free_section_usemap(struct page *memmap, unsigned long *usemap) > -{ > - struct page *usemap_page; > - unsigned long nr_pages; > - > - if (!usemap) > - return; > - > - usemap_page = virt_to_page(usemap); > - /* > - * Check to see if allocation came from hot-plug-add > - */ > - if (PageSlab(usemap_page) || PageCompound(usemap_page)) { > - kfree(usemap); > - if (memmap) > - __kfree_section_memmap(memmap, PAGES_PER_SECTION); > - return; > - } > - > - /* > - * The usemap came from bootmem. This is packed with other usemaps > - * on the section which has pgdat at boot time. Just keep it as is now. > - */ > - > - if (memmap) { > - nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) > - >> PAGE_SHIFT; > - > - free_map_bootmem(memmap, nr_pages); > - } > -} > - > /* > * returns the number of sections whose mem_maps were properly > * set. If this is <=0, then that means that the passed-in > @@ -800,6 +772,39 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) > } > #endif > > +#ifdef CONFIG_MEMORY_HOTREMOVE > +static void free_section_usemap(struct page *memmap, unsigned long *usemap) > +{ > + struct page *usemap_page; > + unsigned long nr_pages; > + > + if (!usemap) > + return; > + > + usemap_page = virt_to_page(usemap); > + /* > + * Check to see if allocation came from hot-plug-add > + */ > + if (PageSlab(usemap_page) || PageCompound(usemap_page)) { > + kfree(usemap); > + if (memmap) > + __kfree_section_memmap(memmap, PAGES_PER_SECTION); > + return; > + } > + > + /* > + * The usemap came from bootmem. This is packed with other usemaps > + * on the section which has pgdat at boot time. Just keep it as is now. > + */ > + > + if (memmap) { > + nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) > + >> PAGE_SHIFT; > + > + free_map_bootmem(memmap, nr_pages); > + } > +} > + > void sparse_remove_one_section(struct zone *zone, struct mem_section *ms) > { > struct page *memmap = NULL; > @@ -819,4 +824,5 @@ void sparse_remove_one_section(struct zone *zone, struct mem_section *ms) > clear_hwpoisoned_pages(memmap, PAGES_PER_SECTION); > free_section_usemap(memmap, usemap); > } > -#endif > +#endif /* CONFIG_MEMORY_HOTREMOVE */ > +#endif /* CONFIG_MEMORY_HOTPLUG */