mm, hotplug: avoid compiling memory hotremove functions when disabled

__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 <rientjes@google.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, hotplug: avoid compiling memory hotremove functions when disabled
__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 <rientjes@google.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes · Linus Torvalds
1 parent fe74ebb106
Showing 6 changed files with 113 additions and 90 deletions Side-by-side Diff
arch/powerpc/platforms/pseries/hotplug-memory.c
drivers/base/memory.c
include/linux/memory.h
include/linux/memory_hotplug.h
mm/memory_hotplug.c
mm/sparse.c
@@ -72,6 +72,7 @@
 	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 @@
 	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)
 {
@@ -93,16 +93,6 @@
 	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;
  
@@ -637,9 +627,29 @@
 	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;
  
 	mutex_lock(&mem_sysfs_mutex);
@@ -661,15 +671,6 @@
 	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 @@
  
 	return remove_memory_block(0, section, 0);
 }
+#endif /* CONFIG_MEMORY_HOTREMOVE */
  
 /*
  * offline one memory block. If the memory block has been offlined, do nothing.
@@ -115,9 +115,10 @@
 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 *,
@@ -97,12 +97,12 @@
 #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
@@ -436,6 +436,40 @@
 	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 @@
 	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
@@ -733,6 +734,7 @@
 	return ret;
 }
 EXPORT_SYMBOL_GPL(__remove_pages);
+#endif /* CONFIG_MEMORY_HOTREMOVE */
  
 int set_online_page_callback(online_page_callback_t callback)
 {
@@ -620,6 +620,7 @@
  
 	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 @@
  
 	vmemmap_free(start, end);
 }
+#endif /* CONFIG_MEMORY_HOTREMOVE */
 #else
 static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
 {
@@ -664,6 +666,7 @@
 			   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 @@
 			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 @@
 }
 #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;
@@ -819,5 +824,6 @@
 	clear_hwpoisoned_pages(memmap, PAGES_PER_SECTION);
 	free_section_usemap(memmap, usemap);
 }
-#endif
+#endif /* CONFIG_MEMORY_HOTREMOVE */
+#endif /* CONFIG_MEMORY_HOTPLUG */
...	...	@@ -72,6 +72,7 @@
72	72	return get_memblock_size();
73	73	}
74	74
	75	+#ifdef CONFIG_MEMORY_HOTREMOVE
75	76	static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
76	77	{
77	78	unsigned long start, start_pfn;
...	...	@@ -153,6 +154,17 @@
153	154	ret = pseries_remove_memblock(base, lmb_size);
154	155	return ret;
155	156	}
	157	+#else
	158	+static inline int pseries_remove_memblock(unsigned long base,
	159	+ unsigned int memblock_size)
	160	+{
	161	+ return -EOPNOTSUPP;
	162	+}
	163	+static inline int pseries_remove_memory(struct device_node *np)
	164	+{
	165	+ return -EOPNOTSUPP;
	166	+}
	167	+#endif /* CONFIG_MEMORY_HOTREMOVE */
156	168
157	169	static int pseries_add_memory(struct device_node *np)
158	170	{
...	...	@@ -93,16 +93,6 @@
93	93	return error;
94	94	}
95	95
96		-static void
97		-unregister_memory(struct memory_block *memory)
98		-{
99		- BUG_ON(memory->dev.bus != &memory_subsys);
100		-
101		- /* drop the ref. we got in remove_memory_block() */
102		- kobject_put(&memory->dev.kobj);
103		- device_unregister(&memory->dev);
104		-}
105		-
106	96	unsigned long __weak memory_block_size_bytes(void)
107	97	{
108	98	return MIN_MEMORY_BLOCK_SIZE;
109	99
...	...	@@ -637,9 +627,29 @@
637	627	return ret;
638	628	}
639	629
640		-int remove_memory_block(unsigned long node_id, struct mem_section *section,
641		- int phys_device)
	630	+/*
	631	+ * need an interface for the VM to add new memory regions,
	632	+ * but without onlining it.
	633	+ */
	634	+int register_new_memory(int nid, struct mem_section *section)
642	635	{
	636	+ return add_memory_section(nid, section, NULL, MEM_OFFLINE, HOTPLUG);
	637	+}
	638	+
	639	+#ifdef CONFIG_MEMORY_HOTREMOVE
	640	+static void
	641	+unregister_memory(struct memory_block *memory)
	642	+{
	643	+ BUG_ON(memory->dev.bus != &memory_subsys);
	644	+
	645	+ /* drop the ref. we got in remove_memory_block() */
	646	+ kobject_put(&memory->dev.kobj);
	647	+ device_unregister(&memory->dev);
	648	+}
	649	+
	650	+static int remove_memory_block(unsigned long node_id,
	651	+ struct mem_section *section, int phys_device)
	652	+{
643	653	struct memory_block *mem;
644	654
645	655	mutex_lock(&mem_sysfs_mutex);
...	...	@@ -661,15 +671,6 @@
661	671	return 0;
662	672	}
663	673
664		-/*
665		- * need an interface for the VM to add new memory regions,
666		- * but without onlining it.
667		- */
668		-int register_new_memory(int nid, struct mem_section *section)
669		-{
670		- return add_memory_section(nid, section, NULL, MEM_OFFLINE, HOTPLUG);
671		-}
672		-
673	674	int unregister_memory_section(struct mem_section *section)
674	675	{
675	676	if (!present_section(section))
...	...	@@ -677,6 +678,7 @@
677	678
678	679	return remove_memory_block(0, section, 0);
679	680	}
	681	+#endif /* CONFIG_MEMORY_HOTREMOVE */
680	682
681	683	/*
682	684	* offline one memory block. If the memory block has been offlined, do nothing.
...	...	@@ -115,9 +115,10 @@
115	115	extern int register_memory_isolate_notifier(struct notifier_block *nb);
116	116	extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
117	117	extern int register_new_memory(int, struct mem_section *);
	118	+#ifdef CONFIG_MEMORY_HOTREMOVE
118	119	extern int unregister_memory_section(struct mem_section *);
	120	+#endif
119	121	extern int memory_dev_init(void);
120		-extern int remove_memory_block(unsigned long, struct mem_section *, int);
121	122	extern int memory_notify(unsigned long val, void *v);
122	123	extern int memory_isolate_notify(unsigned long val, void *v);
123	124	extern struct memory_block find_memory_block_hinted(struct mem_section ,
...	...	@@ -97,12 +97,12 @@
97	97	#ifdef CONFIG_MEMORY_HOTREMOVE
98	98	extern bool is_pageblock_removable_nolock(struct page *page);
99	99	extern int arch_remove_memory(u64 start, u64 size);
	100	+extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
	101	+ unsigned long nr_pages);
100	102	#endif /* CONFIG_MEMORY_HOTREMOVE */
101	103
102	104	/* reasonably generic interface to expand the physical pages in a zone */
103	105	extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn,
104		- unsigned long nr_pages);
105		-extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
106	106	unsigned long nr_pages);
107	107
108	108	#ifdef CONFIG_NUMA
...	...	@@ -436,6 +436,40 @@
436	436	return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
437	437	}
438	438
	439	+/*
	440	+ * Reasonably generic function for adding memory. It is
	441	+ * expected that archs that support memory hotplug will
	442	+ * call this function after deciding the zone to which to
	443	+ * add the new pages.
	444	+ */
	445	+int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
	446	+ unsigned long nr_pages)
	447	+{
	448	+ unsigned long i;
	449	+ int err = 0;
	450	+ int start_sec, end_sec;
	451	+ /* during initialize mem_map, align hot-added range to section */
	452	+ start_sec = pfn_to_section_nr(phys_start_pfn);
	453	+ end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
	454	+
	455	+ for (i = start_sec; i <= end_sec; i++) {
	456	+ err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
	457	+
	458	+ /*
	459	+ * EEXIST is finally dealt with by ioresource collision
	460	+ * check. see add_memory() => register_memory_resource()
	461	+ * Warning will be printed if there is collision.
	462	+ */
	463	+ if (err && (err != -EEXIST))
	464	+ break;
	465	+ err = 0;
	466	+ }
	467	+
	468	+ return err;
	469	+}
	470	+EXPORT_SYMBOL_GPL(__add_pages);
	471	+
	472	+#ifdef CONFIG_MEMORY_HOTREMOVE
439	473	/* find the smallest valid pfn in the range [start_pfn, end_pfn) */
440	474	static int find_smallest_section_pfn(int nid, struct zone *zone,
441	475	unsigned long start_pfn,
...	...	@@ -658,39 +692,6 @@
658	692	return 0;
659	693	}
660	694
661		-/*
662		- * Reasonably generic function for adding memory. It is
663		- * expected that archs that support memory hotplug will
664		- * call this function after deciding the zone to which to
665		- * add the new pages.
666		- */
667		-int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
668		- unsigned long nr_pages)
669		-{
670		- unsigned long i;
671		- int err = 0;
672		- int start_sec, end_sec;
673		- /* during initialize mem_map, align hot-added range to section */
674		- start_sec = pfn_to_section_nr(phys_start_pfn);
675		- end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
676		-
677		- for (i = start_sec; i <= end_sec; i++) {
678		- err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
679		-
680		- /*
681		- * EEXIST is finally dealt with by ioresource collision
682		- * check. see add_memory() => register_memory_resource()
683		- * Warning will be printed if there is collision.
684		- */
685		- if (err && (err != -EEXIST))
686		- break;
687		- err = 0;
688		- }
689		-
690		- return err;
691		-}
692		-EXPORT_SYMBOL_GPL(__add_pages);
693		-
694	695	/**
695	696	* __remove_pages() - remove sections of pages from a zone
696	697	* @zone: zone from which pages need to be removed
...	...	@@ -733,6 +734,7 @@
733	734	return ret;
734	735	}
735	736	EXPORT_SYMBOL_GPL(__remove_pages);
	737	+#endif /* CONFIG_MEMORY_HOTREMOVE */
736	738
737	739	int set_online_page_callback(online_page_callback_t callback)
738	740	{
...	...	@@ -620,6 +620,7 @@
620	620
621	621	vmemmap_free(start, end);
622	622	}
	623	+#ifdef CONFIG_MEMORY_HOTREMOVE
623	624	static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
624	625	{
625	626	unsigned long start = (unsigned long)memmap;
...	...	@@ -627,6 +628,7 @@
627	628
628	629	vmemmap_free(start, end);
629	630	}
	631	+#endif /* CONFIG_MEMORY_HOTREMOVE */
630	632	#else
631	633	static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
632	634	{
...	...	@@ -664,6 +666,7 @@
664	666	get_order(sizeof(struct page) * nr_pages));
665	667	}
666	668
	669	+#ifdef CONFIG_MEMORY_HOTREMOVE
667	670	static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
668	671	{
669	672	unsigned long maps_section_nr, removing_section_nr, i;
670	673
...	...	@@ -690,40 +693,9 @@
690	693	put_page_bootmem(page);
691	694	}
692	695	}
	696	+#endif /* CONFIG_MEMORY_HOTREMOVE */
693	697	#endif /* CONFIG_SPARSEMEM_VMEMMAP */
694	698
695		-static void free_section_usemap(struct page memmap, unsigned long usemap)
696		-{
697		- struct page *usemap_page;
698		- unsigned long nr_pages;
699		-
700		- if (!usemap)
701		- return;
702		-
703		- usemap_page = virt_to_page(usemap);
704		- /*
705		- * Check to see if allocation came from hot-plug-add
706		- */
707		- if (PageSlab(usemap_page) \|\| PageCompound(usemap_page)) {
708		- kfree(usemap);
709		- if (memmap)
710		- __kfree_section_memmap(memmap, PAGES_PER_SECTION);
711		- return;
712		- }
713		-
714		- /*
715		- * The usemap came from bootmem. This is packed with other usemaps
716		- * on the section which has pgdat at boot time. Just keep it as is now.
717		- */
718		-
719		- if (memmap) {
720		- nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
721		- >> PAGE_SHIFT;
722		-
723		- free_map_bootmem(memmap, nr_pages);
724		- }
725		-}
726		-
727	699	/*
728	700	* returns the number of sections whose mem_maps were properly
729	701	* set. If this is <=0, then that means that the passed-in
...	...	@@ -800,6 +772,39 @@
800	772	}
801	773	#endif
802	774
	775	+#ifdef CONFIG_MEMORY_HOTREMOVE
	776	+static void free_section_usemap(struct page memmap, unsigned long usemap)
	777	+{
	778	+ struct page *usemap_page;
	779	+ unsigned long nr_pages;
	780	+
	781	+ if (!usemap)
	782	+ return;
	783	+
	784	+ usemap_page = virt_to_page(usemap);
	785	+ /*
	786	+ * Check to see if allocation came from hot-plug-add
	787	+ */
	788	+ if (PageSlab(usemap_page) \|\| PageCompound(usemap_page)) {
	789	+ kfree(usemap);
	790	+ if (memmap)
	791	+ __kfree_section_memmap(memmap, PAGES_PER_SECTION);
	792	+ return;
	793	+ }
	794	+
	795	+ /*
	796	+ * The usemap came from bootmem. This is packed with other usemaps
	797	+ * on the section which has pgdat at boot time. Just keep it as is now.
	798	+ */
	799	+
	800	+ if (memmap) {
	801	+ nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
	802	+ >> PAGE_SHIFT;
	803	+
	804	+ free_map_bootmem(memmap, nr_pages);
	805	+ }
	806	+}
	807	+
803	808	void sparse_remove_one_section(struct zone zone, struct mem_section ms)
804	809	{
805	810	struct page *memmap = NULL;
...	...	@@ -819,5 +824,6 @@
819	824	clear_hwpoisoned_pages(memmap, PAGES_PER_SECTION);
820	825	free_section_usemap(memmap, usemap);
821	826	}
822		-#endif
	827	+#endif /* CONFIG_MEMORY_HOTREMOVE */
	828	+#endif /* CONFIG_MEMORY_HOTPLUG */