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>
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index c916582..60f6daa 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -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)
{