1 files changed, 11 insertions, 70 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 1ad92b46753e..081b4d654ed6 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1621,6 +1621,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
 {
         return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ);
 }
+#endif /* CONFIG_MEMORY_HOTREMOVE */
 
 /**
  * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
@@ -1634,7 +1635,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
  *
  * Returns the return value of func.
  */
-static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
+int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
                 void *arg, int (*func)(struct memory_block *, void *))
 {
         struct memory_block *mem = NULL;
@@ -1671,24 +1672,7 @@ static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
         return 0;
 }
 
-/**
- * offline_memory_block_cb - callback function for offlining memory block
- * @mem: the memory block to be offlined
- * @arg: buffer to hold error msg
- *
- * Always return 0, and put the error msg in arg if any.
- */
-static int offline_memory_block_cb(struct memory_block *mem, void *arg)
-{
-        int *ret = arg;
-        int error = offline_memory_block(mem);
-
-        if (error != 0 && *ret == 0)
-                *ret = error;
-
-        return 0;
-}
-
+#ifdef CONFIG_MEMORY_HOTREMOVE
 static int is_memblock_offlined_cb(struct memory_block *mem, void *arg)
 {
         int ret = !is_memblock_offlined(mem);
@@ -1814,54 +1798,22 @@ void try_offline_node(int nid)
 }
 EXPORT_SYMBOL(try_offline_node);
 
-int __ref remove_memory(int nid, u64 start, u64 size)
+void __ref remove_memory(int nid, u64 start, u64 size)
 {
-        unsigned long start_pfn, end_pfn;
-        int ret = 0;
-        int retry = 1;
-
-        start_pfn = PFN_DOWN(start);
-        end_pfn = PFN_UP(start + size - 1);
-
-        /*
-         * When CONFIG_MEMCG is on, one memory block may be used by other
-         * blocks to store page cgroup when onlining pages. But we don't know
-         * in what order pages are onlined. So we iterate twice to offline
-         * memory:
-         * 1st iterate: offline every non primary memory block.
-         * 2nd iterate: offline primary (i.e. first added) memory block.
-         */
-repeat:
-        walk_memory_range(start_pfn, end_pfn, &ret,
-                          offline_memory_block_cb);
-        if (ret) {
-                if (!retry)
-                        return ret;
-
-                retry = 0;
-                ret = 0;
-                goto repeat;
-        }
+        int ret;
 
         lock_memory_hotplug();
 
         /*
-         * we have offlined all memory blocks like this:
-         *   1. lock memory hotplug
-         *   2. offline a memory block
-         *   3. unlock memory hotplug
-         *
-         * repeat step1-3 to offline the memory block. All memory blocks
-         * must be offlined before removing memory. But we don't hold the
-         * lock in the whole operation. So we should check whether all
-         * memory blocks are offlined.
+         * All memory blocks must be offlined before removing memory.  Check
+         * whether all memory blocks in question are offline and trigger a BUG()
+         * if this is not the case.
          */
-
-        ret = walk_memory_range(start_pfn, end_pfn, NULL,
+        ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL,
                                 is_memblock_offlined_cb);
         if (ret) {
                 unlock_memory_hotplug();
-                return ret;
+                BUG();
         }
 
         /* remove memmap entry */
@@ -1872,17 +1824,6 @@ repeat:
         try_offline_node(nid);
 
         unlock_memory_hotplug();
-
-        return 0;
 }
-#else
-int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
-{
-        return -EINVAL;
-}
-int remove_memory(int nid, u64 start, u64 size)
-{
-        return -EINVAL;
-}
-#endif /* CONFIG_MEMORY_HOTREMOVE */
 EXPORT_SYMBOL_GPL(remove_memory);
+#endif /* CONFIG_MEMORY_HOTREMOVE */