diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b5468de..a8c003e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2051,8 +2051,8 @@
 
 /**
  * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
- * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed
- * @max_low_pfn: The highest PFN that till be passed to free_bootmem_node
+ * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
+ * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
  *
  * If an architecture guarantees that all ranges registered with
  * add_active_ranges() contain no holes and may be freed, this
@@ -2082,11 +2082,11 @@
 
 /**
  * sparse_memory_present_with_active_regions - Call memory_present for each active range
- * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used
+ * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
  *
  * If an architecture guarantees that all ranges registered with
  * add_active_ranges() contain no holes and may be freed, this
- * this function may be used instead of calling memory_present() manually.
+ * function may be used instead of calling memory_present() manually.
  */
 void __init sparse_memory_present_with_active_regions(int nid)
 {
@@ -2156,14 +2156,14 @@
 
 /**
  * get_pfn_range_for_nid - Return the start and end page frames for a node
- * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned
- * @start_pfn: Passed by reference. On return, it will have the node start_pfn
- * @end_pfn: Passed by reference. On return, it will have the node end_pfn
+ * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
+ * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
+ * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
  *
  * It returns the start and end page frame of a node based on information
  * provided by an arch calling add_active_range(). If called for a node
  * with no available memory, a warning is printed and the start and end
- * PFNs will be 0
+ * PFNs will be 0.
  */
 void __init get_pfn_range_for_nid(unsigned int nid,
 			unsigned long *start_pfn, unsigned long *end_pfn)
@@ -2216,7 +2216,7 @@
 
 /*
  * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
- * then all holes in the requested range will be accounted for
+ * then all holes in the requested range will be accounted for.
  */
 unsigned long __init __absent_pages_in_range(int nid,
 				unsigned long range_start_pfn,
@@ -2269,7 +2269,7 @@
  * @start_pfn: The start PFN to start searching for holes
  * @end_pfn: The end PFN to stop searching for holes
  *
- * It returns the number of pages frames in memory holes within a range
+ * It returns the number of pages frames in memory holes within a range.
  */
 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
 							unsigned long end_pfn)
@@ -2583,11 +2583,12 @@
 
 /**
  * remove_all_active_ranges - Remove all currently registered regions
+ *
  * During discovery, it may be found that a table like SRAT is invalid
  * and an alternative discovery method must be used. This function removes
  * all currently registered regions.
  */
-void __init remove_all_active_ranges()
+void __init remove_all_active_ranges(void)
 {
 	memset(early_node_map, 0, sizeof(early_node_map));
 	nr_nodemap_entries = 0;
@@ -2637,7 +2638,7 @@
  * find_min_pfn_with_active_regions - Find the minimum PFN registered
  *
  * It returns the minimum PFN based on information provided via
- * add_active_range()
+ * add_active_range().
  */
 unsigned long __init find_min_pfn_with_active_regions(void)
 {
@@ -2648,7 +2649,7 @@
  * find_max_pfn_with_active_regions - Find the maximum PFN registered
  *
  * It returns the maximum PFN based on information provided via
- * add_active_range()
+ * add_active_range().
  */
 unsigned long __init find_max_pfn_with_active_regions(void)
 {
@@ -2663,10 +2664,7 @@
 
 /**
  * free_area_init_nodes - Initialise all pg_data_t and zone data
- * @arch_max_dma_pfn: The maximum PFN usable for ZONE_DMA
- * @arch_max_dma32_pfn: The maximum PFN usable for ZONE_DMA32
- * @arch_max_low_pfn: The maximum PFN usable for ZONE_NORMAL
- * @arch_max_high_pfn: The maximum PFN usable for ZONE_HIGHMEM
+ * @max_zone_pfn: an array of max PFNs for each zone
  *
  * This will call free_area_init_node() for each active node in the system.
  * Using the page ranges provided by add_active_range(), the size of each
@@ -2724,14 +2722,15 @@
 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
 
 /**
- * set_dma_reserve - Account the specified number of pages reserved in ZONE_DMA
- * @new_dma_reserve - The number of pages to mark reserved
+ * set_dma_reserve - set the specified number of pages reserved in the first zone
+ * @new_dma_reserve: The number of pages to mark reserved
  *
  * The per-cpu batchsize and zone watermarks are determined by present_pages.
  * In the DMA zone, a significant percentage may be consumed by kernel image
  * and other unfreeable allocations which can skew the watermarks badly. This
- * function may optionally be used to account for unfreeable pages in
- * ZONE_DMA. The effect will be lower watermarks and smaller per-cpu batchsize
+ * function may optionally be used to account for unfreeable pages in the
+ * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
+ * smaller per-cpu batchsize.
  */
 void __init set_dma_reserve(unsigned long new_dma_reserve)
 {
@@ -2844,10 +2843,11 @@
 	calculate_totalreserve_pages();
 }
 
-/*
- * setup_per_zone_pages_min - called when min_free_kbytes changes.  Ensures 
- *	that the pages_{min,low,high} values for each zone are set correctly 
- *	with respect to min_free_kbytes.
+/**
+ * setup_per_zone_pages_min - called when min_free_kbytes changes.
+ *
+ * Ensures that the pages_{min,low,high} values for each zone are set correctly
+ * with respect to min_free_kbytes.
  */
 void setup_per_zone_pages_min(void)
 {