mm: rename global_page_state to global_zone_page_state

global_page_state is error prone as a recent bug report pointed out [1].
It only returns proper values for zone based counters as the enum it
gets suggests.  We already have global_node_page_state so let's rename
global_page_state to global_zone_page_state to be more explicit here.
All existing users seems to be correct:

$ git grep "global_page_state(NR_" | sed 's@.*(\(NR_[A-Z_]*\)).*@\1@' | sort | uniq -c
      2 NR_BOUNCE
      2 NR_FREE_CMA_PAGES
     11 NR_FREE_PAGES
      1 NR_KERNEL_STACK_KB
      1 NR_MLOCK
      2 NR_PAGETABLE

This patch shouldn't introduce any functional change.

[1] http://lkml.kernel.org/r/201707260628.v6Q6SmaS030814@www262.sakura.ne.jp

Link: http://lkml.kernel.org/r/20170801134256.5400-2-hannes@cmpxchg.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 16 insertions, 16 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index f19efcf75418..9800e29763f4 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3514,7 +3514,7 @@ static int init_user_reserve(void)
 {
         unsigned long free_kbytes;
 
-        free_kbytes = global_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
+        free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
 
         sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17);
         return 0;
@@ -3535,7 +3535,7 @@ static int init_admin_reserve(void)
 {
         unsigned long free_kbytes;
 
-        free_kbytes = global_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
+        free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
 
         sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13);
         return 0;
@@ -3579,7 +3579,7 @@ static int reserve_mem_notifier(struct notifier_block *nb,
 
                 break;
         case MEM_OFFLINE:
-                free_kbytes = global_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
+                free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
 
                 if (sysctl_user_reserve_kbytes > free_kbytes) {
                         init_user_reserve();
diff --git a/mm/nommu.c b/mm/nommu.c
index fc184f597d59..53d5175a5c14 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1962,7 +1962,7 @@ static int __meminit init_user_reserve(void)
 {
         unsigned long free_kbytes;
 
-        free_kbytes = global_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
+        free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
 
         sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17);
         return 0;
@@ -1983,7 +1983,7 @@ static int __meminit init_admin_reserve(void)
 {
         unsigned long free_kbytes;
 
-        free_kbytes = global_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
+        free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
 
         sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13);
         return 0;
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index bf050ab025b7..0b9c5cbe8eba 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -363,7 +363,7 @@ static unsigned long global_dirtyable_memory(void)
 {
         unsigned long x;
 
-        x = global_page_state(NR_FREE_PAGES);
+        x = global_zone_page_state(NR_FREE_PAGES);
         /*
          * Pages reserved for the kernel should not be considered
          * dirtyable, to prevent a situation where reclaim has to
@@ -1405,7 +1405,7 @@ void wb_update_bandwidth(struct bdi_writeback *wb, unsigned long start_time)
  * will look to see if it needs to start dirty throttling.
  *
  * If dirty_poll_interval is too low, big NUMA machines will call the expensive
- * global_page_state() too often. So scale it near-sqrt to the safety margin
+ * global_zone_page_state() too often. So scale it near-sqrt to the safety margin
  * (the number of pages we may dirty without exceeding the dirty limits).
  */
 static unsigned long dirty_poll_interval(unsigned long dirty,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0bea94af0423..a4562c058ec4 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4509,7 +4509,7 @@ long si_mem_available(void)
          * Estimate the amount of memory available for userspace allocations,
          * without causing swapping.
          */
-        available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
+        available = global_zone_page_state(NR_FREE_PAGES) - totalreserve_pages;
 
         /*
          * Not all the page cache can be freed, otherwise the system will
@@ -4538,7 +4538,7 @@ void si_meminfo(struct sysinfo *val)
 {
         val->totalram = totalram_pages;
         val->sharedram = global_node_page_state(NR_SHMEM);
-        val->freeram = global_page_state(NR_FREE_PAGES);
+        val->freeram = global_zone_page_state(NR_FREE_PAGES);
         val->bufferram = nr_blockdev_pages();
         val->totalhigh = totalhigh_pages;
         val->freehigh = nr_free_highpages();
@@ -4673,11 +4673,11 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
                 global_node_page_state(NR_SLAB_UNRECLAIMABLE),
                 global_node_page_state(NR_FILE_MAPPED),
                 global_node_page_state(NR_SHMEM),
-                global_page_state(NR_PAGETABLE),
-                global_page_state(NR_BOUNCE),
-                global_page_state(NR_FREE_PAGES),
+                global_zone_page_state(NR_PAGETABLE),
+                global_zone_page_state(NR_BOUNCE),
+                global_zone_page_state(NR_FREE_PAGES),
                 free_pcp,
-                global_page_state(NR_FREE_CMA_PAGES));
+                global_zone_page_state(NR_FREE_CMA_PAGES));
 
         for_each_online_pgdat(pgdat) {
                 if (show_mem_node_skip(filter, pgdat->node_id, nodemask))
diff --git a/mm/util.c b/mm/util.c
index 9ecddf568fe3..34e57fae959d 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -614,7 +614,7 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
                 return 0;
 
         if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) {
-                free = global_page_state(NR_FREE_PAGES);
+                free = global_zone_page_state(NR_FREE_PAGES);
                 free += global_node_page_state(NR_FILE_PAGES);
 
                 /*
diff --git a/mm/vmstat.c b/mm/vmstat.c
index e131b51654c7..ba9b202e8500 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1502,7 +1502,7 @@ static void *vmstat_start(struct seq_file *m, loff_t *pos)
         if (!v)
                 return ERR_PTR(-ENOMEM);
         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
-                v[i] = global_page_state(i);
+                v[i] = global_zone_page_state(i);
         v += NR_VM_ZONE_STAT_ITEMS;
 
         for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
@@ -1591,7 +1591,7 @@ int vmstat_refresh(struct ctl_table *table, int write,
          * which can equally be echo'ed to or cat'ted from (by root),
          * can be used to update the stats just before reading them.
          *
-         * Oh, and since global_page_state() etc. are so careful to hide
+         * Oh, and since global_zone_page_state() etc. are so careful to hide
          * transiently negative values, report an error here if any of
          * the stats is negative, so we know to go looking for imbalance.
          */