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>

1 files changed, 6 insertions, 6 deletions

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))