mm, show_mem: remove SHOW_MEM_FILTER_PAGE_COUNT

Commit 4b59e6c47309 ("mm, show_mem: suppress page counts in
non-blockable contexts") introduced SHOW_MEM_FILTER_PAGE_COUNT to
suppress PFN walks on large memory machines.  Commit c78e93630d15 ("mm:
do not walk all of system memory during show_mem") avoided a PFN walk in
the generic show_mem helper which removes the requirement for
SHOW_MEM_FILTER_PAGE_COUNT in that case.

This patch removes PFN walkers from the arch-specific implementations
that report on a per-node or per-zone granularity.  ARM and unicore32
still do a PFN walk as they report memory usage on each bank which is a
much finer granularity where the debugging information may still be of
use.  As the remaining arches doing PFN walks have relatively small
amounts of memory, this patch simply removes SHOW_MEM_FILTER_PAGE_COUNT.

[akpm@linux-foundation.org: fix parisc]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 42 deletions

diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 96f8168cf4ec..ae085ad0fba0 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -645,55 +645,30 @@ EXPORT_SYMBOL(empty_zero_page);
 
 void show_mem(unsigned int filter)
 {
-        int i,free = 0,total = 0,reserved = 0;
-        int shared = 0, cached = 0;
+        int total = 0,reserved = 0;
+        pg_data_t *pgdat;
 
         printk(KERN_INFO "Mem-info:\n");
         show_free_areas(filter);
-        if (filter & SHOW_MEM_FILTER_PAGE_COUNT)
-                return;
-#ifndef CONFIG_DISCONTIGMEM
-        i = max_mapnr;
-        while (i-- > 0) {
-                total++;
-                if (PageReserved(mem_map+i))
-                        reserved++;
-                else if (PageSwapCache(mem_map+i))
-                        cached++;
-                else if (!page_count(&mem_map[i]))
-                        free++;
-                else
-                        shared += page_count(&mem_map[i]) - 1;
-        }
-#else
-        for (i = 0; i < npmem_ranges; i++) {
-                int j;
 
-                for (j = node_start_pfn(i); j < node_end_pfn(i); j++) {
-                        struct page *p;
-                        unsigned long flags;
-
-                        pgdat_resize_lock(NODE_DATA(i), &flags);
-                        p = nid_page_nr(i, j) - node_start_pfn(i);
-
-                        total++;
-                        if (PageReserved(p))
-                                reserved++;
-                        else if (PageSwapCache(p))
-                                cached++;
-                        else if (!page_count(p))
-                                free++;
-                        else
-                                shared += page_count(p) - 1;
-                        pgdat_resize_unlock(NODE_DATA(i), &flags);
-                }
+        for_each_online_pgdat(pgdat) {
+                unsigned long flags;
+                int zoneid;
+
+                pgdat_resize_lock(pgdat, &flags);
+                for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) {
+                        struct zone *zone = &pgdat->node_zones[zoneid];
+                        if (!populated_zone(zone))
+                                continue;
+
+                        total += zone->present_pages;
+                        reserved = zone->present_pages - zone->managed_pages;
+                }
+                pgdat_resize_unlock(pgdat, &flags);
         }
-#endif
+
         printk(KERN_INFO "%d pages of RAM\n", total);
         printk(KERN_INFO "%d reserved pages\n", reserved);
-        printk(KERN_INFO "%d pages shared\n", shared);
-        printk(KERN_INFO "%d pages swap cached\n", cached);
-
 
 #ifdef CONFIG_DISCONTIGMEM
         {