[IA64] fix show_mem for VIRTUAL_MEM_MAP+FLATMEM

contig.c (FLATMEM) requires the same optimization as in discontig.c for show_mem
when VIRTUAL_MEM_MAP is in use. Otherwise FLATMEM has softlockup timeouts.
This was boot tested for memory configuration: SPARSEMEM,
DISCONTIG+VIRTUAL_MEM_MAP, FLATMEM, FLATMEM+VIRTUAL_MEM_MAP and
FLATMEM+VIRTUAL_MEM_MAP with largest memory gap less than LARGE_GAP by
using boot parameter "mem=".

This was boot tested and "echo m >/proc/sysrq-trigger" output evaluated for
: FLATMEM, FLATMEM+VIRTUAL_MEM_MAP, DISCONTIGMEM+VIRTUAL_MEM_MAP and
SPARSEMEM.

Signed-off-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/arch/ia64/mm/contig.c b/arch/ia64/mm/contig.c
index 8919fed9666a..e004143ba86b 100644
--- a/arch/ia64/mm/contig.c
+++ b/arch/ia64/mm/contig.c
@@ -27,6 +27,7 @@
 
 #ifdef CONFIG_VIRTUAL_MEM_MAP
 static unsigned long num_dma_physpages;
+static unsigned long max_gap;
 #endif
 
 /**
@@ -45,9 +46,15 @@ show_mem (void)
 
         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
         i = max_mapnr;
-        while (i-- > 0) {
-                if (!pfn_valid(i))
+        for (i = 0; i < max_mapnr; i++) {
+                if (!pfn_valid(i)) {
+#ifdef CONFIG_VIRTUAL_MEM_MAP
+                        if (max_gap < LARGE_GAP)
+                                continue;
+                        i = vmemmap_find_next_valid_pfn(0, i) - 1;
+#endif
                         continue;
+                }
                 total++;
                 if (PageReserved(mem_map+i))
                         reserved++;
@@ -234,7 +241,6 @@ paging_init (void)
         unsigned long zones_size[MAX_NR_ZONES];
 #ifdef CONFIG_VIRTUAL_MEM_MAP
         unsigned long zholes_size[MAX_NR_ZONES];
-        unsigned long max_gap;
 #endif
 
         /* initialize mem_map[] */
@@ -266,7 +272,6 @@ paging_init (void)
                 }
         }
 
-        max_gap = 0;
         efi_memmap_walk(find_largest_hole, (u64 *)&max_gap);
         if (max_gap < LARGE_GAP) {
                 vmem_map = (struct page *) 0;