mm: report the MMU pagesize in /proc/pid/smaps

The KernelPageSize entry in /proc/pid/smaps is the pagesize used by the
kernel to back a VMA.  This matches the size used by the MMU in the
majority of cases.  However, one counter-example occurs on PPC64 kernels
whereby a kernel using 64K as a base pagesize may still use 4K pages for
the MMU on older processor.  To distinguish, this patch reports
MMUPageSize as the pagesize used by the MMU in /proc/pid/smaps.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 41ef5f23e779..94063840832a 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -397,7 +397,8 @@ static int show_smap(struct seq_file *m, void *v)
                    "Private_Dirty:  %8lu kB\n"
                    "Referenced:     %8lu kB\n"
                    "Swap:           %8lu kB\n"
-                   "KernelPageSize: %8lu kB\n",
+                   "KernelPageSize: %8lu kB\n"
+                   "MMUPageSize:    %8lu kB\n",
                    (vma->vm_end - vma->vm_start) >> 10,
                    mss.resident >> 10,
                    (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
@@ -407,7 +408,8 @@ static int show_smap(struct seq_file *m, void *v)
                    mss.private_dirty >> 10,
                    mss.referenced >> 10,
                    mss.swap >> 10,
-                   vma_kernel_pagesize(vma) >> 10);
+                   vma_kernel_pagesize(vma) >> 10,
+                   vma_mmu_pagesize(vma) >> 10);
 
         if (m->count < m->size)  /* vma is copied successfully */
                 m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0;