[patch 2/3 take2] smaps: add pages referenced count to smaps

David Rientjes
2007-02-07T06:16:08Z

Adds an additional unsigned long field to struct mem_size_stats:
referenced. For each page table entry that is walked for the VMA in the
smaps code, this field is incremented by PAGE_SIZE if it has pte-reference
bits.

An additional line was added to the /proc/pid/smaps output for each VMA
to indicate how many pages within it are currently marked as accessed
(referenced).

Cc: Hugh Dickins <hugh@veritas.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
---
fs/proc/task_mmu.c | 20 +++++++++++++-------
1 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index e87824b..50bd004 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -120,6 +120,7 @@ struct mem_size_stats
unsigned long shared_dirty;
unsigned long private_clean;
unsigned long private_dirty;
+ unsigned long referenced;
};

struct pte_walker {
@@ -190,18 +191,20 @@ static int show_map_internal(struct seq_file *m, void *v, struct mem_size_stats

if (mss)
seq_printf(m,
- "Size: %8lu kB\n"
- "Rss: %8lu kB\n"
- "Shared_Clean: %8lu kB\n"
- "Shared_Dirty: %8lu kB\n"
- "Private_Clean: %8lu kB\n"
- "Private_Dirty: %8lu kB\n",
+ "Size: %8lu kB\n"
+ "Rss: %8lu kB\n"
+ "Shared_Clean: %8lu kB\n"
+ "Shared_Dirty: %8lu kB\n"
+ "Private_Clean: %8lu kB\n"
+ "Private_Dirty: %8lu kB\n"
+ "Pgs_Referenced: %8lu kB\n",
(vma->vm_end - vma->vm_start) >> 10,
mss->resident >> 10,
mss->shared_clean >> 10,
mss->shared_dirty >> 10,
mss->private_clean >> 10,
- mss->private_dirty >> 10);
+ mss->private_dirty >> 10,
+ mss->referenced >> 10);

if (m->count < m->size) /* vma is copied successfully */
m->version = (vma != get_gate_vma(task))? vma->vm_start: 0;
@@ -302,6 +305,9 @@ static void smaps_pte_func(struct pte_walker *walker, pte_t *pte,
if (!page)
return;

+ /* Accumulate the number of pages that have been accessed. */
+ if (pte_young(ptent) || PageReferenced(page))
+ mss->referenced += PAGE_SIZE;
if (page_mapcount(page) >= 2) {
if (pte_dirty(ptent))
mss->shared_dirty += PAGE_SIZE;