proc/smaps: show amount of nonlinear ptes in vma
Currently, nonlinear mappings can not be distinguished from ordinary
mappings. This patch adds into /proc/pid/smaps line "Nonlinear: <size>
kB", where size is amount of nonlinear ptes in vma, this line appears only
if VM_NONLINEAR is set. This information may be useful not only for
checkpoint/restore project.
Requested by Pavel Emelyanov.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Pavel Emelyanov <xemul@parallels.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>
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index e2c1155..4540b8f 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -393,6 +393,7 @@
unsigned long anonymous;
unsigned long anonymous_thp;
unsigned long swap;
+ unsigned long nonlinear;
u64 pss;
};
@@ -402,6 +403,7 @@
{
struct mem_size_stats *mss = walk->private;
struct vm_area_struct *vma = mss->vma;
+ pgoff_t pgoff = linear_page_index(vma, addr);
struct page *page = NULL;
int mapcount;
@@ -414,6 +416,9 @@
mss->swap += ptent_size;
else if (is_migration_entry(swpent))
page = migration_entry_to_page(swpent);
+ } else if (pte_file(ptent)) {
+ if (pte_to_pgoff(ptent) != pgoff)
+ mss->nonlinear += ptent_size;
}
if (!page)
@@ -422,6 +427,9 @@
if (PageAnon(page))
mss->anonymous += ptent_size;
+ if (page->index != pgoff)
+ mss->nonlinear += ptent_size;
+
mss->resident += ptent_size;
/* Accumulate the size in pages that have been accessed. */
if (pte_young(ptent) || PageReferenced(page))
@@ -523,6 +531,10 @@
(vma->vm_flags & VM_LOCKED) ?
(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);
+ if (vma->vm_flags & VM_NONLINEAR)
+ seq_printf(m, "Nonlinear: %8lu kB\n",
+ mss.nonlinear >> 10);
+
if (m->count < m->size) /* vma is copied successfully */
m->version = (vma != get_gate_vma(task->mm))
? vma->vm_start : 0;