vmscan: report vm_flags in page_referenced()

Collect vma->vm_flags of the VMAs that actually referenced the page.

This is preparing for more informed reclaim heuristics, eg.  to protect
executable file pages more aggressively.  For now only the VM_EXEC bit
will be used by the caller.

Thanks to Johannes, Peter and Minchan for all the good tips.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 52339dd7bf85..6be2068f61c8 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -577,6 +577,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
         struct pagevec freed_pvec;
         int pgactivate = 0;
         unsigned long nr_reclaimed = 0;
+        unsigned long vm_flags;
 
         cond_resched();
 
@@ -627,7 +628,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
                                 goto keep_locked;
                 }
 
-                referenced = page_referenced(page, 1, sc->mem_cgroup);
+                referenced = page_referenced(page, 1,
+                                                sc->mem_cgroup, &vm_flags);
                 /* In active use or really unfreeable?  Activate it. */
                 if (sc->order <= PAGE_ALLOC_COSTLY_ORDER &&
                                         referenced && page_mapping_inuse(page))
@@ -1208,6 +1210,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 {
         unsigned long pgmoved;
         unsigned long pgscanned;
+        unsigned long vm_flags;
         LIST_HEAD(l_hold);      /* The pages which were snipped off */
         LIST_HEAD(l_inactive);
         struct page *page;
@@ -1248,7 +1251,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 
                 /* page_referenced clears PageReferenced */
                 if (page_mapping_inuse(page) &&
-                    page_referenced(page, 0, sc->mem_cgroup))
+                    page_referenced(page, 0, sc->mem_cgroup, &vm_flags))
                         pgmoved++;
 
                 list_add(&page->lru, &l_inactive);