mm, page_owner: dump page owner info from dump_page()

[mirror_ubuntu-artful-kernel.git] / mm / page_owner.c

diff --git a/mm/page_owner.c b/mm/page_owner.c
index a57068cfe52fdcb4758e673e7bc82df0dfb51509..44ad1f00c4e1ce8e356c94bbc751fc544f7c7229 100644 (file)
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -183,6 +183,31 @@ err:
        return -ENOMEM;
 }
 
+void __dump_page_owner(struct page *page)
+{
+       struct page_ext *page_ext = lookup_page_ext(page);
+       struct stack_trace trace = {
+               .nr_entries = page_ext->nr_entries,
+               .entries = &page_ext->trace_entries[0],
+       };
+       gfp_t gfp_mask = page_ext->gfp_mask;
+       int mt = gfpflags_to_migratetype(gfp_mask);
+
+       if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) {
+               pr_alert("page_owner info is not active (free page?)\n");
+               return;
+       }
+
+       pr_alert("page allocated via order %u, migratetype %s, "
+                       "gfp_mask %#x(%pGg)\n", page_ext->order,
+                       migratetype_names[mt], gfp_mask, &gfp_mask);
+       print_stack_trace(&trace, 0);
+
+       if (page_ext->last_migrate_reason != -1)
+               pr_alert("page has been migrated, last migrate reason: %s\n",
+                       migrate_reason_names[page_ext->last_migrate_reason]);
+}
+
 static ssize_t
 read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 {