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Diffstat (limited to 'mm/vmstat.c')
-rw-r--r--mm/vmstat.c23
1 files changed, 20 insertions, 3 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 4e885ecd44d1..a8222041bd44 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1383,12 +1383,29 @@ static void pagetypeinfo_showfree_print(struct seq_file *m,
unsigned long freecount = 0;
struct free_area *area;
struct list_head *curr;
+ bool overflow = false;
area = &(zone->free_area[order]);
- list_for_each(curr, &area->free_list[mtype])
- freecount++;
- seq_printf(m, "%6lu ", freecount);
+ list_for_each(curr, &area->free_list[mtype]) {
+ /*
+ * Cap the free_list iteration because it might
+ * be really large and we are under a spinlock
+ * so a long time spent here could trigger a
+ * hard lockup detector. Anyway this is a
+ * debugging tool so knowing there is a handful
+ * of pages of this order should be more than
+ * sufficient.
+ */
+ if (++freecount >= 100000) {
+ overflow = true;
+ break;
+ }
+ }
+ seq_printf(m, "%s%6lu ", overflow ? ">" : "", freecount);
+ spin_unlock_irq(&zone->lock);
+ cond_resched();
+ spin_lock_irq(&zone->lock);
}
seq_putc(m, '\n');
}