[PATCH RFC v2 6/6] mm: Add heap quarantine verbose debugging (not for merge)

[Alexander Popov]

Add verbose debugging for deeper understanding of the heap quarantine
inner workings (this patch is not for merge).

Signed-off-by: Alexander Popov <alex.po...@linux.com>
---
 mm/kasan/quarantine.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c
index 4ce100605086..98cd6e963755 100644
--- a/mm/kasan/quarantine.c
+++ b/mm/kasan/quarantine.c
@@ -203,6 +203,12 @@ void quarantine_put(struct kasan_free_meta *info, struct 
kmem_cache *cache)
                qlist_move_all(q, &temp);
 
                raw_spin_lock(&quarantine_lock);
+
+               pr_info("quarantine: PUT %zu to tail batch %d, whole sz %zu, 
batch sz %lu\n",
+                               temp.bytes, quarantine_tail,
+                               READ_ONCE(quarantine_size),
+                               READ_ONCE(quarantine_batch_size));
+
                WRITE_ONCE(quarantine_size, quarantine_size + temp.bytes);
                qlist_move_all(&temp, &global_quarantine[quarantine_tail]);
                if (global_quarantine[quarantine_tail].bytes >=
@@ -313,7 +319,22 @@ void quarantine_reduce(void)
                        quarantine_head = get_random_int() % QUARANTINE_BATCHES;
                } while (quarantine_head == quarantine_tail);
                qlist_move_random(&global_quarantine[quarantine_head], 
&to_free);
+               pr_info("quarantine: whole sz exceed max by %lu, REDUCE head 
batch %d by %zu, leave %zu\n",
+                               quarantine_size - quarantine_max_size,
+                               quarantine_head, to_free.bytes,
+                               global_quarantine[quarantine_head].bytes);
                WRITE_ONCE(quarantine_size, quarantine_size - to_free.bytes);
+
+               if (quarantine_head == 0) {
+                       unsigned long i;
+
+                       pr_info("quarantine: data level in batches:");
+                       for (i = 0; i < QUARANTINE_BATCHES; i++) {
+                               pr_info("  %lu - %lu%%\n",
+                                       i, global_quarantine[i].bytes *
+                                               100 / quarantine_batch_size);
+                       }
+               }
        }
 #endif
 
-- 
2.26.2