Import wiredtiger: d29619b755d79cb4406349e1309935b8c2fda2c2 from branch mongodb-4.6

ref: 54d5655b43..d29619b755
for: 4.5.1

WT-6274       SESSIONs shouldn't nest calls to get/release hs cursor
WT-6421       Avoid parsing metadata checkpoint for clean files
WT-6466       Don't reset the WT_SESSION timers when HS cursors are closed
WT-6551       Avoid a timing problem at the beginning of a test for log preallocation

1 files changed, 15 insertions, 0 deletions

diff --git a/src/third_party/wiredtiger/src/include/btree.h b/src/third_party/wiredtiger/src/include/btree.h
index ca639abd6ca..8ec0953c378 100644
--- a/src/third_party/wiredtiger/src/include/btree.h
+++ b/src/third_party/wiredtiger/src/include/btree.h
@@ -203,6 +203,21 @@ struct __wt_btree {
      */
     uint64_t file_max;
 
+/*
+ * We maintain a timer for a clean file to avoid excessive checking of checkpoint information that
+ * incurs a large processing penalty. We avoid that but will periodically incur the cost to clean up
+ * checkpoints that can be deleted.
+ */
+#define WT_BTREE_CLEAN_CKPT(session, btree, val)                          \
+    do {                                                                  \
+        (btree)->clean_ckpt_timer = (val);                                \
+        WT_STAT_DATA_SET((session), btree_clean_checkpoint_timer, (val)); \
+    } while (0)
+/* Statistics don't like UINT64_MAX, use INT64_MAX. It's still forever. */
+#define WT_BTREE_CLEAN_CKPT_FOREVER INT64_MAX
+#define WT_BTREE_CLEAN_MINUTES 10
+    uint64_t clean_ckpt_timer;
+
     /*
      * We flush pages from the tree (in order to make checkpoint faster), without a high-level lock.
      * To avoid multiple threads flushing at the same time, lock the tree.