commit: add short-circuit to paint_down_to_common()

diff --git a/name-hash.c b/name-hash.c
index bd8dc7a6a7498d42f2576eb866e97dd55797194d..ada66f066a002ac5ecb73f94a582d758c0a3a657 100644 (file)
--- a/name-hash.c
+++ b/name-hash.c
@@ -578,15 +578,23 @@ static void threaded_lazy_init_name_hash(
 
 static void lazy_init_name_hash(struct index_state *istate)
 {
+       uint64_t start = getnanotime();
+
        if (istate->name_hash_initialized)
                return;
        hashmap_init(&istate->name_hash, cache_entry_cmp, NULL, istate->cache_nr);
        hashmap_init(&istate->dir_hash, dir_entry_cmp, NULL, istate->cache_nr);
 
        if (lookup_lazy_params(istate)) {
-               hashmap_disallow_rehash(&istate->dir_hash, 1);
+               /*
+                * Disable item counting and automatic rehashing because
+                * we do per-chain (mod n) locking rather than whole hashmap
+                * locking and we need to prevent the table-size from changing
+                * and bucket items from being redistributed.
+                */
+               hashmap_disable_item_counting(&istate->dir_hash);
                threaded_lazy_init_name_hash(istate);
-               hashmap_disallow_rehash(&istate->dir_hash, 0);
+               hashmap_enable_item_counting(&istate->dir_hash);
        } else {
                int nr;
                for (nr = 0; nr < istate->cache_nr; nr++)
@@ -594,6 +602,7 @@ static void lazy_init_name_hash(struct index_state *istate)
        }
 
        istate->name_hash_initialized = 1;
+       trace_performance_since(start, "initialize name hash");
 }
 
 /*