X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Ftdb2%2Ffree.c;h=dca8ff10709c81e3848b0c1fb9e3e4431ed0996f;hb=afc3c1e723b4eca0b32f7c5b656f5b070eb1c9fb;hp=8ff5d74a3fd7a8a400b243b9dd8a22c1dfe44af6;hpb=20defbbcfa088a7574d9897b533d1bc600b2df53;p=ccan

diff --git a/ccan/tdb2/free.c b/ccan/tdb2/free.c
index 8ff5d74a..dca8ff10 100644
--- a/ccan/tdb2/free.c
+++ b/ccan/tdb2/free.c
@@ -244,12 +244,15 @@ static size_t record_leftover(size_t keylen, size_t datalen,
 	return leftover;
 }
 
-/* FIXME: Shortcut common case where tdb->flist == flist */
 static tdb_off_t flist_offset(struct tdb_context *tdb, unsigned int flist)
 {
-	tdb_off_t off = first_flist(tdb);
+	tdb_off_t off;
 	unsigned int i;
 
+	if (likely(tdb->flist == flist))
+		return tdb->flist_off;
+
+	off = first_flist(tdb);
 	for (i = 0; i < flist; i++)
 		off = next_flist(tdb, off);
 	return off;
@@ -262,6 +265,7 @@ static int coalesce(struct tdb_context *tdb,
 	struct tdb_free_record pad, *r;
 	tdb_off_t end;
 
+	add_stat(tdb, alloc_coalesce_tried, 1);
 	end = off + sizeof(struct tdb_used_record) + data_len;
 
 	while (end < tdb->map_size) {
@@ -281,8 +285,10 @@ static int coalesce(struct tdb_context *tdb,
 		nb_off = bucket_off(flist_offset(tdb, flist), bucket);
 
 		/* We may be violating lock order here, so best effort. */
-		if (tdb_lock_free_bucket(tdb, nb_off, TDB_LOCK_NOWAIT) == -1)
+		if (tdb_lock_free_bucket(tdb, nb_off, TDB_LOCK_NOWAIT) == -1) {
+			add_stat(tdb, alloc_coalesce_lockfail, 1);
 			break;
+		}
 
 		/* Now we have lock, re-check. */
 		r = tdb_get(tdb, end, &pad, sizeof(pad));
@@ -292,12 +298,14 @@ static int coalesce(struct tdb_context *tdb,
 		}
 
 		if (unlikely(frec_magic(r) != TDB_FREE_MAGIC)) {
+			add_stat(tdb, alloc_coalesce_race, 1);
 			tdb_unlock_free_bucket(tdb, nb_off);
 			break;
 		}
 
 		if (unlikely(frec_flist(r) != flist)
 		    || unlikely(size_to_bucket(frec_len(r)) != bucket)) {
+			add_stat(tdb, alloc_coalesce_race, 1);
 			tdb_unlock_free_bucket(tdb, nb_off);
 			break;
 		}
@@ -309,6 +317,7 @@ static int coalesce(struct tdb_context *tdb,
 
 		end += sizeof(struct tdb_used_record) + frec_len(r);
 		tdb_unlock_free_bucket(tdb, nb_off);
+		add_stat(tdb, alloc_coalesce_num_merged, 1);
 	}
 
 	/* Didn't find any adjacent free? */
@@ -343,6 +352,7 @@ static int coalesce(struct tdb_context *tdb,
 	if (tdb_access_commit(tdb, r) != 0)
 		goto err;
 
+	add_stat(tdb, alloc_coalesce_succeeded, 1);
 	tdb_unlock_free_bucket(tdb, b_off);
 
 	if (add_free_record(tdb, off, end - off) == -1)
@@ -368,6 +378,7 @@ static tdb_off_t lock_and_alloc(struct tdb_context *tdb,
 	double multiplier;
 	size_t size = adjust_size(keylen, datalen);
 
+	add_stat(tdb, allocs, 1);
 again:
 	b_off = bucket_off(flist_off, bucket);
 
@@ -450,15 +461,18 @@ again:
 		if (tdb_write_convert(tdb, best_off, &rec, sizeof(rec)) != 0)
 			goto unlock_err;
 
-		tdb_unlock_free_bucket(tdb, b_off);
-
+		/* Bucket of leftover will be <= current bucket, so nested
+		 * locking is allowed. */
 		if (leftover) {
+			add_stat(tdb, alloc_leftover, 1);
 			if (add_free_record(tdb,
 					    best_off + sizeof(rec)
 					    + frec_len(&best) - leftover,
 					    leftover))
-				return TDB_OFF_ERR;
+				best_off = TDB_OFF_ERR;
 		}
+		tdb_unlock_free_bucket(tdb, b_off);
+
 		return best_off;
 	}
 
@@ -500,6 +514,10 @@ static tdb_off_t get_free(struct tdb_context *tdb,
 			if (off == TDB_OFF_ERR)
 				return TDB_OFF_ERR;
 			if (off != 0) {
+				if (b == start_b)
+					add_stat(tdb, alloc_bucket_exact, 1);
+				if (b == TDB_FREE_BUCKETS - 1)
+					add_stat(tdb, alloc_bucket_max, 1);
 				/* Worked?  Stay using this list. */
 				tdb->flist_off = flist_off;
 				tdb->flist = flist;
@@ -511,6 +529,7 @@ static tdb_off_t get_free(struct tdb_context *tdb,
 		/* Hmm, try next list. */
 		flist_off = next_flist(tdb, flist_off);
 		flist++;
+
 		if (flist_off == 0) {
 			wrapped = true;
 			flist_off = first_flist(tdb);
@@ -594,6 +613,7 @@ static int tdb_expand(struct tdb_context *tdb, tdb_len_t size)
 	/* We need to drop this lock before adding free record. */
 	tdb_unlock_expand(tdb, F_WRLCK);
 
+	add_stat(tdb, expands, 1);
 	return add_free_record(tdb, old_size, wanted);
 }