REDIS_ENCODING_EMBSTR_SIZE_LIMIT set to 39.

The new value is the limit for the robj + SDS header + string +
null-term to stay inside the 64 bytes Jemalloc arena in 64 bits
systems.

1 files changed, 5 insertions, 2 deletions

diff --git a/src/object.c b/src/object.c
index 5602b688e..46f1f3f8b 100644
--- a/src/object.c
+++ b/src/object.c
@@ -76,8 +76,11 @@ robj *createEmbeddedStringObject(char *ptr, size_t len) {
 
 /* Create a string object with EMBSTR encoding if it is smaller than
  * REIDS_ENCODING_EMBSTR_SIZE_LIMIT, otherwise the RAW encoding is
- * used. */
-#define REDIS_ENCODING_EMBSTR_SIZE_LIMIT 32
+ * used.
+ *
+ * The current limit of 39 is chosen so that the biggest string object
+ * we allocate as EMBSTR will still fit into the 64 byte arena of jemalloc. */
+#define REDIS_ENCODING_EMBSTR_SIZE_LIMIT 39
 robj *createStringObject(char *ptr, size_t len) {
     if (len <= REDIS_ENCODING_EMBSTR_SIZE_LIMIT)
         return createEmbeddedStringObject(ptr,len);