On 05/14/2018 12:54 AM, Thomas Monjalon wrote:
12/05/2018 03:59, Andy Green:@@ -836,8 +836,9 @@ rte_mbuf_refcnt_update(struct rte_mbuf *m, int16_t value) * reference counter can occur. */ if (likely(rte_mbuf_refcnt_read(m) == 1)) { - rte_mbuf_refcnt_set(m, 1 + value); - return 1 + value; + ++value; + rte_mbuf_refcnt_set(m, value); + return value; }I don't understand what it is fixing. Please could you explain or show the GCC warning?
"1 + value", where value is an uint16_t causes promotion to a signed int. The compiler complained that we are shoving an int into a uint16_t return type with different size and sign.
Bumping and returning value directly instead removes the promotion and the problem.
I added this explanation to the patch (although the title gave a big clue already).
-Andy
