| Message ID | 152609037755.121661.8441874507300238825.stgit@localhost.localdomain (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Thomas Monjalon |
| Headers | show |
| Context | Check | Description |
|---|---|---|
| ci/checkpatch | success | coding style OK |
| ci/Intel-compilation | success | Compilation OK |
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?
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 >
diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index 4fd9a0d9e..a2a37a311 100644 --- a/lib/librte_mbuf/rte_mbuf.h +++ b/lib/librte_mbuf/rte_mbuf.h @@ -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; } return __rte_mbuf_refcnt_update(m, value); @@ -927,8 +928,9 @@ rte_mbuf_ext_refcnt_update(struct rte_mbuf_ext_shared_info *shinfo, int16_t value) { if (likely(rte_mbuf_ext_refcnt_read(shinfo) == 1)) { - rte_mbuf_ext_refcnt_set(shinfo, 1 + value); - return 1 + value; + ++value; + rte_mbuf_ext_refcnt_set(shinfo, value); + return value; } return (uint16_t)rte_atomic16_add_return(&shinfo->refcnt_atomic, value);
Signed-off-by: Andy Green <andy@warmcat.com> --- lib/librte_mbuf/rte_mbuf.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)