<snip> > > > > > > > Hi Phil, > > > > > > On Thu, Jul 09, 2020 at 06:10:42PM +0800, Phil Yang wrote: > > > > Use C11 atomic built-ins with explicit ordering instead of > > > > rte_atomic ops which enforce unnecessary barriers on aarch64. > > > > > > > > Signed-off-by: Phil Yang <phil.y...@arm.com> > > > > Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com> > > > > --- > > > > v3: > > > > 1.Fix ABI breakage. > > > > 2.Simplify data type cast. > > > > > > > > v2: > > > > Fix ABI issue: revert the rte_mbuf_ext_shared_info struct refcnt > > > > field to refcnt_atomic. > > > > > > > > lib/librte_mbuf/rte_mbuf.c | 1 - > > > > lib/librte_mbuf/rte_mbuf.h | 19 ++++++++++--------- > > > > lib/librte_mbuf/rte_mbuf_core.h | 2 +- > > > > 3 files changed, 11 insertions(+), 11 deletions(-) > > > > > > <snip> > > > > > > > > /* Reinitialize counter before mbuf freeing. */ diff --git > > > > a/lib/librte_mbuf/rte_mbuf_core.h > > > b/lib/librte_mbuf/rte_mbuf_core.h > > > > index 16600f1..d65d1c8 100644 > > > > --- a/lib/librte_mbuf/rte_mbuf_core.h > > > > +++ b/lib/librte_mbuf/rte_mbuf_core.h > > > > @@ -679,7 +679,7 @@ typedef void > > > (*rte_mbuf_extbuf_free_callback_t)(void *addr, void *opaque); > > > > struct rte_mbuf_ext_shared_info { > > > > rte_mbuf_extbuf_free_callback_t free_cb; /**< Free callback > > > function */ > > > > void *fcb_opaque; /**< Free callback argument */ > > > > -rte_atomic16_t refcnt_atomic; /**< Atomically accessed refcnt */ > > > > +uint16_t refcnt_atomic; /**< Atomically accessed refcnt */ > > > > }; > > > > > > To avoid an API breakage (i.e. currently, an application that accesses > > > to refcnt_atomic expects that its type is rte_atomic16_t), I suggest > > > to do the same than in the mbuf struct: > > > > > > union { > > > rte_atomic16_t refcnt_atomic; > > > uint16_t refcnt; > > > }; > > > > > > I hope the ABI checker won't complain. > > > > > > It will also be better for 20.11 when the deprecated fields will be > > > renamed: the remaining one will be called 'refcnt' in both mbuf and > > > mbuf_ext_shared_info. > Does this need a deprecation notice in 20.08?
Yes. We'd better do that. I will add a notice for it in this patch. Thanks. > > > > > Got it. I agree with you. > > It should work. In my local test machine, the ABI checker happy with this > > approach. > > Once the test is done, I will upstream the new patch. > > > > Appreciate your comments. > > > > Thanks, > > Phil