Hi Morten, > Added cache guard after the table holding the ring elements, to avoid > false sharing conflicts caused by next-line hardware prefetchers when > accessing elements at the end of the ring table.
I don't see any harm with it, and in theory it might help in some cases... Though I wonder how real is that problem? Did you ever observe such contention to happen? > Signed-off-by: Morten Brørup <[email protected]> > --- > lib/ring/rte_ring.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/lib/ring/rte_ring.c b/lib/ring/rte_ring.c > index f10050a1c4..9ccc62cd42 100644 > --- a/lib/ring/rte_ring.c > +++ b/lib/ring/rte_ring.c > @@ -73,8 +73,11 @@ rte_ring_get_memsize_elem(unsigned int esize, unsigned > int count) > return -EINVAL; > } > > + static_assert(sizeof(struct rte_ring) == > RTE_CACHE_LINE_ROUNDUP(sizeof(struct rte_ring)), > + "Size of struct rte_ring not cache line aligned"); > sz = sizeof(struct rte_ring) + (ssize_t)count * esize; > sz = RTE_ALIGN(sz, RTE_CACHE_LINE_SIZE); > + sz += RTE_CACHE_GUARD_LINES * RTE_CACHE_LINE_SIZE; > return sz; > } > > -- > 2.43.0
