[dpdk-dev v1] net/sxe2: replace private mempool cache bypass with rte_mbuf_raw_free_bulk

[Kai Ji]

The AVX-512 TX completion path directly manipulated the mempool cache
internals (cache->objs, cache->len, cache->flushthresh) instead of using
the mempool API.  This pattern is the same private bypass that existed in
the Intel common TX library before it was removed by commit 062d6fe5d0e4
("net/intel: do not bypass mbuf lib for buffer fast-free") for the same
reason: it omits mbuf instrumentation (history marking) and contains
dead flush code that accesses cache->objs[cache->size], which is one
past the end of the array when cache_size == RTE_MEMPOOL_CACHE_MAX_SIZE.

Replace with a single rte_mbuf_raw_free_bulk() call, matching the Intel
common library.  The MBUF_FAST_FREE offload guarantee (single pool,
refcnt == 1) makes this correct and the compiler inlines the bulk-free
call to eliminate the overhead difference.

Signed-off-by: Kai Ji <kai...@intel.com>
---
 drivers/net/sxe2/sxe2_txrx_vec_avx512.c | 37 ++-----------------------
 1 file changed, 3 insertions(+), 34 deletions(-)

diff --git a/drivers/net/sxe2/sxe2_txrx_vec_avx512.c 
b/drivers/net/sxe2/sxe2_txrx_vec_avx512.c
index a830c7a33b..9f992a9ddf 100644
--- a/drivers/net/sxe2/sxe2_txrx_vec_avx512.c
+++ b/drivers/net/sxe2/sxe2_txrx_vec_avx512.c
@@ -18,9 +18,6 @@ static __rte_always_inline int32_t 
sxe2_tx_bufs_free_vec_avx512(struct sxe2_tx_q
        struct rte_mbuf *mbuf;
        struct rte_mbuf *mbuf_free_arr[SXE2_TX_FREE_BUFFER_SIZE_MAX_VEC];
        struct rte_mempool *mp;
-       struct rte_mempool_cache *cache;
-       void **cache_objs;
-       uint32_t copied;
        uint32_t i;
        int32_t ret;
        uint16_t rs_thresh;
@@ -41,37 +38,9 @@ static __rte_always_inline int32_t 
sxe2_tx_bufs_free_vec_avx512(struct sxe2_tx_q
        if ((txq->offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE) &&
                        (rs_thresh & 31) == 0) {
                mp = buffer[0].mbuf->pool;
-               cache = rte_mempool_default_cache(mp, rte_lcore_id());
-
-               if (cache == NULL || cache->len)
-                       goto normal;
-
-               if (rs_thresh > RTE_MEMPOOL_CACHE_MAX_SIZE) {
-                       (void)rte_mempool_ops_enqueue_bulk(mp, (void *)buffer, 
rs_thresh);
-                       goto done;
-               }
-               cache_objs = &cache->objs[cache->len];
-
-               copied = 0;
-               while (copied < rs_thresh) {
-                       const __m512i objs0 = 
_mm512_loadu_si512(&buffer[copied]);
-                       const __m512i objs1 = _mm512_loadu_si512(&buffer[copied 
+ 8]);
-                       const __m512i objs2 = _mm512_loadu_si512(&buffer[copied 
+ 16]);
-                       const __m512i objs3 = _mm512_loadu_si512(&buffer[copied 
+ 24]);
-
-                       _mm512_storeu_si512(&cache_objs[copied], objs0);
-                       _mm512_storeu_si512(&cache_objs[copied + 8], objs1);
-                       _mm512_storeu_si512(&cache_objs[copied + 16], objs2);
-                       _mm512_storeu_si512(&cache_objs[copied + 24], objs3);
-                       copied += 32;
-               }
-               cache->len += rs_thresh;
-
-               if (cache->len >= cache->flushthresh) {
-                       (void)rte_mempool_ops_enqueue_bulk(mp,
-                                       &cache->objs[cache->size], cache->len - 
cache->size);
-                       cache->len = cache->size;
-               }
+               static_assert(sizeof(buffer[0]) == sizeof(struct rte_mbuf *),
+                       "sxe2_tx_buffer_vec must be pointer-sized for bulk free 
cast");
+               rte_mbuf_raw_free_bulk(mp, (void *)buffer, rs_thresh);
                goto done;
        }
 
-- 
2.43.0