net: mvneta: avoid possible cache misses in mvneta_rx_swbm

Do not use rx_desc pointers if possible since rx descriptors are stored in
uncached memory and dereferencing rx_desc pointers generate extra loads.
This patch improves XDP_DROP performance of ~ 110Kpps (700Kpps vs 590Kpps)
on Marvell Espressobin

Analyzed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Lorenzo Bianconi 2020-09-29 23:58:57 +02:00 committed by David S. Miller
parent 2b2706aaae
commit 879456bedb
1 changed files with 6 additions and 6 deletions

View File

@ -2236,19 +2236,22 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp,
enum dma_data_direction dma_dir;
struct skb_shared_info *sinfo;
if (rx_desc->data_size > MVNETA_MAX_RX_BUF_SIZE) {
if (*size > MVNETA_MAX_RX_BUF_SIZE) {
len = MVNETA_MAX_RX_BUF_SIZE;
data_len += len;
} else {
len = rx_desc->data_size;
len = *size;
data_len += len - ETH_FCS_LEN;
}
*size = *size - len;
dma_dir = page_pool_get_dma_dir(rxq->page_pool);
dma_sync_single_for_cpu(dev->dev.parent,
rx_desc->buf_phys_addr,
len, dma_dir);
rx_desc->buf_phys_addr = 0;
/* Prefetch header */
prefetch(data);
@ -2259,9 +2262,6 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp,
sinfo = xdp_get_shared_info_from_buff(xdp);
sinfo->nr_frags = 0;
*size = rx_desc->data_size - len;
rx_desc->buf_phys_addr = 0;
}
static void
@ -2375,7 +2375,7 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
size = rx_desc->data_size;
frame_sz = size - ETH_FCS_LEN;
desc_status = rx_desc->status;
desc_status = rx_status;
mvneta_swbm_rx_frame(pp, rx_desc, rxq, &xdp_buf,
&size, page);