gve: DQO: Remove incorrect prefetch
authorBailey Forrest <bcf@google.com>
Fri, 2 Jul 2021 03:13:36 +0000 (20:13 -0700)
committerDavid S. Miller <davem@davemloft.net>
Fri, 2 Jul 2021 19:06:17 +0000 (12:06 -0700)
The prefetch is incorrectly using the dma address instead of the virtual
address.

It's supposed to be:
prefetch((char *)buf_state->page_info.page_address +
 buf_state->page_info.page_offset)

However, after correcting this mistake, there is no evidence of
performance improvement.

Fixes: 9b8dd5e5ea48 ("gve: DQO: Add RX path")
Signed-off-by: Bailey Forrest <bcf@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/google/gve/gve_rx_dqo.c

index 77bb822..8500621 100644 (file)
@@ -566,13 +566,6 @@ static int gve_rx_dqo(struct napi_struct *napi, struct gve_rx_ring *rx,
                return 0;
        }
 
-       /* Prefetch the payload header. */
-       prefetch((char *)buf_state->addr + buf_state->page_info.page_offset);
-#if L1_CACHE_BYTES < 128
-       prefetch((char *)buf_state->addr + buf_state->page_info.page_offset +
-                L1_CACHE_BYTES);
-#endif
-
        if (eop && buf_len <= priv->rx_copybreak) {
                rx->skb_head = gve_rx_copy(priv->dev, napi,
                                           &buf_state->page_info, buf_len, 0);