Re: [PATCH net-next 1/4] dpaa_eth: fix SG mapping
From: David Miller <davem@davemloft.net>
Date: 2018-02-20 18:56:19
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From: Madalin Bucur <madalin.bucur@nxp.com> Date: Mon, 19 Feb 2018 10:10:41 -0600
An issue in the code mapping the skb fragments into scatter-gather frames was evidentiated by netperf TCP_SENDFILE tests. This patch addresses the issue. Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>
This is a poorly worded commit message. You have to say exactly what "the issue" is. Reading your patch:
quoted hunk ↗ jump to hunk
@@ -1916,8 +1916,10 @@ static int skb_to_sg_fd(struct dpaa_priv *priv, goto csum_failed; } + /* SGT[0] is used by the linear part */ sgt = (struct qm_sg_entry *)(sgt_buf + priv->tx_headroom); - qm_sg_entry_set_len(&sgt[0], skb_headlen(skb)); + buff_len = skb_headlen(skb); + qm_sg_entry_set_len(&sgt[0], buff_len); sgt[0].bpid = FSL_DPAA_BPID_INV; sgt[0].offset = 0; addr = dma_map_single(dev, skb->data,
This change has no effect and is unrelated. Please do not mix unrelated changes with the main change, because this makes it hard to review your work.
quoted hunk ↗ jump to hunk
@@ -1930,27 +1932,28 @@ static int skb_to_sg_fd(struct dpaa_priv *priv, qm_sg_entry_set64(&sgt[0], addr); /* populate the rest of SGT entries */ - frag = &skb_shinfo(skb)->frags[0]; - frag_len = frag->size; - for (i = 1; i <= nr_frags; i++, frag++) { + for (i = 0; i < nr_frags; i++) { + frag = &skb_shinfo(skb)->frags[i]; + buff_len = frag->size; WARN_ON(!skb_frag_page(frag)); addr = skb_frag_dma_map(dev, frag, 0, - frag_len, dma_dir); + buff_len, dma_dir);
And clearly the bug you are fixing is simply that frag_len was only being set for the first fragment. Please just fix that bug and remove all of these other completely unrelated changes.