[PATCH net-next V3] tun/macvtap: use consume_skb() instead of kfree_skb() when needed

From: Jason Wang
Date: Thu Nov 27 2014 - 01:36:17 EST


To be more friendly with drop monitor, we should only call kfree_skb() when
the packets were dropped and use consume_skb() in other cases.

Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
Changes from V2:
- use unlikely() when necessary
Changes from V1:
- check the return value of tun/macvtap_put_user()
---
drivers/net/macvtap.c | 5 ++++-
drivers/net/tun.c | 5 ++++-
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 42a80d3..86f6bf8 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -862,7 +862,10 @@ static ssize_t macvtap_do_read(struct macvtap_queue *q,
}
iov_iter_init(&iter, READ, iv, segs, len);
ret = macvtap_put_user(q, skb, &iter);
- kfree_skb(skb);
+ if (unlikely(ret < 0))
+ kfree_skb(skb);
+ else
+ consume_skb(skb);
break;
}

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index ac53a73..82a9bf0 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1363,7 +1363,10 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,

iov_iter_init(&iter, READ, iv, segs, len);
ret = tun_put_user(tun, tfile, skb, &iter);
- kfree_skb(skb);
+ if (unlikely(ret < 0))
+ kfree_skb(skb);
+ else
+ consume_skb(skb);

return ret;
}
--
1.9.1

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