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| author | Pavel Begunkov <asml.silence@gmail.com> | 2022-04-28 12:57:46 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-05-02 23:36:24 +0200 |
| commit | 829b7bdd70449c211eb6b2673fcbc597ce120939 (patch) | |
| tree | b0f32cba453e0e9472cd6d0f76db77c6ef7c2bf2 | |
| parent | octeontx2-af: debugfs: fix error return of allocations (diff) | |
| download | linux-829b7bdd70449c211eb6b2673fcbc597ce120939.tar.xz linux-829b7bdd70449c211eb6b2673fcbc597ce120939.zip | |
tcp: optimise skb_zerocopy_iter_stream()
It's expensive to make a copy of 40B struct iov_iter to the point it
was taking 0.2-0.5% of all cycles in my tests. iov_iter_revert() should
be fine as it's a simple case without nested reverts/truncates.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a7e1690c00c5dfe700c30eb9a8a81ec59f6545dd.1650884401.git.asml.silence@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/core/skbuff.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index b92e93dcaa91..475183f37891 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1344,7 +1344,6 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, struct ubuf_info *uarg) { struct ubuf_info *orig_uarg = skb_zcopy(skb); - struct iov_iter orig_iter = msg->msg_iter; int err, orig_len = skb->len; /* An skb can only point to one uarg. This edge case happens when @@ -1358,7 +1357,7 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, struct sock *save_sk = skb->sk; /* Streams do not free skb on error. Reset to prev state. */ - msg->msg_iter = orig_iter; + iov_iter_revert(&msg->msg_iter, skb->len - orig_len); skb->sk = sk; ___pskb_trim(skb, orig_len); skb->sk = save_sk; |