diff options
| author | Eric Dumazet <edumazet@google.com> | 2020-03-24 19:23:21 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-05-02 08:49:00 +0200 |
| commit | f1610480602a475323f9c335540d47b3a95c62fd (patch) | |
| tree | a61b7aa1c985ac43bc9c7f6d22e7cd3775a9beb4 /net/core | |
| parent | ec9cf8afcd641263bac73a608440a2b22e026a0c (diff) | |
net: use indirect call wrappers for skb_copy_datagram_iter()
commit 29f3490ba9d2399d3d1b20c4aa74592d92bd4e11 upstream.
TCP recvmsg() calls skb_copy_datagram_iter(), which
calls an indirect function (cb pointing to simple_copy_to_iter())
for every MSS (fragment) present in the skb.
CONFIG_RETPOLINE=y forces a very expensive operation
that we can avoid thanks to indirect call wrappers.
This patch gives a 13% increase of performance on
a single flow, if the bottleneck is the thread reading
the TCP socket.
Fixes: 950fcaecd5cc ("datagram: consolidate datagram copy to iter helpers")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/datagram.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c index da3c24ed129c..189ad4c73a3f 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -51,6 +51,7 @@ #include <linux/slab.h> #include <linux/pagemap.h> #include <linux/uio.h> +#include <linux/indirect_call_wrapper.h> #include <net/protocol.h> #include <linux/skbuff.h> @@ -407,6 +408,11 @@ int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags) } EXPORT_SYMBOL(skb_kill_datagram); +INDIRECT_CALLABLE_DECLARE(static size_t simple_copy_to_iter(const void *addr, + size_t bytes, + void *data __always_unused, + struct iov_iter *i)); + static int __skb_datagram_iter(const struct sk_buff *skb, int offset, struct iov_iter *to, int len, bool fault_short, size_t (*cb)(const void *, size_t, void *, @@ -420,7 +426,8 @@ static int __skb_datagram_iter(const struct sk_buff *skb, int offset, if (copy > 0) { if (copy > len) copy = len; - n = cb(skb->data + offset, copy, data, to); + n = INDIRECT_CALL_1(cb, simple_copy_to_iter, + skb->data + offset, copy, data, to); offset += n; if (n != copy) goto short_copy; @@ -442,8 +449,9 @@ static int __skb_datagram_iter(const struct sk_buff *skb, int offset, if (copy > len) copy = len; - n = cb(vaddr + skb_frag_off(frag) + offset - start, - copy, data, to); + n = INDIRECT_CALL_1(cb, simple_copy_to_iter, + vaddr + skb_frag_off(frag) + offset - start, + copy, data, to); kunmap(page); offset += n; if (n != copy) |