net: attempt high order allocations in sock_alloc_send_pskb()

Adding paged frags skbs to af_unix sockets introduced a performance
regression on large sends because of additional page allocations, even
if each skb could carry at least 100% more payload than before.

We can instruct sock_alloc_send_pskb() to attempt high order
allocations.

Most of the time, it does a single page allocation instead of 8.

I added an additional parameter to sock_alloc_send_pskb() to
let other users to opt-in for this new feature on followup patches.

Tested:

Before patch :

$ netperf -t STREAM_STREAM
STREAM STREAM TEST
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 2304  212992  212992    10.00    46861.15

After patch :

$ netperf -t STREAM_STREAM
STREAM STREAM TEST
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 2304  212992  212992    10.00    57981.11

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2013-08-08 14:38:47 -07:00
committed by David S. Miller
parent e370a72363
commit 28d6427109
6 changed files with 61 additions and 56 deletions

View File

@@ -1479,7 +1479,8 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
MAX_SKB_FRAGS * PAGE_SIZE);
skb = sock_alloc_send_pskb(sk, len - data_len, data_len,
msg->msg_flags & MSG_DONTWAIT, &err);
msg->msg_flags & MSG_DONTWAIT, &err,
PAGE_ALLOC_COSTLY_ORDER);
if (skb == NULL)
goto out;
@@ -1651,7 +1652,8 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
data_len = max_t(int, 0, size - SKB_MAX_HEAD(0));
skb = sock_alloc_send_pskb(sk, size - data_len, data_len,
msg->msg_flags & MSG_DONTWAIT, &err);
msg->msg_flags & MSG_DONTWAIT, &err,
get_order(UNIX_SKB_FRAGS_SZ));
if (!skb)
goto out_err;