diff options
author | Eric Dumazet <eric.dumazet@gmail.com> | 2012-04-03 01:28:28 -0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2012-04-03 16:43:18 -0400 |
commit | eb6a24816b247c0be6b2e97e68933072874bbe54 (patch) | |
tree | c815981e955e9e32d1b9bd279bd18a358038e031 /net | |
parent | edbc0bb3fb72ec4645a242520cf1d0b9b6b02261 (diff) |
af_unix: reduce high order page allocations
unix_dgram_sendmsg() currently builds linear skbs, and this can stress
page allocator with high order page allocations. When memory gets
fragmented, this can eventually fail.
We can try to use order-2 allocations for skb head (SKB_MAX_ALLOC) plus
up to 16 page fragments to lower pressure on buddy allocator.
This patch has no effect on messages of less than 16064 bytes.
(on 64bit arches with PAGE_SIZE=4096)
For bigger messages (from 16065 to 81600 bytes), this patch brings
reliability at the expense of performance penalty because of extra pages
allocations.
netperf -t DG_STREAM -T 0,2 -- -m 16064 -s 200000
->4086040 Messages / 10s
netperf -t DG_STREAM -T 0,2 -- -m 16068 -s 200000
->3901747 Messages / 10s
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/unix/af_unix.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index d510353ef431..eadb9020cd64 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c | |||
@@ -1442,6 +1442,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, | |||
1442 | long timeo; | 1442 | long timeo; |
1443 | struct scm_cookie tmp_scm; | 1443 | struct scm_cookie tmp_scm; |
1444 | int max_level; | 1444 | int max_level; |
1445 | int data_len = 0; | ||
1445 | 1446 | ||
1446 | if (NULL == siocb->scm) | 1447 | if (NULL == siocb->scm) |
1447 | siocb->scm = &tmp_scm; | 1448 | siocb->scm = &tmp_scm; |
@@ -1475,7 +1476,13 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, | |||
1475 | if (len > sk->sk_sndbuf - 32) | 1476 | if (len > sk->sk_sndbuf - 32) |
1476 | goto out; | 1477 | goto out; |
1477 | 1478 | ||
1478 | skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); | 1479 | if (len > SKB_MAX_ALLOC) |
1480 | data_len = min_t(size_t, | ||
1481 | len - SKB_MAX_ALLOC, | ||
1482 | MAX_SKB_FRAGS * PAGE_SIZE); | ||
1483 | |||
1484 | skb = sock_alloc_send_pskb(sk, len - data_len, data_len, | ||
1485 | msg->msg_flags & MSG_DONTWAIT, &err); | ||
1479 | if (skb == NULL) | 1486 | if (skb == NULL) |
1480 | goto out; | 1487 | goto out; |
1481 | 1488 | ||
@@ -1485,8 +1492,10 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, | |||
1485 | max_level = err + 1; | 1492 | max_level = err + 1; |
1486 | unix_get_secdata(siocb->scm, skb); | 1493 | unix_get_secdata(siocb->scm, skb); |
1487 | 1494 | ||
1488 | skb_reset_transport_header(skb); | 1495 | skb_put(skb, len - data_len); |
1489 | err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); | 1496 | skb->data_len = data_len; |
1497 | skb->len = len; | ||
1498 | err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, 0, len); | ||
1490 | if (err) | 1499 | if (err) |
1491 | goto out_free; | 1500 | goto out_free; |
1492 | 1501 | ||