tcp: tcp_sendmsg() page recycling
If our TCP_PAGE(sk) is not shared (page_count() == 1), we can set page
offset to 0.
This permits better filling of the pages on small to medium tcp writes.
"tbench 16" results on my dev server (2x4x2 machine) :
Before : 3072 MB/s
After : 3146 MB/s (2.4 % gain)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 45156be..a09fe25 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1009,7 +1009,12 @@
int merge = 0;
int i = skb_shinfo(skb)->nr_frags;
struct page *page = TCP_PAGE(sk);
- int off = TCP_OFF(sk);
+ int off;
+
+ if (page && page_count(page) == 1)
+ TCP_OFF(sk) = 0;
+
+ off = TCP_OFF(sk);
if (skb_can_coalesce(skb, i, page, off) &&
off != PAGE_SIZE) {