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authorBenjamin LaHaise <benjamin.c.lahaise@intel.com>2006-03-20 21:29:05 -0800
committerDavid S. Miller <davem@davemloft.net>2006-03-20 21:29:05 -0800
commite9df7d7f584666533b1bdfcf5c60a43d64689198 (patch)
tree78faaa085edfb24784e40779864d41fd9ddeb168 /net/unix
parent231d06ae826664b83369166449144304859a62fa (diff)
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[AF_UNIX]: use shift instead of integer division
The patch below replaces a divide by 2 with a shift -- sk_sndbuf is an integer, so gcc emits an idiv, which takes 10x longer than a shift by 1. This improves af_unix bandwidth by ~6-10K/s. Also, tidy up the comment to fit in 80 columns while we're at it. Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/unix')
-rw-r--r--net/unix/af_unix.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index c323cc6a28b0..2b00460f2886 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1427,15 +1427,15 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
while(sent < len)
{
/*
- * Optimisation for the fact that under 0.01% of X messages typically
- * need breaking up.
+ * Optimisation for the fact that under 0.01% of X
+ * messages typically need breaking up.
*/
- size=len-sent;
+ size = len-sent;
/* Keep two messages in the pipe so it schedules better */
- if (size > sk->sk_sndbuf / 2 - 64)
- size = sk->sk_sndbuf / 2 - 64;
+ if (size > ((sk->sk_sndbuf >> 1) - 64))
+ size = (sk->sk_sndbuf >> 1) - 64;
if (size > SKB_MAX_ALLOC)
size = SKB_MAX_ALLOC;