Patchwork tcp: clean up use of jiffies in tcp_rcv_rtt_measure()

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Submitter Neal Cardwell
Date April 27, 2012, 3:29 p.m.
Message ID <1335540577-32554-1-git-send-email-ncardwell@google.com>
Download mbox | patch
Permalink /patch/155523/
State Accepted
Delegated to: David Miller
Headers show

Comments

Neal Cardwell - April 27, 2012, 3:29 p.m.
Clean up a reference to jiffies in tcp_rcv_rtt_measure() that should
instead reference tcp_time_stamp. Since the result of the subtraction
is passed into a function taking u32, this should not change any
behavior (and indeed the generated assembly does not change on
x86_64). However, it seems worth cleaning this up for consistency and
clarity (and perhaps to avoid bugs if this is copied and pasted
somewhere else).

Signed-off-by: Neal Cardwell <ncardwell@google.com>
---
 net/ipv4/tcp_input.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
Eric Dumazet - April 27, 2012, 3:56 p.m.
On Fri, 2012-04-27 at 11:29 -0400, Neal Cardwell wrote:
> Clean up a reference to jiffies in tcp_rcv_rtt_measure() that should
> instead reference tcp_time_stamp. Since the result of the subtraction
> is passed into a function taking u32, this should not change any
> behavior (and indeed the generated assembly does not change on
> x86_64). However, it seems worth cleaning this up for consistency and
> clarity (and perhaps to avoid bugs if this is copied and pasted
> somewhere else).
> 
> Signed-off-by: Neal Cardwell <ncardwell@google.com>
> ---

Acked-by: Eric Dumazet <edumazet@google.com>



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David Miller - April 27, 2012, 4:35 p.m.
From: Neal Cardwell <ncardwell@google.com>
Date: Fri, 27 Apr 2012 11:29:37 -0400

> Clean up a reference to jiffies in tcp_rcv_rtt_measure() that should
> instead reference tcp_time_stamp. Since the result of the subtraction
> is passed into a function taking u32, this should not change any
> behavior (and indeed the generated assembly does not change on
> x86_64). However, it seems worth cleaning this up for consistency and
> clarity (and perhaps to avoid bugs if this is copied and pasted
> somewhere else).
> 
> Signed-off-by: Neal Cardwell <ncardwell@google.com>

Applied, thanks.
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Patch

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 3ff36406..2a702e3 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -495,7 +495,7 @@  static inline void tcp_rcv_rtt_measure(struct tcp_sock *tp)
 		goto new_measure;
 	if (before(tp->rcv_nxt, tp->rcv_rtt_est.seq))
 		return;
-	tcp_rcv_rtt_update(tp, jiffies - tp->rcv_rtt_est.time, 1);
+	tcp_rcv_rtt_update(tp, tcp_time_stamp - tp->rcv_rtt_est.time, 1);
 
 new_measure:
 	tp->rcv_rtt_est.seq = tp->rcv_nxt + tp->rcv_wnd;