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authorKonstantin Khlebnikov <khlebnikov@yandex-team.ru>2017-11-02 17:07:05 +0300
committerDavid S. Miller <davem@davemloft.net>2017-11-04 22:34:52 +0900
commit991a26af2e65e0422b2a899e373c0146f2436cae (patch)
treef4bc9dcd39fd1d3e88d79446f9e7b6e727e074a2 /net/ipv4/tcp_nv.c
parent9d917c207d6b212eb5fb4d8ca31826e5b75b4d28 (diff)
downloadlinux-991a26af2e65e0422b2a899e373c0146f2436cae.tar.bz2
tcp_nv: use do_div() instead of expensive div64_u64()
Average RTT is 32-bit thus full 64-bit division is redundant. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Suggested-by: Stephen Hemminger <stephen@networkplumber.org> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_nv.c')
-rw-r--r--net/ipv4/tcp_nv.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/net/ipv4/tcp_nv.c b/net/ipv4/tcp_nv.c
index 0529e29e2941..0b5a05bd82e3 100644
--- a/net/ipv4/tcp_nv.c
+++ b/net/ipv4/tcp_nv.c
@@ -242,7 +242,7 @@ static void tcpnv_acked(struct sock *sk, const struct ack_sample *sample)
struct tcp_sock *tp = tcp_sk(sk);
struct tcpnv *ca = inet_csk_ca(sk);
unsigned long now = jiffies;
- s64 rate64 = 0;
+ u64 rate64;
u32 rate, max_win, cwnd_by_slope;
u32 avg_rtt;
u32 bytes_acked = 0;
@@ -284,8 +284,9 @@ static void tcpnv_acked(struct sock *sk, const struct ack_sample *sample)
}
/* rate in 100's bits per second */
- rate64 = ((u64)sample->in_flight) * 8000000;
- rate = (u32)div64_u64(rate64, (u64)(avg_rtt ?: 1) * 100);
+ rate64 = ((u64)sample->in_flight) * 80000;
+ do_div(rate64, avg_rtt ?: 1);
+ rate = (u32)rate64;
/* Remember the maximum rate seen during this RTT
* Note: It may be more than one RTT. This function should be