[PATCH 17/31] [CCID3]: Use MSS for larger initial windows
From: Gerrit Renker <hidden>
Date: 2007-03-20 23:14:33
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
This improves the slow-start phase by using the MSS
(as suggested in RFC 4342, sec. 5) instead of the packet size s.
Also figured out that __u32 is ample resource enough.
After applying, I got the following in the logs:
ccid3_hc_tx_packet_recv: client(f7421700), s=6, MSS=1424, w_init=4380, R_sample=176us, X=24886363
Had the previous variant been used, w_init would have been as low as 24.
Committer note: removed unneeded cast to unsigned long long that was
causing a compiler warning on 64bit architectures.
Signed-off-by: Gerrit Renker <redacted>
Acked-by: Ian McDonald <redacted>
Signed-off-by: Arnaldo Carvalho de Melo <redacted>
---
net/dccp/ccids/ccid3.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 0009b39..52dae40 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c@@ -466,20 +466,20 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { /* * Larger Initial Windows [RFC 4342, sec. 5] - * We deviate in that we use `s' instead of `MSS'. */ - __u64 w_init = min(4 * hctx->ccid3hctx_s, - max(2 * hctx->ccid3hctx_s, 4380)); + __u32 w_init = min(4 * dp->dccps_mss_cache, + max(2 * dp->dccps_mss_cache, 4380U)); hctx->ccid3hctx_rtt = r_sample; hctx->ccid3hctx_x = scaled_div(w_init << 6, r_sample); hctx->ccid3hctx_t_ld = now; ccid3_update_send_time(hctx); - ccid3_pr_debug("%s(%p), s=%u, w_init=%llu, " + ccid3_pr_debug("%s(%p), s=%u, MSS=%u, w_init=%u, " "R_sample=%dus, X=%u\n", dccp_role(sk), sk, hctx->ccid3hctx_s, - (unsigned long long)w_init, + dp->dccps_mss_cache, + w_init, (int)r_sample, (unsigned)(hctx->ccid3hctx_x >> 6));
--
1.5.0.3