From: Stephen Hemminger <shemminger@vyatta•com>
To: davem@davemloft•net, sangtae.ha@gmail•com, rhee@ncsu•edu
Cc: netdev@vger•kernel.org
Subject: [PATCH 6/6] tcp_cubic: enable high resolution ack time if needed
Date: Thu, 10 Mar 2011 08:51:28 -0800 [thread overview]
Message-ID: <20110310165329.281291096@vyatta.com> (raw)
In-Reply-To: 20110310165119.224046957@vyatta.com
[-- Attachment #1: tcp-cubic-rtt-cong.patch --]
[-- Type: text/plain, Size: 673 bytes --]
This is a refined version of an earlier patch by Lucas Nussbaum.
Cubic needs RTT values in milliseconds. If HZ < 1000 then
the values will be too coarse.
Signed-off-by: Stephen Hemminger <shemminger@vyatta•com>
--- a/net/ipv4/tcp_cubic.c 2011-03-10 08:35:59.968882888 -0800
+++ b/net/ipv4/tcp_cubic.c 2011-03-10 08:36:10.241016524 -0800
@@ -459,6 +459,10 @@ static int __init cubictcp_register(void
/* divide by bic_scale and by constant Srtt (100ms) */
do_div(cube_factor, bic_scale * 10);
+ /* hystart needs ms clock resolution */
+ if (hystart && HZ < 1000)
+ cubictcp.flags |= TCP_CONG_RTT_STAMP;
+
return tcp_register_congestion_control(&cubictcp);
}
next prev parent reply other threads:[~2011-03-10 16:56 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-10 16:51 [PATCH 0/6] TCP CUBIC and Hystart Stephen Hemminger
2011-03-10 16:51 ` [PATCH 1/6] tcp: fix RTT for quick packets in congestion control Stephen Hemminger
2011-03-10 16:51 ` [PATCH 2/6] tcp: timestamp code clarification Stephen Hemminger
2011-03-10 16:51 ` [PATCH 3/6] tcp_cubic: fix comparison of jiffies Stephen Hemminger
2011-03-11 9:40 ` Lucas Nussbaum
2011-03-10 16:51 ` [PATCH 4/6] tcp_cubic: make ack train delta value a parameter Stephen Hemminger
2011-03-10 16:51 ` [PATCH 5/6] tcp_cubic: fix clock dependency Stephen Hemminger
2011-03-11 16:26 ` Sangtae Ha
2011-03-10 16:51 ` Stephen Hemminger [this message]
2011-03-11 10:28 ` [PATCH 0/6] TCP CUBIC and Hystart Lucas Nussbaum
2011-03-11 10:49 ` Injong Rhee
2011-03-11 15:58 ` Sangtae Ha
2011-03-11 16:08 ` Lucas Nussbaum
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