exit
fi
done
+From 30927520dbae297182990bb21d08762bcc35ce1d Mon Sep 17 00:00:00 2001
+From: Eric Dumazet <edumazet@google.com>
+Date: Wed, 9 Sep 2015 21:55:07 -0700
+Subject: [PATCH] tcp_cubic: better follow cubic curve after idle period
-diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
-index 7a0c800..ec5ebbb 100644
---- a/drivers/net/ethernet/realtek/r8169.c
-+++ b/drivers/net/ethernet/realtek/r8169.c
-@@ -4103,6 +4103,14 @@ rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
- /* Get MAC address */
- for (i = 0; i < ETH_ALEN; i++)
- dev->dev_addr[i] = RTL_R8(MAC0 + i);
-+
-+ if (!is_valid_ether_addr(dev->dev_addr)) {
-+ /* Report it and use a random ethernet address instead */
-+ netdev_err(dev, "Invalid MAC address: %pM\n", dev->dev_addr);
-+ random_ether_addr(dev->dev_addr);
-+ netdev_info(dev, "Using random MAC address: %pM\n",
-+ dev->dev_addr);
-+ }
- memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
-
- SET_ETHTOOL_OPS(dev, &rtl8169_ethtool_ops);
---
-1.7.7.3
+Jana Iyengar found an interesting issue on CUBIC :
+The epoch is only updated/reset initially and when experiencing losses.
+The delta "t" of now - epoch_start can be arbitrary large after app idle
+as well as the bic_target. Consequentially the slope (inverse of
+ca->cnt) would be really large, and eventually ca->cnt would be
+lower-bounded in the end to 2 to have delayed-ACK slow-start behavior.
-commit 6e601a53566d84e1ffd25e7b6fe0b6894ffd79c0
-Author: Mathias Krause <minipli@googlemail.com>
-Date: Sat Feb 23 01:13:47 2013 +0000
+This particularly shows up when slow_start_after_idle is disabled
+as a dangerous cwnd inflation (1.5 x RTT) after few seconds of idle
+time.
- sock_diag: Fix out-of-bounds access to sock_diag_handlers[]
-
- Userland can send a netlink message requesting SOCK_DIAG_BY_FAMILY
- with a family greater or equal then AF_MAX -- the array size of
- sock_diag_handlers[]. The current code does not test for this
- condition therefore is vulnerable to an out-of-bound access opening
- doors for a privilege escalation.
-
- Signed-off-by: Mathias Krause <minipli@googlemail.com>
- Acked-by: Eric Dumazet <edumazet@google.com>
- Signed-off-by: David S. Miller <davem@davemloft.net>
+Jana initial fix was to reset epoch_start if app limited,
+but Neal pointed out it would ask the CUBIC algorithm to recalculate the
+curve so that we again start growing steeply upward from where cwnd is
+now (as CUBIC does just after a loss). Ideally we'd want the cwnd growth
+curve to be the same shape, just shifted later in time by the amount of
+the idle period.
-diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
-index 602cd63..750f44f 100644
---- a/net/core/sock_diag.c
-+++ b/net/core/sock_diag.c
-@@ -121,6 +121,9 @@ static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
- if (nlmsg_len(nlh) < sizeof(*req))
- return -EINVAL;
+Reported-by: Jana Iyengar <jri@google.com>
+Signed-off-by: Eric Dumazet <edumazet@google.com>
+Signed-off-by: Yuchung Cheng <ycheng@google.com>
+Signed-off-by: Neal Cardwell <ncardwell@google.com>
+Cc: Stephen Hemminger <stephen@networkplumber.org>
+Cc: Sangtae Ha <sangtae.ha@gmail.com>
+Cc: Lawrence Brakmo <lawrence@brakmo.org>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ net/ipv4/tcp_cubic.c | 16 ++++++++++++++++
+ 1 file changed, 16 insertions(+)
+
+diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
+index 28011fb1..c6ded6b 100644
+--- a/net/ipv4/tcp_cubic.c
++++ b/net/ipv4/tcp_cubic.c
+@@ -151,6 +151,21 @@ static void bictcp_init(struct sock *sk)
+ tcp_sk(sk)->snd_ssthresh = initial_ssthresh;
+ }
-+ if (req->sdiag_family >= AF_MAX)
-+ return -EINVAL;
++static void bictcp_cwnd_event(struct sock *sk, enum tcp_ca_event event)
++{
++ if (event == CA_EVENT_TX_START) {
++ s32 delta = tcp_time_stamp - tcp_sk(sk)->lsndtime;
++ struct bictcp *ca = inet_csk_ca(sk);
++
++ /* We were application limited (idle) for a while.
++ * Shift epoch_start to keep cwnd growth to cubic curve.
++ */
++ if (ca->epoch_start && delta > 0)
++ ca->epoch_start += delta;
++ return;
++ }
++}
+
- hndl = sock_diag_lock_handler(req->sdiag_family);
- if (hndl == NULL)
- err = -ENOENT;
+ /* calculate the cubic root of x using a table lookup followed by one
+ * Newton-Raphson iteration.
+ * Avg err ~= 0.195%
+@@ -450,6 +465,7 @@ static struct tcp_congestion_ops cubictcp __read_mostly = {
+ .cong_avoid = bictcp_cong_avoid,
+ .set_state = bictcp_state,
+ .undo_cwnd = bictcp_undo_cwnd,
++ .cwnd_event = bictcp_cwnd_event,
+ .pkts_acked = bictcp_acked,
+ .owner = THIS_MODULE,
+ .name = "cubic",
projects / packages / kernel.git / blobdiff