* [PATCH net-next 1/2] selftests: mptcp: add option to specify size of file to transfer
2020-06-30 19:24 [PATCH net-next 0/2] mptcp: add receive buffer auto-tuning Florian Westphal
@ 2020-06-30 19:24 ` Florian Westphal
2020-07-01 13:06 ` Matthieu Baerts
2020-06-30 19:24 ` [PATCH net-next 2/2] mptcp: add receive buffer auto-tuning Florian Westphal
2020-07-02 0:48 ` [PATCH net-next 0/2] " David Miller
2 siblings, 1 reply; 6+ messages in thread
From: Florian Westphal @ 2020-06-30 19:24 UTC (permalink / raw)
To: netdev; +Cc: mptcp, Florian Westphal
The script generates two random files that are then sent via tcp and
mptcp connections.
In order to compare throughput over consecutive runs add an option
to provide the file size on the command line: "-f 128000".
Also add an option, -t, to enable tcp tests. This is useful to
compare throughput of mptcp connections and tcp connections.
Example: run tests with a 4mb file size, 300ms delay 0.01% loss,
default gso/tso/gro settings and with large write/blocking io:
mptcp_connect.sh -t -f $((4 * 1024 * 1024)) -d 300 -l 0.01% -r 0 -e "" -m mmap
Signed-off-by: Florian Westphal <fw@strlen.de>
---
.../selftests/net/mptcp/mptcp_connect.sh | 52 ++++++++++++++-----
1 file changed, 39 insertions(+), 13 deletions(-)
diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.sh b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
index acf02e156d20..8f7145c413b9 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
@@ -3,7 +3,7 @@
time_start=$(date +%s)
-optstring="S:R:d:e:l:r:h4cm:"
+optstring="S:R:d:e:l:r:h4cm:f:t"
ret=0
sin=""
sout=""
@@ -21,6 +21,8 @@ testmode=""
sndbuf=0
rcvbuf=0
options_log=true
+do_tcp=0
+filesize=0
if [ $tc_loss -eq 100 ];then
tc_loss=1%
@@ -40,9 +42,11 @@ usage() {
echo -e "\t-e: ethtool features to disable, e.g.: \"-e tso -e gso\" (default: randomly disable any of tso/gso/gro)"
echo -e "\t-4: IPv4 only: disable IPv6 tests (default: test both IPv4 and IPv6)"
echo -e "\t-c: capture packets for each test using tcpdump (default: no capture)"
+ echo -e "\t-f: size of file to transfer in bytes (default random)"
echo -e "\t-S: set sndbuf value (default: use kernel default)"
echo -e "\t-R: set rcvbuf value (default: use kernel default)"
echo -e "\t-m: test mode (poll, sendfile; default: poll)"
+ echo -e "\t-t: also run tests with TCP (use twice to non-fallback tcp)"
}
while getopts "$optstring" option;do
@@ -94,6 +98,12 @@ while getopts "$optstring" option;do
"m")
testmode="$OPTARG"
;;
+ "f")
+ filesize="$OPTARG"
+ ;;
+ "t")
+ do_tcp=$((do_tcp+1))
+ ;;
"?")
usage $0
exit 1
@@ -449,20 +459,25 @@ make_file()
{
local name=$1
local who=$2
+ local SIZE=$filesize
+ local ksize
+ local rem
- local SIZE TSIZE
- SIZE=$((RANDOM % (1024 * 8)))
- TSIZE=$((SIZE * 1024))
+ if [ $SIZE -eq 0 ]; then
+ local MAXSIZE=$((1024 * 1024 * 8))
+ local MINSIZE=$((1024 * 256))
- dd if=/dev/urandom of="$name" bs=1024 count=$SIZE 2> /dev/null
+ SIZE=$(((RANDOM * RANDOM + MINSIZE) % MAXSIZE))
+ fi
- SIZE=$((RANDOM % 1024))
- SIZE=$((SIZE + 128))
- TSIZE=$((TSIZE + SIZE))
- dd if=/dev/urandom conv=notrunc of="$name" bs=1 count=$SIZE 2> /dev/null
+ ksize=$((SIZE / 1024))
+ rem=$((SIZE - (ksize * 1024)))
+
+ dd if=/dev/urandom of="$name" bs=1024 count=$ksize 2> /dev/null
+ dd if=/dev/urandom conv=notrunc of="$name" bs=1 count=$rem 2> /dev/null
echo -e "\nMPTCP_TEST_FILE_END_MARKER" >> "$name"
- echo "Created $name (size $TSIZE) containing data sent by $who"
+ echo "Created $name (size $(du -b "$name")) containing data sent by $who"
}
run_tests_lo()
@@ -497,9 +512,11 @@ run_tests_lo()
return 1
fi
- # don't bother testing fallback tcp except for loopback case.
- if [ ${listener_ns} != ${connector_ns} ]; then
- return 0
+ if [ $do_tcp -eq 0 ]; then
+ # don't bother testing fallback tcp except for loopback case.
+ if [ ${listener_ns} != ${connector_ns} ]; then
+ return 0
+ fi
fi
do_transfer ${listener_ns} ${connector_ns} MPTCP TCP ${connect_addr} ${local_addr}
@@ -516,6 +533,15 @@ run_tests_lo()
return 1
fi
+ if [ $do_tcp -gt 1 ] ;then
+ do_transfer ${listener_ns} ${connector_ns} TCP TCP ${connect_addr} ${local_addr}
+ lret=$?
+ if [ $lret -ne 0 ]; then
+ ret=$lret
+ return 1
+ fi
+ fi
+
return 0
}
--
2.26.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH net-next 2/2] mptcp: add receive buffer auto-tuning
2020-06-30 19:24 [PATCH net-next 0/2] mptcp: add receive buffer auto-tuning Florian Westphal
2020-06-30 19:24 ` [PATCH net-next 1/2] selftests: mptcp: add option to specify size of file to transfer Florian Westphal
@ 2020-06-30 19:24 ` Florian Westphal
2020-07-01 13:07 ` Matthieu Baerts
2020-07-02 0:48 ` [PATCH net-next 0/2] " David Miller
2 siblings, 1 reply; 6+ messages in thread
From: Florian Westphal @ 2020-06-30 19:24 UTC (permalink / raw)
To: netdev; +Cc: mptcp, Florian Westphal
When mptcp is used, userspace doesn't read from the tcp (subflow)
socket but from the parent (mptcp) socket receive queue.
skbs are moved from the subflow socket to the mptcp rx queue either from
'data_ready' callback (if mptcp socket can be locked), a work queue, or
the socket receive function.
This means tcp_rcv_space_adjust() is never called and thus no receive
buffer size auto-tuning is done.
An earlier (not merged) patch added tcp_rcv_space_adjust() calls to the
function that moves skbs from subflow to mptcp socket.
While this enabled autotuning, it also meant tuning was done even if
userspace was reading the mptcp socket very slowly.
This adds mptcp_rcv_space_adjust() and calls it after userspace has
read data from the mptcp socket rx queue.
Its very similar to tcp_rcv_space_adjust, with two differences:
1. The rtt estimate is the largest one observed on a subflow
2. The rcvbuf size and window clamp of all subflows is adjusted
to the mptcp-level rcvbuf.
Otherwise, we get spurious drops at tcp (subflow) socket level if
the skbs are not moved to the mptcp socket fast enough.
Before:
time mptcp_connect.sh -t -f $((4*1024*1024)) -d 300 -l 0.01% -r 0 -e "" -m mmap
[..]
ns4 MPTCP -> ns3 (10.0.3.2:10108 ) MPTCP (duration 40823ms) [ OK ]
ns4 MPTCP -> ns3 (10.0.3.2:10109 ) TCP (duration 23119ms) [ OK ]
ns4 TCP -> ns3 (10.0.3.2:10110 ) MPTCP (duration 5421ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10111) MPTCP (duration 41446ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10112) TCP (duration 23427ms) [ OK ]
ns4 TCP -> ns3 (dead:beef:3::2:10113) MPTCP (duration 5426ms) [ OK ]
Time: 1396 seconds
After:
ns4 MPTCP -> ns3 (10.0.3.2:10108 ) MPTCP (duration 5417ms) [ OK ]
ns4 MPTCP -> ns3 (10.0.3.2:10109 ) TCP (duration 5427ms) [ OK ]
ns4 TCP -> ns3 (10.0.3.2:10110 ) MPTCP (duration 5422ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10111) MPTCP (duration 5415ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10112) TCP (duration 5422ms) [ OK ]
ns4 TCP -> ns3 (dead:beef:3::2:10113) MPTCP (duration 5423ms) [ OK ]
Time: 296 seconds
Signed-off-by: Florian Westphal <fw@strlen.de>
---
net/mptcp/protocol.c | 123 ++++++++++++++++++++++++++++++++++++++++---
net/mptcp/protocol.h | 7 +++
net/mptcp/subflow.c | 5 +-
3 files changed, 127 insertions(+), 8 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 28ec26d97f96..fa137a9c42d1 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -179,13 +179,6 @@ static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
return false;
}
- if (!(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
- int rcvbuf = max(ssk->sk_rcvbuf, sk->sk_rcvbuf);
-
- if (rcvbuf > sk->sk_rcvbuf)
- sk->sk_rcvbuf = rcvbuf;
- }
-
tp = tcp_sk(ssk);
do {
u32 map_remaining, offset;
@@ -916,6 +909,100 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk,
return copied;
}
+/* receive buffer autotuning. See tcp_rcv_space_adjust for more information.
+ *
+ * Only difference: Use highest rtt estimate of the subflows in use.
+ */
+static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied)
+{
+ struct mptcp_subflow_context *subflow;
+ struct sock *sk = (struct sock *)msk;
+ u32 time, advmss = 1;
+ u64 rtt_us, mstamp;
+
+ sock_owned_by_me(sk);
+
+ if (copied <= 0)
+ return;
+
+ msk->rcvq_space.copied += copied;
+
+ mstamp = div_u64(tcp_clock_ns(), NSEC_PER_USEC);
+ time = tcp_stamp_us_delta(mstamp, msk->rcvq_space.time);
+
+ rtt_us = msk->rcvq_space.rtt_us;
+ if (rtt_us && time < (rtt_us >> 3))
+ return;
+
+ rtt_us = 0;
+ mptcp_for_each_subflow(msk, subflow) {
+ const struct tcp_sock *tp;
+ u64 sf_rtt_us;
+ u32 sf_advmss;
+
+ tp = tcp_sk(mptcp_subflow_tcp_sock(subflow));
+
+ sf_rtt_us = READ_ONCE(tp->rcv_rtt_est.rtt_us);
+ sf_advmss = READ_ONCE(tp->advmss);
+
+ rtt_us = max(sf_rtt_us, rtt_us);
+ advmss = max(sf_advmss, advmss);
+ }
+
+ msk->rcvq_space.rtt_us = rtt_us;
+ if (time < (rtt_us >> 3) || rtt_us == 0)
+ return;
+
+ if (msk->rcvq_space.copied <= msk->rcvq_space.space)
+ goto new_measure;
+
+ if (sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf &&
+ !(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
+ int rcvmem, rcvbuf;
+ u64 rcvwin, grow;
+
+ rcvwin = ((u64)msk->rcvq_space.copied << 1) + 16 * advmss;
+
+ grow = rcvwin * (msk->rcvq_space.copied - msk->rcvq_space.space);
+
+ do_div(grow, msk->rcvq_space.space);
+ rcvwin += (grow << 1);
+
+ rcvmem = SKB_TRUESIZE(advmss + MAX_TCP_HEADER);
+ while (tcp_win_from_space(sk, rcvmem) < advmss)
+ rcvmem += 128;
+
+ do_div(rcvwin, advmss);
+ rcvbuf = min_t(u64, rcvwin * rcvmem,
+ sock_net(sk)->ipv4.sysctl_tcp_rmem[2]);
+
+ if (rcvbuf > sk->sk_rcvbuf) {
+ u32 window_clamp;
+
+ window_clamp = tcp_win_from_space(sk, rcvbuf);
+ WRITE_ONCE(sk->sk_rcvbuf, rcvbuf);
+
+ /* Make subflows follow along. If we do not do this, we
+ * get drops at subflow level if skbs can't be moved to
+ * the mptcp rx queue fast enough (announced rcv_win can
+ * exceed ssk->sk_rcvbuf).
+ */
+ mptcp_for_each_subflow(msk, subflow) {
+ struct sock *ssk;
+
+ ssk = mptcp_subflow_tcp_sock(subflow);
+ WRITE_ONCE(ssk->sk_rcvbuf, rcvbuf);
+ tcp_sk(ssk)->window_clamp = window_clamp;
+ }
+ }
+ }
+
+ msk->rcvq_space.space = msk->rcvq_space.copied;
+new_measure:
+ msk->rcvq_space.copied = 0;
+ msk->rcvq_space.time = mstamp;
+}
+
static bool __mptcp_move_skbs(struct mptcp_sock *msk)
{
unsigned int moved = 0;
@@ -1028,6 +1115,8 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
set_bit(MPTCP_DATA_READY, &msk->flags);
}
out_err:
+ mptcp_rcv_space_adjust(msk, copied);
+
release_sock(sk);
return copied;
}
@@ -1241,6 +1330,7 @@ static int mptcp_init_sock(struct sock *sk)
return ret;
sk_sockets_allocated_inc(sk);
+ sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1];
sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[2];
return 0;
@@ -1423,6 +1513,22 @@ struct sock *mptcp_sk_clone(const struct sock *sk,
return nsk;
}
+void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk)
+{
+ const struct tcp_sock *tp = tcp_sk(ssk);
+
+ msk->rcvq_space.copied = 0;
+ msk->rcvq_space.rtt_us = 0;
+
+ msk->rcvq_space.time = tp->tcp_mstamp;
+
+ /* initial rcv_space offering made to peer */
+ msk->rcvq_space.space = min_t(u32, tp->rcv_wnd,
+ TCP_INIT_CWND * tp->advmss);
+ if (msk->rcvq_space.space == 0)
+ msk->rcvq_space.space = TCP_INIT_CWND * TCP_MSS_DEFAULT;
+}
+
static struct sock *mptcp_accept(struct sock *sk, int flags, int *err,
bool kern)
{
@@ -1471,6 +1577,7 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err,
list_add(&subflow->node, &msk->conn_list);
inet_sk_state_store(newsk, TCP_ESTABLISHED);
+ mptcp_rcv_space_init(msk, ssk);
bh_unlock_sock(new_mptcp_sock);
__MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEPASSIVEACK);
@@ -1631,6 +1738,8 @@ void mptcp_finish_connect(struct sock *ssk)
atomic64_set(&msk->snd_una, msk->write_seq);
mptcp_pm_new_connection(msk, 0);
+
+ mptcp_rcv_space_init(msk, ssk);
}
static void mptcp_sock_graft(struct sock *sk, struct socket *parent)
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 1d05d9841b5c..a6412ff0fddb 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -209,6 +209,12 @@ struct mptcp_sock {
struct socket *subflow; /* outgoing connect/listener/!mp_capable */
struct sock *first;
struct mptcp_pm_data pm;
+ struct {
+ u32 space; /* bytes copied in last measurement window */
+ u32 copied; /* bytes copied in this measurement window */
+ u64 time; /* start time of measurement window */
+ u64 rtt_us; /* last maximum rtt of subflows */
+ } rcvq_space;
};
#define mptcp_for_each_subflow(__msk, __subflow) \
@@ -369,6 +375,7 @@ void mptcp_get_options(const struct sk_buff *skb,
struct mptcp_options_received *mp_opt);
void mptcp_finish_connect(struct sock *sk);
+void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
void mptcp_data_ready(struct sock *sk, struct sock *ssk);
bool mptcp_finish_join(struct sock *sk);
void mptcp_data_acked(struct sock *sk);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 548f9e347ff5..0e65bc07363c 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -253,8 +253,10 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
pr_fallback(mptcp_sk(subflow->conn));
}
- if (mptcp_check_fallback(sk))
+ if (mptcp_check_fallback(sk)) {
+ mptcp_rcv_space_init(mptcp_sk(parent), sk);
return;
+ }
if (subflow->mp_capable) {
pr_debug("subflow=%p, remote_key=%llu", mptcp_subflow_ctx(sk),
@@ -1130,6 +1132,7 @@ static void subflow_state_change(struct sock *sk)
if (subflow_simultaneous_connect(sk)) {
mptcp_do_fallback(sk);
+ mptcp_rcv_space_init(mptcp_sk(parent), sk);
pr_fallback(mptcp_sk(parent));
subflow->conn_finished = 1;
if (inet_sk_state_load(parent) == TCP_SYN_SENT) {
--
2.26.2
^ permalink raw reply related [flat|nested] 6+ messages in thread