Neal Cardwell 7d21d54d62 bpf: tcp: bpf_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT ... Apply the fix from: "tcp_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT" to the BPF implementation of TCP CUBIC congestion control. Repeating the commit description here for completeness: Mirja Kuehlewind reported a bug in Linux TCP CUBIC Hystart, where Hystart HYSTART_DELAY mechanism can exit Slow Start spuriously on an ACK when the minimum rtt of a connection goes down. From inspection it is clear from the existing code that this could happen in an example like the following: o The first 8 RTT samples in a round trip are 150ms, resulting in a curr_rtt of 150ms and a delay_min of 150ms. o The 9th RTT sample is 100ms. The curr_rtt does not change after the first 8 samples, so curr_rtt remains 150ms. But delay_min can be lowered at any time, so delay_min falls to 100ms. The code executes the HYSTART_DELAY comparison between curr_rtt of 150ms and delay_min of 100ms, and the curr_rtt is declared far enough above delay_min to force a (spurious) exit of Slow start. The fix here is simple: allow every RTT sample in a round trip to lower the curr_rtt. Fixes: 6de4a9c430 ("bpf: tcp: Add bpf_cubic example") Reported-by: Mirja Kuehlewind <mirja.kuehlewind@ericsson.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2020-06-25 16:08:47 -07:00
..
android	SPDX patches for 5.7-rc1.	2020-04-03 13:12:26 -07:00
arm64	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
bpf	bpf: tcp: bpf_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT	2020-06-25 16:08:47 -07:00
breakpoints	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
capabilities	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
cgroup	SPDX patches for 5.7-rc1.	2020-04-03 13:12:26 -07:00
clone3	SPDX patches for 5.7-rc1.	2020-04-03 13:12:26 -07:00
cpu-hotplug
cpufreq
dmabuf-heaps	kselftests: dmabuf-heaps: Fix confused return value on expected error testing	2020-05-08 09:40:58 -06:00
drivers	selftests: mlxsw: Add test for control packets	2020-06-01 11:49:23 -07:00
efivarfs	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
exec	linux-kselftest-5.8-rc1	2020-06-09 10:03:12 -07:00
filesystems	kselftests: introduce new epoll60 testcase for catching lost wakeups	2020-05-07 19:27:21 -07:00
firmware	selftests: firmware: Add firmware_request_platform tests	2020-03-20 14:54:04 +01:00
ftrace	Tracing updates for 5.8:	2020-06-09 10:06:18 -07:00
futex	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
gpio	selftests: add build/cross-build dependency check script	2020-04-23 17:23:20 -06:00
ia64	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
intel_pstate	selftests: add build/cross-build dependency check script	2020-04-23 17:23:20 -06:00
ipc	selftests/ipc: Fix test failure seen after initial test run	2020-04-14 10:24:28 -06:00
ir	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
kcmp	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
kexec	sefltest/ima: support appended signatures (modsig)	2019-08-29 12:45:30 -04:00
kmod	selftests: kmod: test disabling module autoloading	2020-04-10 15:36:22 -07:00
kselftest	kselftest/runner: allow to properly deliver signals to tests	2020-04-14 09:49:13 -06:00
kvm	KVM: selftests: fix sync_with_host() in smm_test	2020-06-11 12:35:19 -04:00
lib	lib: make a test module with set/clear bit	2020-06-04 19:06:25 -07:00
livepatch	selftests: Install settings files to fix TIMEOUT failures	2020-02-20 08:56:42 -07:00
lkdtm	selftests/lkdtm: Use grep -E instead of egrep	2020-05-08 09:46:17 -06:00
locking
media_tests	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
membarrier	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
memfd	selftests: add build/cross-build dependency check script	2020-04-23 17:23:20 -06:00
memory-hotplug
mount	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
mqueue	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
net	selftests/net: report etf errors correctly	2020-06-19 20:23:02 -07:00
netfilter	selftests: netfilter: add test case for conntrack helper assignment	2020-06-25 00:50:31 +02:00
nsfs	tools/testing: Replace zero-length array with flexible-array	2020-05-08 09:42:14 -06:00
ntb	NTB: ntb_test: Fix bug when counting remote files	2020-06-05 20:02:09 -04:00
openat2	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
pid_namespace	selftests: add pid namespace ENOMEM regression test	2020-03-25 13:50:34 +01:00
pidfd	selftests/pidfd: add pidfd setns tests	2020-05-13 11:41:22 +02:00
powerpc	selftests/powerpc: Add a test of counting larx/stcx	2020-05-15 11:58:55 +10:00
prctl	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
proc	proc: use human-readable values for hidepid	2020-04-22 10:51:22 -05:00
pstore	pstore/platform: Use backend name for console registration	2020-05-30 10:34:02 -07:00
ptp	ptp: Add adjust_phase to ptp_clock_caps capability.	2020-05-02 16:31:45 -07:00
ptrace	SPDX patches for 5.7-rc1.	2020-04-03 13:12:26 -07:00
rcutorture	Merge branches 'fixes.2020.04.27a', 'kfree_rcu.2020.04.27a', 'rcu-tasks.2020.04.27a', 'stall.2020.04.27a' and 'torture.2020.05.07a' into HEAD	2020-05-07 10:18:32 -07:00
resctrl	selftests/resctrl: fix spelling mistake "Errror" -> "Error"	2020-03-13 13:29:22 -06:00
rseq	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
rtc	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
safesetid	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
seccomp	selftests/seccomp: allow clock_nanosleep instead of nanosleep	2020-04-14 09:49:51 -06:00
sigaltstack	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
size	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
sparc64	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
splice	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
static_keys
sync	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
sysctl	linux-kselftest-5.8-rc1	2020-06-09 10:03:12 -07:00
tc-testing	tc-testing: update geneve options match in tunnel_key unit tests	2020-06-20 17:35:18 -07:00
timens	selftests/timens: handle a case when alarm clocks are not supported	2020-05-22 13:29:55 -06:00
timers	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
tmpfs	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
tpm2	Kernel selftests: Add check if TPM devices are supported	2020-05-22 13:19:57 -06:00
uevent
user
vDSO	selftests: vdso: Add a selftest for vDSO getcpu()	2020-05-22 11:05:07 -06:00
vm	khugepaged: selftests: fix timeout condition in wait_for_scan()	2020-06-10 19:14:17 -07:00
watchdog	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
wireguard	wireguard: device: avoid circular netns references	2020-06-23 14:50:34 -07:00
x86	selftests/x86/pkeys: move selftests to arch-neutral directory	2020-06-04 19:06:26 -07:00
zram	docs: blockdev: add it to the admin-guide	2019-07-15 11:03:01 -03:00
.gitignore	SPDX patches for 5.7-rc1.	2020-04-03 13:12:26 -07:00
gen_kselftest_tar.sh	selftests: introduce gen_tar Makefile target	2020-05-19 16:11:46 -06:00
kselftest_deps.sh	selftests: add build/cross-build dependency check script	2020-04-23 17:23:20 -06:00
kselftest_harness.h	kselftest: add fixture variants	2020-04-28 13:30:44 -07:00
kselftest_install.sh	selftests: gen_kselftest_tar.sh: Do not clobber kselftest/	2019-11-07 14:43:27 -07:00
kselftest_module.h
kselftest.h	kselftest: save-and-restore errno to allow for %m formatting	2019-07-30 15:46:48 -06:00
lib.mk	linux-kselftest-5.7-rc1	2020-04-01 16:09:12 -07:00
Makefile	selftests: introduce gen_tar Makefile target	2020-05-19 16:11:46 -06:00