From 3388bd9e9b82df6d7fe79fa4eee7c22a3277624e Mon Sep 17 00:00:00 2001 From: Dimitri Staessens Date: Tue, 21 Jul 2026 06:54:55 +0200 Subject: ipcpd: Add flow overshoot protection to mb-ecn The ECN marks were the only source of congestion information, and going into congestion collapse (dropping a lot of ECN packets and causing loss of signal) was unrecoverable. The sender's slow-start ramp clock now tracks a measured RTT to avoid overshooting into congestion collapse on the previously fixed (14ms) doubling on long-delay (e.g. 100ms) links. The flow allocator now carries a periodic heartbeat/ack to keep RTT estimates up-to-date. The heartbeat also serves as a congestion collapse detector: consecutive heartbeat losses will go into loss recovery, halving the window and pausing Additive Increase until the path is clear. The DT component now has a max_rtt config parameter that serves as a hint for the layer RTT to optimize slow-start for low-latency networks. These two mechanisms follow TCP, however only during slow start up to the first ECN signal and to recover from a total collapse until the ECN signal returns. MB-ECN is still fully RTT-independent in the AI/PD region. A shorter RTT path will just reach its equal fair share faster than a longer RTT path. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders --- src/ipcpd/unicast/ca/tests/ca_test.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'src/ipcpd/unicast/ca/tests/ca_test.c') diff --git a/src/ipcpd/unicast/ca/tests/ca_test.c b/src/ipcpd/unicast/ca/tests/ca_test.c index 4c44d29e..1b86eab8 100644 --- a/src/ipcpd/unicast/ca/tests/ca_test.c +++ b/src/ipcpd/unicast/ca/tests/ca_test.c @@ -44,7 +44,7 @@ static int test_ca_init_fini(enum pol_cong_avoid pol, { TEST_START("(%s)", name); - if (ca_init(pol) < 0) { + if (ca_init(pol, 100) < 0) { printf("Failed to init ca for %s.\n", name); goto fail; } @@ -74,7 +74,7 @@ static int test_ca_init_invalid(void) { TEST_START(); - if (ca_init(CA_INVALID) == 0) { + if (ca_init(CA_INVALID, 100) == 0) { printf("Init accepted an invalid policy.\n"); ca_fini(); goto fail; @@ -96,7 +96,7 @@ static int test_ca_ctx_share(enum pol_cong_avoid pol, TEST_START("(%s)", name); - if (ca_init(pol) < 0) { + if (ca_init(pol, 100) < 0) { printf("Failed to init ca for %s.\n", name); goto fail; } @@ -162,7 +162,7 @@ static int test_ca_ctx_distinct(void) TEST_START(); - if (ca_init(CA_NONE) < 0) { + if (ca_init(CA_NONE, 100) < 0) { printf("Failed to init ca.\n"); goto fail; } @@ -226,7 +226,7 @@ static int test_ca_ctx_refcount(void) TEST_START(); - if (ca_init(CA_NONE) < 0) { + if (ca_init(CA_NONE, 100) < 0) { printf("Failed to init ca.\n"); goto fail; } @@ -283,7 +283,7 @@ static int test_ca_ctx_recreate(void) TEST_START(); - if (ca_init(CA_NONE) < 0) { + if (ca_init(CA_NONE, 100) < 0) { printf("Failed to init ca.\n"); goto fail; } @@ -340,7 +340,7 @@ static int test_ca_fini_drains(void) TEST_START(); - if (ca_init(CA_NONE) < 0) { + if (ca_init(CA_NONE, 100) < 0) { printf("Failed to init ca.\n"); goto fail; } -- cgit v1.2.3