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| author | Dimitri Staessens <dimitri@ouroboros.rocks> | 2020-12-06 14:24:51 +0100 |
|---|---|---|
| committer | Sander Vrijders <sander@ouroboros.rocks> | 2020-12-07 18:39:45 +0100 |
| commit | e5fdcfb3cfee29385c44bf487638ac5a535ee5d6 (patch) | |
| tree | f47593caaaf93e573a4d2a37907d0e380ab14e8b | |
| parent | f52e231e3e71fa97276260d87f192701e2232614 (diff) | |
| download | ouroboros-e5fdcfb3cfee29385c44bf487638ac5a535ee5d6.tar.gz ouroboros-e5fdcfb3cfee29385c44bf487638ac5a535ee5d6.zip | |
ipcpd: Fix slow start in multi-bit (F)ECN policy
There is a check not to rapidly double the window to astronomical
sizes when there is no congestion experienced for long periods of
time, but the if-else logic was botched and it still grew to
astronomical sizes (albeit linear instead of exponential).
I also lowered the ECN threshold a bit.
Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>
| -rw-r--r-- | src/ipcpd/unicast/pol/ca-mb-ecn.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/src/ipcpd/unicast/pol/ca-mb-ecn.c b/src/ipcpd/unicast/pol/ca-mb-ecn.c index 31a646b2..1baaca7a 100644 --- a/src/ipcpd/unicast/pol/ca-mb-ecn.c +++ b/src/ipcpd/unicast/pol/ca-mb-ecn.c @@ -46,7 +46,7 @@ #define CA_IWL 1 << 16 /* Initial limit ~4MiB/s */ #define CA_MINPS 8 /* Mimimum pkts / slot */ #define CA_MAXPS 64 /* Maximum pkts / slot */ -#define ECN_Q_SHFT 5 +#define ECN_Q_SHFT 4 #define ts_to_ns(ts) (ts.tv_sec * BILLION + ts.tv_nsec) struct mb_ecn_ctx { @@ -127,13 +127,16 @@ ca_wnd_t mb_ecn_ctx_update_snd(void * _ctx, if (slot > ctx->tx_slot) { ctx->tx_slot = slot; - if (!ctx->tx_cav && ctx->tx_wbc > ctx->tx_wbl) /* Slow start */ - ctx->tx_wbl <<= 1; - else if (ctx->tx_ece) /* Multiplicative Decrease */ - ctx->tx_wbl -= (ctx->tx_wbl * ctx->tx_ece) - >> (CA_SHFT + 8); - else /* Additive Increase */ - ctx->tx_wbl = ctx->tx_wbl + ctx->tx_inc; + if (!ctx->tx_cav) { /* Slow start */ + if (ctx->tx_wbc > ctx->tx_wbl) + ctx->tx_wbl <<= 1; + } else { + if (ctx->tx_ece) /* Mult. Decrease */ + ctx->tx_wbl -= (ctx->tx_wbl * ctx->tx_ece) + >> (CA_SHFT + 8); + else if (ctx->tx_wbc > ctx->tx_wbl) /* Add. Increase */ + ctx->tx_wbl = ctx->tx_wbl + ctx->tx_inc; + } /* Window scaling */ if (ctx->tx_wpc < CA_MINPS) { |