From d4d656cc71a66cd51b770485719626f6eceef0e7 Mon Sep 17 00:00:00 2001
From: Cedric Roux <cedric.roux@eurecom.fr>
Date: Tue, 12 Jul 2016 17:31:58 +0200
Subject: [PATCH] DO NOT MERGE THIS ONE!!
This commit drops RLC UM packets if the buffer occupancy is higher
than 16MB.
Let's say your UE can go up to 16Mb/s. If you do UDP iperf with
let's say 40Mb/s very quickly the buffer occupancy will reach
the 16Mb limit and following packets will get dropped.
Then something goes wrong. I don't know what. Just that iperf
reports very low throughput (I've seen down to 11 kb/s).
Stopping iperf, waiting for buffer to be empty and starting
again at let's say 10Mb/s does not provide 10Mb/s immediately,
but eventually it does, as if the RLC UM "goes back to normal".
So I don't know if it's a correct solution.
conclusion: DO NOT MERGE!!
Let's say it's work in progress, open for comments and
suggestions.
---
openair2/LAYER2/RLC/UM_v9.3.0/rlc_um.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/openair2/LAYER2/RLC/UM_v9.3.0/rlc_um.c b/openair2/LAYER2/RLC/UM_v9.3.0/rlc_um.c
index 7b0c9890e..7739e37bd 100755
--- a/openair2/LAYER2/RLC/UM_v9.3.0/rlc_um.c
+++ b/openair2/LAYER2/RLC/UM_v9.3.0/rlc_um.c
@@ -687,6 +687,14 @@ rlc_um_data_req (const protocol_ctxt_t* const ctxt_pP, void *rlc_pP, mem_block_t
char message_string[7000];
#endif
+ /* put a hard limit of 16MB */
+ if (rlc_p->buffer_occupancy > 16 * 1024 * 1024) {
+ free_mem_block(sdu_pP);
+ LOG_E(RLC, PROTOCOL_RLC_UM_CTXT_FMT" buffer full, dropping incoming data\n",
+ PROTOCOL_RLC_UM_CTXT_ARGS(ctxt_pP,rlc_p));
+ return;
+ }
+
LOG_D(RLC, PROTOCOL_RLC_UM_CTXT_FMT" RLC_UM_DATA_REQ size %d Bytes, BO %d , NB SDU %d\n",
PROTOCOL_RLC_UM_CTXT_ARGS(ctxt_pP,rlc_p),
((struct rlc_um_data_req *) (sdu_pP->data))->data_size,
--
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