diff options
| -rw-r--r-- | include/osmo-bts/gsm_data.h | 9 | ||||
| -rw-r--r-- | src/common/bts.c | 107 | ||||
| -rw-r--r-- | tests/agch/agch_test.c | 4 | ||||
| -rw-r--r-- | tests/agch/agch_test.ok | 2 |
4 files changed, 112 insertions, 10 deletions
diff --git a/include/osmo-bts/gsm_data.h b/include/osmo-bts/gsm_data.h index b1399034..c7a0fc61 100644 --- a/include/osmo-bts/gsm_data.h +++ b/include/osmo-bts/gsm_data.h @@ -7,6 +7,11 @@ #include <osmo-bts/paging.h> +#define GSM_BTS_AGCH_QUEUE_THRESH_LEVEL_DEFAULT 41 +#define GSM_BTS_AGCH_QUEUE_THRESH_LEVEL_DISABLE 999999 +#define GSM_BTS_AGCH_QUEUE_LOW_LEVEL_DEFAULT 41 +#define GSM_BTS_AGCH_QUEUE_HIGH_LEVEL_DEFAULT 91 + struct pcu_sock_state; struct gsm_network { @@ -54,6 +59,10 @@ struct gsm_bts_role_bts { int agch_queue_length; int agch_max_queue_length; + int agch_queue_thresh_level; /* Cleanup threshold in percent of max len */ + int agch_queue_low_level; /* Low water mark in percent of max len */ + int agch_queue_high_level; /* High water mark in percent of max len */ + /* TODO: Use a rate counter group instead */ uint64_t agch_queue_dropped_msgs; uint64_t agch_queue_merged_msgs; diff --git a/src/common/bts.c b/src/common/bts.c index 211bbbfa..d456f7fb 100644 --- a/src/common/bts.c +++ b/src/common/bts.c @@ -89,6 +89,14 @@ int bts_init(struct gsm_bts *bts) INIT_LLIST_HEAD(&btsb->agch_queue); btsb->agch_queue_length = 0; + /* enable management with default levels, + * raise threshold to GSM_BTS_AGCH_QUEUE_THRESH_LEVEL_DISABLE to + * disable this feature. + */ + btsb->agch_queue_low_level = GSM_BTS_AGCH_QUEUE_LOW_LEVEL_DEFAULT; + btsb->agch_queue_high_level = GSM_BTS_AGCH_QUEUE_HIGH_LEVEL_DEFAULT; + btsb->agch_queue_thresh_level = GSM_BTS_AGCH_QUEUE_THRESH_LEVEL_DEFAULT; + /* configurable via VTY */ btsb->paging_state = paging_init(btsb, 200, 0); @@ -301,6 +309,18 @@ void bts_update_agch_max_queue_length(struct gsm_bts *bts) int bts_agch_enqueue(struct gsm_bts *bts, struct msgb *msg) { struct gsm_bts_role_bts *btsb = bts_role_bts(bts); + int hard_limit = 1000; + + if (btsb->agch_queue_length > hard_limit) { + LOGP(DSUM, LOGL_ERROR, + "AGCH: too many messages in queue, " + "refusing message type 0x%02x, length = %d/%d\n", + ((struct gsm48_imm_ass *)msgb_l3(msg))->msg_type, + btsb->agch_queue_length, btsb->agch_max_queue_length); + + btsb->agch_queue_rejected_msgs++; + return -ENOMEM; + } msgb_enqueue(&btsb->agch_queue, msg); btsb->agch_queue_length++; @@ -319,26 +339,95 @@ struct msgb *bts_agch_dequeue(struct gsm_bts *bts) return msg; } +/* + * Remove lower prio messages if the queue has grown too long. + * + * \return 0 iff the number of messages in the queue would fit into the AGCH + * reserved part of the CCCH. + */ +static void compact_agch_queue(struct gsm_bts *bts) +{ + struct gsm_bts_role_bts *btsb = bts_role_bts(bts); + struct msgb *msg, *msg2; + int max_len, slope, offs; + int level_low = btsb->agch_queue_low_level; + int level_high = btsb->agch_queue_high_level; + int level_thres = btsb->agch_queue_thresh_level; + + max_len = btsb->agch_max_queue_length; + + if (max_len == 0) + max_len = 1; + + /* TODO: Make the constants configurable */ + if (btsb->agch_queue_length < max_len * level_thres / 100) + return; + + /* p^ + * 1+ /''''' + * | / + * | / + * 0+---/--+----+--> Q length + * low high max_len + */ + + offs = max_len * level_low / 100; + if (level_high > level_low) + slope = 0x10000 * 100 / (level_high - level_low); + else + slope = 0x10000 * max_len; /* p_drop >= 1 if len > offs */ + + llist_for_each_entry_safe(msg, msg2, &btsb->agch_queue, list) { + struct gsm48_imm_ass *imm_ass_cmd = msgb_l3(msg); + int p_drop; + + if (imm_ass_cmd->msg_type != GSM48_MT_RR_IMM_ASS_REJ) + return; + + /* IMMEDIATE ASSIGN REJECT */ + + p_drop = (btsb->agch_queue_length - offs) * slope / max_len; + + if ((random() & 0xffff) >= p_drop) + return; + + llist_del(&msg->list); + btsb->agch_queue_length--; + msgb_free(msg); + + btsb->agch_queue_dropped_msgs++; + } + return; +} + int bts_ccch_copy_msg(struct gsm_bts *bts, uint8_t *out_buf, struct gsm_time *gt, int is_ag_res) { - struct msgb *msg; + struct msgb *msg = NULL; struct gsm_bts_role_bts *btsb = bts->role; - int rc; + int rc = 0; + int is_empty = 1; + + /* Do queue house keeping. + * This needs to be done every time a CCCH message is requested, since + * the queue max length is calculated based on the CCCH block rate and + * PCH messages also reduce the drain of the AGCH queue. + */ + compact_agch_queue(bts); - if (!is_ag_res) { - int is_empty = 1; + /* Check for paging messages first if this is PCH */ + if (!is_ag_res) rc = paging_gen_msg(btsb->paging_state, out_buf, gt, &is_empty); - if (!is_empty) - return rc; - } + /* Check whether the block may be overwritten */ + if (!is_empty) + return rc; - /* special queue of messages from IMM ASS CMD */ msg = bts_agch_dequeue(bts); if (!msg) - return 0; + return rc; + /* Copy AGCH message */ memcpy(out_buf, msgb_l3(msg), msgb_l3len(msg)); rc = msgb_l3len(msg); msgb_free(msg); diff --git a/tests/agch/agch_test.c b/tests/agch/agch_test.c index 7a154874..6d00ed86 100644 --- a/tests/agch/agch_test.c +++ b/tests/agch/agch_test.c @@ -122,6 +122,10 @@ static void test_agch_queue(void) printf("Testing AGCH messages queue handling.\n"); btsb->agch_max_queue_length = 32; + btsb->agch_queue_low_level = 30; + btsb->agch_queue_high_level = 30; + btsb->agch_queue_thresh_level = 60; + for (round = 1; round <= num_rounds; round++) { for (idx = 0; idx < num_ima_per_round; idx++) { msg = msgb_alloc(GSM_MACBLOCK_LEN, __FUNCTION__); diff --git a/tests/agch/agch_test.ok b/tests/agch/agch_test.ok index f781383f..445d6840 100644 --- a/tests/agch/agch_test.ok +++ b/tests/agch/agch_test.ok @@ -19,5 +19,5 @@ T BCCH slots 50 28 14 28 28 28 Testing AGCH messages queue handling. AGCH filled: count 720, imm.ass 80, imm.ass.rej 640 (refs 640), queue limit 32, occupied 720, dropped 0, merged 0, rejected 0, ag-res 0, non-res 0 -AGCH drained: multiframes 241, imm.ass 80, imm.ass.rej 641 (refs 641), queue limit 32, occupied 0, dropped 0, merged 0, rejected 0, ag-res 240, non-res 480 +AGCH drained: multiframes 33, imm.ass 80, imm.ass.rej 17 (refs 17), queue limit 32, occupied 0, dropped 624, merged 0, rejected 0, ag-res 32, non-res 64 Success |