diff options
Diffstat (limited to 'src/osmo-bsc/paging.c')
| -rw-r--r-- | src/osmo-bsc/paging.c | 729 |
1 files changed, 521 insertions, 208 deletions
diff --git a/src/osmo-bsc/paging.c b/src/osmo-bsc/paging.c index 15aca00ea..e6f6fe4ef 100644 --- a/src/osmo-bsc/paging.c +++ b/src/osmo-bsc/paging.c @@ -54,21 +54,52 @@ #include <osmocom/bsc/gsm_04_08_rr.h> #include <osmocom/bsc/bsc_subscr_conn_fsm.h> #include <osmocom/bsc/bts.h> +#include <osmocom/bsc/bsc_stats.h> void *tall_paging_ctx = NULL; -#define PAGING_TIMER 0, 500000 +/* How many paging requests to Tx on RSL at max before going back to main loop */ +#define MAX_PAGE_REQ_PER_ITER 10 + +/* How often to attempt sending new paging requests (initial, not retrans): 250ms */ +static const struct timespec initial_period = { + .tv_sec = 0, + .tv_nsec = 250 * 1000 * 1000, +}; + +/* Minimum period between retransmits of paging req to a subscriber: 500ms */ +static const struct timespec retrans_period = { + .tv_sec = 0, + .tv_nsec = 500 * 1000 * 1000, +}; + +/* If no CCCH Lod Ind is received before this time period, the BTS is considered + * to have stopped sending CCCH Load Indication, probaby due to being under Load + * Threshold: */ +#define bts_no_ccch_load_ind_timeout_sec(bts) ((bts)->ccch_load_ind_period * 2) /* * Kill one paging request update the internal list... */ -static void paging_remove_request(struct gsm_bts_paging_state *paging_bts, - struct gsm_paging_request *to_be_deleted) +static void paging_remove_request(struct gsm_paging_request *req) { - osmo_timer_del(&to_be_deleted->T3113); - llist_del(&to_be_deleted->entry); - bsc_subscr_put(to_be_deleted->bsub, BSUB_USE_PAGING_REQUEST); - talloc_free(to_be_deleted); + struct gsm_bts *bts = req->bts; + struct gsm_bts_paging_state *bts_pag_st = &bts->paging; + + osmo_timer_del(&req->T3113); + llist_del(&req->entry); + if (req->attempts == 0) { + bts_pag_st->initial_req_list_len--; + bts_pag_st->initial_req_pgroup_counts[req->pgroup]--; + } else { + bts_pag_st->retrans_req_list_len--; + } + osmo_stat_item_dec(osmo_stat_item_group_get_item(bts->bts_statg, BTS_STAT_PAGING_REQ_QUEUE_LENGTH), 1); + bsc_subscr_remove_active_paging_request(req->bsub, req); + talloc_free(req); + + if (llist_empty(&bts_pag_st->initial_req_list) && llist_empty(&bts_pag_st->retrans_req_list)) + osmo_timer_del(&bts_pag_st->work_timer); } static void page_ms(struct gsm_paging_request *request) @@ -79,9 +110,9 @@ static void page_ms(struct gsm_paging_request *request) log_set_context(LOG_CTX_BSC_SUBSCR, request->bsub); - LOG_BTS(bts, DPAG, LOGL_INFO, "Going to send paging commands: %s" - " for ch. type %d (attempt %d)\n", bsc_subscr_name(request->bsub), - request->chan_type, request->attempts); + LOG_PAGING_BTS(request, bts, DPAG, LOGL_INFO, + "Going to send paging command for ch. type %d (attempt %d)\n", + request->chan_type, request->attempts); if (request->bsub->tmsi == GSM_RESERVED_TMSI) { mi = (struct osmo_mobile_identity){ @@ -101,24 +132,35 @@ static void page_ms(struct gsm_paging_request *request) log_set_context(LOG_CTX_BSC_SUBSCR, NULL); } +static void paging_handle_pending_requests(struct gsm_bts_paging_state *paging_bts); + static void paging_schedule_if_needed(struct gsm_bts_paging_state *paging_bts) { - if (llist_empty(&paging_bts->pending_requests)) - return; - + /* paging_handle_pending_requests() will schedule work_timer if work + * needs to be partitioned in several iterations. */ if (!osmo_timer_pending(&paging_bts->work_timer)) - osmo_timer_schedule(&paging_bts->work_timer, PAGING_TIMER); + paging_handle_pending_requests(paging_bts); } +/* Placeholder to set the value and update the related osmo_stat: */ +static void paging_set_available_slots(struct gsm_bts *bts, uint16_t available_slots) +{ + bts->paging.available_slots = available_slots; + osmo_stat_item_set(osmo_stat_item_group_get_item(bts->bts_statg, BTS_STAT_PAGING_AVAILABLE_SLOTS), available_slots); +} -static void paging_handle_pending_requests(struct gsm_bts_paging_state *paging_bts); static void paging_give_credit(void *data) { - struct gsm_bts_paging_state *paging_bts = data; - - LOG_BTS(paging_bts->bts, DPAG, LOGL_NOTICE, "No PCH LOAD IND, adding 20 slots)\n"); - paging_bts->available_slots = 20; - paging_handle_pending_requests(paging_bts); + struct gsm_bts_paging_state *paging_bts_st = data; + struct gsm_bts *bts = paging_bts_st->bts; + unsigned int load_ind_timeout = bts_no_ccch_load_ind_timeout_sec(bts); + uint16_t estimated_slots = paging_estimate_available_slots(bts, load_ind_timeout); + LOG_BTS(bts, DPAG, LOGL_INFO, + "Timeout waiting for CCCH Load Indication, assuming BTS is below Load Threshold (available_slots %u -> %u)\n", + paging_bts_st->available_slots, estimated_slots); + paging_set_available_slots(bts, estimated_slots); + paging_schedule_if_needed(paging_bts_st); + osmo_timer_schedule(&bts->paging.credit_timer, load_ind_timeout, 0); } /*! count the number of free channels for given RSL channel type required @@ -171,6 +213,149 @@ count_tch: return bts->paging.free_chans_need > count; } +static void paging_req_timeout_retrans(struct gsm_paging_request *request, const struct timespec *now) +{ + struct gsm_bts_paging_state *bts_pag_st = &request->bts->paging; + page_ms(request); + paging_set_available_slots(request->bts, bts_pag_st->available_slots - 1); + + if (request->attempts == 0) { + /* req is removed from initial_req_list and inserted into retrans_req_list, update list lengths: */ + bts_pag_st->initial_req_list_len--; + bts_pag_st->initial_req_pgroup_counts[request->pgroup]--; + bts_pag_st->retrans_req_list_len++; + } + llist_del(&request->entry); + llist_add_tail(&request->entry, &bts_pag_st->retrans_req_list); + + request->last_attempt_ts = *now; + request->attempts++; +} + +/* Returns number of paged initial requests (up to max_page_req_per_iter). + * Returning work_done=false means the work timer has been scheduled internally and the caller should avoid processing + * further requests right now. + */ +static unsigned int step_page_initial_reqs(struct gsm_bts_paging_state *bts_pag_st, unsigned int max_page_req_per_iter, + const struct timespec *now, bool *work_done) +{ + struct gsm_paging_request *request, *request2; + unsigned int num_paged = 0; + + llist_for_each_entry_safe(request, request2, &bts_pag_st->initial_req_list, entry) { + /* We run out of available slots. Wait until next CCCH Load Ind + * arrives or credit_timer triggers to keep processing requests. + */ + if (bts_pag_st->available_slots == 0) { + LOG_PAGING_BTS(request, request->bts, DPAG, LOGL_INFO, + "Paging delayed: waiting for available slots at BTS\n"); + *work_done = false; + return num_paged; + } + + if (num_paged == max_page_req_per_iter) { + goto sched_next_iter; + } + + /* we need to determine the number of free channels */ + if (bts_pag_st->free_chans_need != -1 && + can_send_pag_req(request->bts, request->chan_type) != 0) { + LOG_PAGING_BTS(request, request->bts, DPAG, LOGL_INFO, + "Paging delayed: not enough free channels (<%d)\n", + bts_pag_st->free_chans_need); + goto sched_next_iter; + } + + /* handle the paging request now */ + paging_req_timeout_retrans(request, now); + num_paged++; + } + + *work_done = true; + return num_paged; + +sched_next_iter: + LOG_BTS(bts_pag_st->bts, DPAG, LOGL_DEBUG, "Scheduling next batch in %lld.%06lds (available_slots=%u)\n", + (long long)initial_period.tv_sec, initial_period.tv_nsec / 1000, + bts_pag_st->available_slots); + osmo_timer_schedule(&bts_pag_st->work_timer, initial_period.tv_sec, initial_period.tv_nsec / 1000); + *work_done = false; + return num_paged; +} + +static unsigned int step_page_retrans_reqs(struct gsm_bts_paging_state *bts_pag_st, unsigned int max_page_req_per_iter, + const struct timespec *now) +{ + struct gsm_paging_request *request, *initial_request; + unsigned int num_paged = 0; + struct timespec retrans_ts; + + /* do while loop: Try send at most first max_page_req_per_iter paging + * requests. Since transmitted requests are re-appended at the end of + * the list, we check until we find the first req again, in order to + * avoid retransmitting repeated requests until next time paging is + * scheduled. */ + initial_request = llist_first_entry_or_null(&bts_pag_st->retrans_req_list, + struct gsm_paging_request, entry); + if (!initial_request) + return num_paged; + + request = initial_request; + do { + /* We run out of available slots. Wait until next CCCH Load Ind + * arrives or credit_timer triggers to keep processing requests. + */ + if (bts_pag_st->available_slots == 0) { + LOG_PAGING_BTS(request, request->bts, DPAG, LOGL_INFO, + "Paging delayed: waiting for available slots at BTS\n"); + return num_paged; + } + + /* we need to determine the number of free channels */ + if (bts_pag_st->free_chans_need != -1 && + can_send_pag_req(request->bts, request->chan_type) != 0) { + LOG_PAGING_BTS(request, request->bts, DPAG, LOGL_INFO, + "Paging delayed: not enough free channels (<%d)\n", + bts_pag_st->free_chans_need); + goto sched_next_iter; + } + + /* Check if time to retransmit has elapsed. Otherwise, wait until its time to retransmit. */ + timespecadd(&request->last_attempt_ts, &retrans_period, &retrans_ts); + if (timespeccmp(now, &retrans_ts, <)) { + struct timespec tdiff; + timespecsub(&retrans_ts, now, &tdiff); + LOG_PAGING_BTS(request, request->bts, DPAG, LOGL_DEBUG, + "Paging delayed: retransmission happens in %lld.%06lds\n", + (long long)tdiff.tv_sec, tdiff.tv_nsec / 1000); + osmo_timer_schedule(&bts_pag_st->work_timer, tdiff.tv_sec, tdiff.tv_nsec / 1000); + return num_paged; + } + + if (num_paged >= max_page_req_per_iter) + goto sched_next_iter; + + /* handle the paging request now */ + paging_req_timeout_retrans(request, now); + num_paged++; + + request = llist_first_entry(&bts_pag_st->retrans_req_list, + struct gsm_paging_request, entry); + } while (request != initial_request); + + /* Reaching this code paths means all retrans request have been scheduled (and intial_req_list is empty). + * Hence, reeschedule ourselves to now + retrans_period. */ + osmo_timer_schedule(&bts_pag_st->work_timer, retrans_period.tv_sec, retrans_period.tv_nsec / 1000); + return num_paged; + +sched_next_iter: + LOG_BTS(bts_pag_st->bts, DPAG, LOGL_DEBUG, "Scheduling next batch in %lld.%06lds (available_slots=%u)\n", + (long long)initial_period.tv_sec, initial_period.tv_nsec / 1000, + bts_pag_st->available_slots); + osmo_timer_schedule(&bts_pag_st->work_timer, initial_period.tv_sec, initial_period.tv_nsec / 1000); + return num_paged; +} + /* * This is kicked by the periodic PAGING LOAD Indicator * coming from abis_rsl.c @@ -180,54 +365,30 @@ count_tch: */ static void paging_handle_pending_requests(struct gsm_bts_paging_state *paging_bts) { - struct gsm_paging_request *request = NULL; + unsigned int num_paged_initial, num_paged_retrans = 0; + unsigned int max_page_req_per_iter = MAX_PAGE_REQ_PER_ITER; + struct timespec now; + bool work_done = false; /* * Determine if the pending_requests list is empty and * return then. */ - if (llist_empty(&paging_bts->pending_requests)) { - /* since the list is empty, no need to reschedule the timer */ - return; - } - - /* - * In case the BTS does not provide us with load indication and we - * ran out of slots, call an autofill routine. It might be that the - * BTS did not like our paging messages and then we have counted down - * to zero and we do not get any messages. - */ - if (paging_bts->available_slots == 0) { - osmo_timer_setup(&paging_bts->credit_timer, paging_give_credit, - paging_bts); - osmo_timer_schedule(&paging_bts->credit_timer, 5, 0); + if (llist_empty(&paging_bts->initial_req_list) && + llist_empty(&paging_bts->retrans_req_list)) { + /* since the lists are empty, no need to reschedule the timer */ return; } - request = llist_entry(paging_bts->pending_requests.next, - struct gsm_paging_request, entry); + osmo_clock_gettime(CLOCK_MONOTONIC, &now); + paging_bts->last_sched_ts = now; - /* we need to determine the number of free channels */ - if (paging_bts->free_chans_need != -1) { - if (can_send_pag_req(request->bts, request->chan_type) != 0) - goto skip_paging; - } + num_paged_initial = step_page_initial_reqs(paging_bts, max_page_req_per_iter, &now, &work_done); + if (work_done) /* All work done for initial requests, work on retransmissions now: */ + num_paged_retrans = step_page_retrans_reqs(paging_bts, max_page_req_per_iter - num_paged_initial, &now); - /* Skip paging if the bts is down. */ - if (!request->bts->oml_link) - goto skip_paging; - - /* handle the paging request now */ - page_ms(request); - paging_bts->available_slots--; - request->attempts++; - - /* take the current and add it to the back */ - llist_del(&request->entry); - llist_add_tail(&request->entry, &paging_bts->pending_requests); - -skip_paging: - osmo_timer_schedule(&paging_bts->work_timer, PAGING_TIMER); + LOG_BTS(paging_bts->bts, DPAG, LOGL_DEBUG, "Paged %u subscribers (%u initial, %u retrans) during last iteration\n", + num_paged_initial + num_paged_retrans, num_paged_initial, num_paged_retrans); } static void paging_worker(void *data) @@ -238,36 +399,23 @@ static void paging_worker(void *data) } /*! initialize the bts paging state, if it hasn't been initialized yet */ -static void paging_init_if_needed(struct gsm_bts *bts) +void paging_init(struct gsm_bts *bts) { - if (bts->paging.bts) - return; - bts->paging.bts = bts; - - /* This should be initialized only once. There is currently no code that sets bts->paging.bts - * back to NULL, so let's just assert this one instead of graceful handling. */ - OSMO_ASSERT(llist_empty(&bts->paging.pending_requests)); - - osmo_timer_setup(&bts->paging.work_timer, paging_worker, - &bts->paging); - - /* Large number, until we get a proper message */ - bts->paging.available_slots = 20; + bts->paging.free_chans_need = -1; + paging_set_available_slots(bts, 0); + INIT_LLIST_HEAD(&bts->paging.initial_req_list); + INIT_LLIST_HEAD(&bts->paging.retrans_req_list); + osmo_timer_setup(&bts->paging.work_timer, paging_worker, &bts->paging); + osmo_timer_setup(&bts->paging.credit_timer, paging_give_credit, &bts->paging); } -/*! do we have any pending paging requests for given subscriber? */ -static int paging_pending_request(struct gsm_bts_paging_state *bts, - struct bsc_subscr *bsub) +/* Called upon the bts struct being freed */ +void paging_destructor(struct gsm_bts *bts) { - struct gsm_paging_request *req; - - llist_for_each_entry(req, &bts->pending_requests, entry) { - if (bsub == req->bsub) - return 1; - } - - return 0; + paging_flush_bts(bts, NULL); + osmo_timer_del(&bts->paging.credit_timer); + osmo_timer_del(&bts->paging.work_timer); } /*! Call-back once T3113 (paging timeout) expires for given paging_request */ @@ -277,45 +425,72 @@ static void paging_T3113_expired(void *data) log_set_context(LOG_CTX_BSC_SUBSCR, req->bsub); - LOGP(DPAG, LOGL_INFO, "T3113 expired for request %p (%s)\n", - req, bsc_subscr_name(req->bsub)); + LOG_PAGING_BTS(req, req->bts, DPAG, LOGL_INFO, "T3113 expired\n"); /* must be destroyed before calling cbfn, to prevent double free */ - rate_ctr_inc(&req->bts->bts_ctrs->ctr[BTS_CTR_PAGING_EXPIRED]); + rate_ctr_inc(rate_ctr_group_get_ctr(req->bts->bts_ctrs, BTS_CTR_PAGING_EXPIRED)); + + /* If last BTS paging times out (active_paging_requests will be + * decremented in paging_remove_request below): */ + if (req->bsub->active_paging_requests_len == 1) + rate_ctr_inc(rate_ctr_group_get_ctr(bsc_gsmnet->bsc_ctrs, BSC_CTR_PAGING_EXPIRED)); /* destroy it now. Do not access req afterwards */ - paging_remove_request(&req->bts->paging, req); + paging_remove_request(req); log_set_context(LOG_CTX_BSC_SUBSCR, NULL); } -#define GSM_FRAME_DURATION_us 4615 -#define GSM51_MFRAME_DURATION_us (51 * GSM_FRAME_DURATION_us) /* 235365 us */ -static unsigned int calculate_timer_3113(struct gsm_bts *bts) +#define GSM51_MFRAME_DURATION_us (51 * GSM_TDMA_FN_DURATION_uS) /* 235365 us */ +static unsigned int paging_estimate_delay_us(struct gsm_bts *bts, unsigned int num_reqs, + unsigned int num_reqs_same_pgroup); + +static unsigned int calculate_timer_3113(struct gsm_paging_request *req, unsigned int reqs_before, + unsigned int reqs_before_same_pgroup, unsigned int max_dynamic_value) { - unsigned int to_us, to; + unsigned int to_us, estimated_to, to; + struct gsm_bts *bts = req->bts; struct osmo_tdef *d = osmo_tdef_get_entry(bts->network->T_defs, 3113); + unsigned int rach_max_trans, rach_tx_integer, bs_pa_mfrms; /* Note: d should always contain a valid pointer since all timers, * including 3113 are statically pre-defined in * struct osmo_tdef gsm_network_T_defs. */ OSMO_ASSERT(d); - if (!bts->T3113_dynamic) - return d->val; - - /* TODO: take into account load of paging group for req->bsub */ + if (!bts->T3113_dynamic) { + to = d->val; + goto ret; + } /* MFRMS defines repeat interval of paging messages for MSs that belong * to same paging group across multiple 51 frame multiframes. - * MAXTRANS defines maximum number of RACH retransmissions. + * MAXTRANS defines maximum number of RACH retransmissions, spread over + * TXINTEGER slots. */ - to_us = GSM51_MFRAME_DURATION_us * (bts->si_common.chan_desc.bs_pa_mfrms + 2) * - bts->si_common.rach_control.max_trans; + rach_max_trans = rach_max_trans_raw2val(bts->si_common.rach_control.max_trans); + rach_tx_integer = rach_tx_integer_raw2val(bts->si_common.rach_control.tx_integer); + bs_pa_mfrms = (bts->si_common.chan_desc.bs_pa_mfrms + 2); + to_us = GSM51_MFRAME_DURATION_us * bs_pa_mfrms + + GSM_TDMA_FN_DURATION_uS * rach_tx_integer * rach_max_trans; + + /* Now add some extra time based on how many requests need to be transmitted before this one: */ + to_us += paging_estimate_delay_us(bts, reqs_before, reqs_before_same_pgroup); /* ceiling in seconds + extra time */ - to = (to_us + 999999) / 1000000 + d->val; - LOG_BTS(bts, DPAG, LOGL_DEBUG, "Paging request: T3113 expires in %u seconds\n", to); + estimated_to = (to_us + 999999) / 1000000 + d->val; + + /* upper bound: see X3113, PAGING_THRESHOLD_X3113_DEFAULT_SEC */ + if (estimated_to > max_dynamic_value) + to = max_dynamic_value; + else + to = estimated_to; + + LOG_PAGING_BTS(req, bts, DPAG, LOGL_DEBUG, + "Paging request: T3113 expires in %u seconds (estimated %u)\n", + to, estimated_to); +ret: + osmo_stat_item_set(osmo_stat_item_group_get_item(bts->bts_statg, BTS_STAT_PAGING_T3113), to); return to; } @@ -330,29 +505,83 @@ static int _paging_request(const struct bsc_paging_params *params, struct gsm_bt struct gsm_bts_paging_state *bts_entry = &bts->paging; struct gsm_paging_request *req; unsigned int t3113_timeout_s; + unsigned int x3113_s = osmo_tdef_get(bts->network->T_defs, -3113, OSMO_TDEF_S, -1); + uint8_t pgroup; + unsigned int reqs_before, reqs_before_same_pgroup; - rate_ctr_inc(&bts->bts_ctrs->ctr[BTS_CTR_PAGING_ATTEMPTED]); + rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_CTR_PAGING_ATTEMPTED)); - if (paging_pending_request(bts_entry, params->bsub)) { + /* Find if we already have one for the given subscriber on this BTS: */ + if (bsc_subscr_find_req_by_bts(params->bsub, bts)) { LOG_PAGING_BTS(params, bts, DPAG, LOGL_INFO, "Paging request already pending for this subscriber\n"); - rate_ctr_inc(&bts->bts_ctrs->ctr[BTS_CTR_PAGING_ALREADY]); + rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_CTR_PAGING_ALREADY)); return -EEXIST; } + /* Don't try to queue more requests than we can realistically handle within X3113 seconds, + * see PAGING_THRESHOLD_X3113_DEFAULT_SEC. */ + if (paging_pending_requests_nr(bts) > paging_estimate_available_slots(bts, x3113_s)) { + struct gsm_paging_request *first_retrans_req; + rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_CTR_PAGING_OVERLOAD)); + /* Need to drop a retrans from the queue if possible, in order to make space for the new initial req. */ + if (bts_entry->retrans_req_list_len == 0) { + /* There are no retrans to be replaced by this initial request, discard it. */ + return -ENOSPC; + } + first_retrans_req = llist_first_entry(&bts_entry->retrans_req_list, struct gsm_paging_request, entry); + paging_remove_request(first_retrans_req); + } + + pgroup = gsm0502_calc_paging_group(&bts->si_common.chan_desc, str_to_imsi(params->bsub->imsi)); + reqs_before = bts_entry->initial_req_list_len; + reqs_before_same_pgroup = bts_entry->initial_req_pgroup_counts[pgroup]; + LOG_PAGING_BTS(params, bts, DPAG, LOGL_DEBUG, "Start paging\n"); req = talloc_zero(tall_paging_ctx, struct gsm_paging_request); OSMO_ASSERT(req); req->reason = params->reason; req->bsub = params->bsub; - bsc_subscr_get(req->bsub, BSUB_USE_PAGING_REQUEST); req->bts = bts; req->chan_type = params->chan_needed; + req->pgroup = pgroup; req->msc = params->msc; osmo_timer_setup(&req->T3113, paging_T3113_expired, req); - t3113_timeout_s = calculate_timer_3113(bts); + bsc_subscr_add_active_paging_request(req->bsub, req); + + bts_entry->initial_req_list_len++; + bts_entry->initial_req_pgroup_counts[req->pgroup]++; + osmo_stat_item_inc(osmo_stat_item_group_get_item(bts->bts_statg, BTS_STAT_PAGING_REQ_QUEUE_LENGTH), 1); + llist_add_tail(&req->entry, &bts_entry->initial_req_list); + + t3113_timeout_s = calculate_timer_3113(req, reqs_before, reqs_before_same_pgroup, x3113_s); osmo_timer_schedule(&req->T3113, t3113_timeout_s, 0); - llist_add_tail(&req->entry, &bts_entry->pending_requests); - paging_schedule_if_needed(bts_entry); + + /* Trigger scheduler if needed: */ + if (!osmo_timer_pending(&bts_entry->work_timer)) { + paging_handle_pending_requests(bts_entry); + } else if (bts_entry->initial_req_list_len == 1) { + /* Worker timer is armed -> there was already one req before + * bts_entry->initial_req_list_len == 1 -> There were no initial requests + * in the list, aka the timer is waiting for retransmition, + * which is a longer period. + * Let's recaculate the time to adapt it to initial_period: */ + struct timespec now, elapsed, tdiff; + osmo_clock_gettime(CLOCK_MONOTONIC, &now); + timespecsub(&now, &bts_entry->last_sched_ts, &elapsed); + if (timespeccmp(&elapsed, &initial_period, <)) { + timespecsub(&initial_period, &elapsed, &tdiff); + } else { + tdiff = (struct timespec){.tv_sec = 0, .tv_nsec = 0 }; + } + LOG_PAGING_BTS(req, req->bts, DPAG, LOGL_DEBUG, + "New req arrived: re-scheduling next batch in %lld.%06lds\n", + (long long)tdiff.tv_sec, tdiff.tv_nsec / 1000); + /* Avoid scheduling timer for short periods, run cb directly: */ + if (tdiff.tv_sec == 0 && tdiff.tv_nsec < 5000) + paging_worker(bts_entry); + else + osmo_timer_schedule(&bts_entry->work_timer, tdiff.tv_sec, tdiff.tv_nsec / 1000); + } /* else: worker is already ongoing submitting initial requests, nothing do be done */ return 0; } @@ -371,9 +600,6 @@ int paging_request_bts(const struct bsc_paging_params *params, struct gsm_bts *b if (!trx_is_usable(bts->c0)) return 0; - /* maybe it is the first time we use it */ - paging_init_if_needed(bts); - /* Trigger paging, pass any error to the caller */ rc = _paging_request(params, bts); if (rc < 0) @@ -381,128 +607,100 @@ int paging_request_bts(const struct bsc_paging_params *params, struct gsm_bts *b return 1; } -/*! Stop paging a given subscriber on a given BTS. - * \param[out] returns the MSC that paged the subscriber, if any. - * \param[out] returns the reason for a pending paging, if any. - * \param[in] bts BTS which has received a paging response. - * \param[in] bsub subscriber. - * \returns number of pending pagings. - */ -static int paging_request_stop_bts(struct bsc_msc_data **msc_p, enum bsc_paging_reason *reason_p, - struct gsm_bts *bts, struct bsc_subscr *bsub) -{ - struct gsm_bts_paging_state *bts_entry = &bts->paging; - struct gsm_paging_request *req, *req2; - - *msc_p = NULL; - *reason_p = BSC_PAGING_NONE; - - paging_init_if_needed(bts); - - llist_for_each_entry_safe(req, req2, &bts_entry->pending_requests, - entry) { - if (req->bsub != bsub) - continue; - *msc_p = req->msc; - *reason_p = req->reason; - LOG_BTS(bts, DPAG, LOGL_DEBUG, "Stop paging %s\n", bsc_subscr_name(bsub)); - paging_remove_request(&bts->paging, req); - return 1; - } - - return 0; -} - /*! Stop paging on all cells and return the MSC that paged (if any) and all pending paging reasons. * \param[out] returns the MSC that paged the subscriber, if there was a pending request. * \param[out] returns the ORed bitmask of all reasons of pending pagings. * \param[in] bts BTS which has received a paging response * \param[in] bsub subscriber - * \returns number of pending pagings. */ -int paging_request_stop(struct bsc_msc_data **msc_p, enum bsc_paging_reason *reasons_p, +void paging_request_stop(struct bsc_msc_data **msc_p, enum bsc_paging_reason *reasons_p, struct gsm_bts *bts, struct bsc_subscr *bsub) { - struct gsm_bts *bts_i; - struct bsc_msc_data *paged_from_msc; - int count; - enum bsc_paging_reason reasons; + struct bsc_msc_data *paged_from_msc = NULL; + enum bsc_paging_reason reasons = BSC_PAGING_NONE; OSMO_ASSERT(bts); - - count = paging_request_stop_bts(&paged_from_msc, &reasons, bts, bsub); - if (paged_from_msc) { - count++; - rate_ctr_inc(&bts->bts_ctrs->ctr[BTS_CTR_PAGING_RESPONDED]); - rate_ctr_inc(&bts->network->bsc_ctrs->ctr[BSC_CTR_PAGING_RESPONDED]); + struct gsm_paging_request *req = bsc_subscr_find_req_by_bts(bsub, bts); + + /* Avoid accessing bsub after reaching 0 active_paging_request_len, + * since it could be freed during put(): */ + unsigned remaining = bsub->active_paging_requests_len; + + if (req) { + paged_from_msc = req->msc; + reasons = req->reason; + LOG_PAGING_BTS(req, bts, DPAG, LOGL_DEBUG, "Stop paging\n"); + rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_CTR_PAGING_RESPONDED)); + rate_ctr_inc(rate_ctr_group_get_ctr(bts->network->bsc_ctrs, BSC_CTR_PAGING_RESPONDED)); + paging_remove_request(req); + remaining--; } - llist_for_each_entry(bts_i, &bsc_gsmnet->bts_list, list) { - struct bsc_msc_data *paged_from_msc2; - enum bsc_paging_reason reason2; - count += paging_request_stop_bts(&paged_from_msc2, &reason2, bts_i, bsub); - if (paged_from_msc2) { - reasons |= reason2; - if (!paged_from_msc) { - /* If this happened, it would be a bit weird: it means there was no Paging Request - * pending on the BTS that sent the Paging Reponse, but there *is* a Paging Request - * pending on a different BTS. But why not return an MSC when we found one. */ - paged_from_msc = paged_from_msc2; - } + while (remaining > 0) { + struct gsm_paging_request *req; + req = llist_first_entry(&bsub->active_paging_requests, + struct gsm_paging_request, bsub_entry); + LOG_PAGING_BTS(req, req->bts, DPAG, LOGL_DEBUG, "Stop paging\n"); + reasons |= req->reason; + if (!paged_from_msc) { + /* If this happened, it would be a bit weird: it means there was no Paging Request + * pending on the BTS that sent the Paging Response, but there *is* a Paging Request + * pending on a different BTS. But why not return an MSC when we found one. */ + paged_from_msc = req->msc; } + paging_remove_request(req); + remaining--; } *msc_p = paged_from_msc; *reasons_p = reasons; - - return count; } /* Remove all paging requests, for specific reasons only. */ -int paging_request_cancel(struct bsc_subscr *bsub, enum bsc_paging_reason reasons) +void paging_request_cancel(struct bsc_subscr *bsub, enum bsc_paging_reason reasons) { - struct gsm_bts *bts; - int count = 0; - - llist_for_each_entry(bts, &bsc_gsmnet->bts_list, list) { - struct gsm_paging_request *req, *req2; + struct gsm_paging_request *req, *req2; + OSMO_ASSERT(bsub); - paging_init_if_needed(bts); + /* Avoid accessing bsub after reaching 0 active_paging_request_len, + * since it could be freed during put(): */ + unsigned remaining = bsub->active_paging_requests_len; - llist_for_each_entry_safe(req, req2, &bts->paging.pending_requests, entry) { - if (req->bsub != bsub) - continue; - if (!(req->reason & reasons)) - continue; - LOG_BTS(bts, DPAG, LOGL_DEBUG, "Cancel paging %s\n", bsc_subscr_name(bsub)); - paging_remove_request(&bts->paging, req); - count++; + llist_for_each_entry_safe(req, req2, &bsub->active_paging_requests, bsub_entry) { + if (!(req->reason & reasons)) + continue; + LOG_PAGING_BTS(req, req->bts, DPAG, LOGL_DEBUG, "Cancel paging reasons=0x%x\n", + reasons); + if (req->reason & ~reasons) { + /* Other reasons are active, simply drop the reasons from func arg: */ + req->reason &= ~reasons; + continue; } + /* No reason to keep the paging, remove it: */ + paging_remove_request(req); + remaining--; + if (remaining == 0) + break; } - return count; } /*! Update the BTS paging buffer slots on given BTS */ void paging_update_buffer_space(struct gsm_bts *bts, uint16_t free_slots) { - paging_init_if_needed(bts); - - osmo_timer_del(&bts->paging.credit_timer); - bts->paging.available_slots = free_slots; - paging_schedule_if_needed(&bts->paging); + LOG_BTS(bts, DPAG, LOGL_DEBUG, "Rx CCCH Load Indication from BTS (available_slots %u -> %u)\n", + bts->paging.available_slots, free_slots); + paging_set_available_slots(bts, free_slots); + /* Re-arm credit_timer if needed */ + if (trx_is_usable(bts->c0)) { + paging_schedule_if_needed(&bts->paging); + osmo_timer_schedule(&bts->paging.credit_timer, + bts_no_ccch_load_ind_timeout_sec(bts), 0); + } } /*! Count the number of pending paging requests on given BTS */ -unsigned int paging_pending_requests_nr(struct gsm_bts *bts) +unsigned int paging_pending_requests_nr(const struct gsm_bts *bts) { - unsigned int requests = 0; - struct gsm_paging_request *req; - - paging_init_if_needed(bts); - - llist_for_each_entry(req, &bts->paging.pending_requests, entry) - ++requests; - - return requests; + return bts->paging.initial_req_list_len + bts->paging.retrans_req_list_len; } /*! Flush all paging requests at a given BTS for a given MSC (or NULL if all MSC should be flushed). */ @@ -510,19 +708,22 @@ void paging_flush_bts(struct gsm_bts *bts, struct bsc_msc_data *msc) { struct gsm_paging_request *req, *req2; int num_cancelled = 0; + int i; - paging_init_if_needed(bts); + struct llist_head *lists[] = { &bts->paging.initial_req_list, &bts->paging.retrans_req_list }; - llist_for_each_entry_safe(req, req2, &bts->paging.pending_requests, entry) { - if (msc && req->msc != msc) - continue; - /* now give up the data structure */ - LOG_BTS(bts, DPAG, LOGL_DEBUG, "Stop paging %s (flush)\n", bsc_subscr_name(req->bsub)); - paging_remove_request(&bts->paging, req); - num_cancelled++; + for (i = 0; i < ARRAY_SIZE(lists); i++) { + llist_for_each_entry_safe(req, req2, lists[i], entry) { + if (msc && req->msc != msc) + continue; + /* now give up the data structure */ + LOG_PAGING_BTS(req, bts, DPAG, LOGL_DEBUG, "Stop paging (flush)\n"); + paging_remove_request(req); + num_cancelled++; + } } - rate_ctr_add(&bts->bts_ctrs->ctr[BTS_CTR_PAGING_MSC_FLUSH], num_cancelled); + rate_ctr_add(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_CTR_PAGING_MSC_FLUSH), num_cancelled); } /*! Flush all paging requests issued by \a msc on any BTS in \a net */ @@ -533,3 +734,115 @@ void paging_flush_network(struct gsm_network *net, struct bsc_msc_data *msc) llist_for_each_entry(bts, &net->bts_list, list) paging_flush_bts(bts, msc); } + +/* Shim to avoid problems when compiling against libosmocore <= 1.7.0, since + * gsm0502_get_n_pag_blocks() was not declared const despite being readonly. Once + * osmo-bsc depends on libosmocore > 1.7.0, this shim can be dropped. */ +static inline unsigned int _gsm0502_get_n_pag_blocks(const struct gsm48_control_channel_descr *chan_desc) +{ + return gsm0502_get_n_pag_blocks((struct gsm48_control_channel_descr *)chan_desc); +} + +/*! Estimate available_slots credit over a time period, used when below CCCH Load Indication Threshold */ +uint16_t paging_estimate_available_slots(const struct gsm_bts *bts, unsigned int time_span_s) +{ + unsigned int n_pag_blocks = _gsm0502_get_n_pag_blocks(&bts->si_common.chan_desc); + uint16_t available_slots = n_pag_blocks * time_span_s * 1000000 / GSM51_MFRAME_DURATION_us; + LOG_BTS(bts, DPAG, LOGL_DEBUG, "Estimated %u paging available_slots over %u seconds\n", + available_slots, time_span_s); + return available_slots; +} + +/*! Conservative estimate of time needed by BTS to schedule a number of paging + * requests (num_reqs), based on current load at the BSC queue (doesn't take into + * account BTs own buffer) */ +static unsigned int paging_estimate_delay_us(struct gsm_bts *bts, unsigned int num_reqs, + unsigned int num_reqs_same_pgroup) +{ + unsigned int n_pag_blocks, n_mframes, time_us = 0; + + n_pag_blocks = _gsm0502_get_n_pag_blocks(&bts->si_common.chan_desc); + + /* First of all, we need to extend the timeout in relation to the amount + * of paging requests in the BSC queue. In here we don't care about the + * paging group, because they are mixed in the same queue. If we don't + * take this into account, it could happen that if lots of requests are + * received at the BSC (from MSC) around the same time, they could time + * out in the BSC queue before arriving at the BTS. We already account of + * same-paging-group ones further below, so don't take them into account + * here: */ + unsigned int num_reqs_other_groups = num_reqs - num_reqs_same_pgroup; + time_us += ((num_reqs_other_groups * GSM51_MFRAME_DURATION_us) + (n_pag_blocks - 1)) / n_pag_blocks; + + /* Now we extend the timeout based on the amount of requests of the same + * paging group before the present one: */ + n_mframes = (num_reqs_same_pgroup + (n_pag_blocks - 1)) / n_pag_blocks; + time_us += n_mframes * GSM51_MFRAME_DURATION_us; + /* the multiframes are not consecutive for a paging group, let's add the spacing between: */ + if (n_mframes > 1) { + unsigned int bs_pa_mfrms = (bts->si_common.chan_desc.bs_pa_mfrms + 2); + time_us += (n_mframes - 1) * bs_pa_mfrms * GSM51_MFRAME_DURATION_us; + } + return time_us; +} + +/* Callback function to be called every time we receive a signal from NM */ +static int nm_sig_cb(unsigned int subsys, unsigned int signal, + void *handler_data, void *signal_data) +{ + struct nm_running_chg_signal_data *nsd; + struct gsm_bts *bts; + struct gsm_bts_trx *trx; + unsigned int load_ind_timeout; + uint16_t estimated_slots; + + if (signal != S_NM_RUNNING_CHG) + return 0; + + nsd = signal_data; + bts = nsd->bts; + + switch (nsd->obj_class) { + case NM_OC_RADIO_CARRIER: + trx = (struct gsm_bts_trx *)nsd->obj; + break; + case NM_OC_BASEB_TRANSC: + trx = gsm_bts_bb_trx_get_trx((struct gsm_bts_bb_trx *)nsd->obj); + break; + default: + return 0; + } + + /* We only care about state changes of C0. */ + if (trx != trx->bts->c0) + return 0; + + if (nsd->running) { + if (trx_is_usable(trx)) { + LOG_BTS(bts, DPAG, LOGL_INFO, "C0 becomes available for paging\n"); + /* Fill in initial credit */ + load_ind_timeout = bts_no_ccch_load_ind_timeout_sec(bts); + estimated_slots = paging_estimate_available_slots(bts, load_ind_timeout); + paging_set_available_slots(bts, estimated_slots); + /* Start scheduling credit_timer */ + osmo_timer_schedule(&bts->paging.credit_timer, + bts_no_ccch_load_ind_timeout_sec(bts), 0); + /* work_timer will be started when new paging requests arrive. */ + } + } else { + /* If credit timer was not pending it means C0 was already unavailable before (rcarrier||bbtransc) */ + if (osmo_timer_pending(&bts->paging.credit_timer)) { + LOG_BTS(bts, DPAG, LOGL_INFO, "C0 becomes unavailable for paging\n"); + /* Note: flushing will osmo_timer_del(&bts->paging.work_timer) when queue becomes empty */ + paging_flush_bts(bts, NULL); + osmo_timer_del(&bts->paging.credit_timer); + } + } + return 0; +} + +/* To be called once at startup of the process: */ +void paging_global_init(void) +{ + osmo_signal_register_handler(SS_NM, nm_sig_cb, NULL); +} |