Change in osmo-bsc[master]: paging: Decouple retransmit period from regular worker interval

pespin has submitted this change. ( https://gerrit.osmocom.org/c/osmo-bsc/+/27944 ) Change subject: paging: Decouple retransmit period from regular worker interval ...................................................................... paging: Decouple retransmit period from regular worker interval Before this patch, on each BTS a 500ms timer was used to schedule some work, sending up to 20 paging requests verytime. This means, however, for an initial paging request it may take up to 500ms delay to be scheduled to the BTS, which is huge. While we still want to maintain this 500ms interval for retransmits, it doesn't make sense to wait that much for other cases. It's far better sending less requests (10 instead of 20) every half time (250ms instead of 500ms), since it will spread the load and paging more over time, allowing for other work to be done in the middle. Change-Id: I7a1297452cc4734b6ee8c38fb94cf32f38d57c3d --- M include/osmocom/bsc/paging.h M src/osmo-bsc/paging.c 2 files changed, 33 insertions(+), 2 deletions(-) Approvals: Jenkins Builder: Verified fixeria: Looks good to me, but someone else must approve laforge: Looks good to me, approved diff --git a/include/osmocom/bsc/paging.h b/include/osmocom/bsc/paging.h index 2102e04..d9fd501 100644 --- a/include/osmocom/bsc/paging.h +++ b/include/osmocom/bsc/paging.h @@ -82,6 +82,8 @@ /* How often did we ask the BTS to page? */ int attempts; + /* Timestamp of last time the subscriber was paged */ + struct timespec last_attempt_ts; /* MSC that has issued this paging */ struct bsc_msc_data *msc; diff --git a/src/osmo-bsc/paging.c b/src/osmo-bsc/paging.c index 3da5f18..9bc0105 100644 --- a/src/osmo-bsc/paging.c +++ b/src/osmo-bsc/paging.c @@ -59,7 +59,19 @@ void *tall_paging_ctx = NULL; /* How many paging requests to Tx on RSL at max before going back to main loop */ -#define MAX_PAGE_REQ_PER_ITER 20 +#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, +}; /* * Kill one paging request update the internal list... @@ -185,6 +197,7 @@ struct gsm_paging_request *request, *initial_request; unsigned int num_paged = 0; struct gsm_bts *bts = paging_bts->bts; + struct timespec now, retrans_ts; /* * Determine if the pending_requests list is empty and @@ -199,6 +212,8 @@ if (!bts->c0->rsl_link_primary) goto sched_next_iter; + osmo_clock_gettime(CLOCK_MONOTONIC, &now); + /* do while loop: Try send at most first MAX_PAGE_REQ_PER_ITER paging * requests (or before if there are no more available slots). Since * transmitted requests are re-appended at the end of the list, we check @@ -223,9 +238,23 @@ goto sched_next_iter; } + /* If we reach around back of the queue (retransmitions), check + * if time to retransmit has elapsed. Otherwise, wait until its + * time to retransmit. */ + if (request->attempts > 0) { + timespecadd(&request->last_attempt_ts, &retrans_period, &retrans_ts); + if (timespeccmp(&now, &retrans_ts, <)) { + struct timespec tdiff; + timespecsub(&retrans_ts, &now, &tdiff); + osmo_timer_schedule(&paging_bts->work_timer, tdiff.tv_sec, tdiff.tv_nsec / 1000); + return; + } + } + /* handle the paging request now */ page_ms(request); paging_bts->available_slots--; + request->last_attempt_ts = now; request->attempts++; num_paged++; @@ -237,7 +266,7 @@ /* Once done iterating, prepare next scheduling: */ sched_next_iter: - osmo_timer_schedule(&paging_bts->work_timer, 0, 500000); + osmo_timer_schedule(&paging_bts->work_timer, initial_period.tv_sec, initial_period.tv_nsec / 1000); } static void paging_worker(void *data) 3 is the latest approved patch-set. No files were changed between the latest approved patch-set and the submitted one. -- To view, visit https://gerrit.osmocom.org/c/osmo-bsc/+/27944 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: osmo-bsc Gerrit-Branch: master Gerrit-Change-Id: I7a1297452cc4734b6ee8c38fb94cf32f38d57c3d Gerrit-Change-Number: 27944 Gerrit-PatchSet: 4 Gerrit-Owner: pespin &lt;pespin(a)sysmocom.de&gt; Gerrit-Reviewer: Jenkins Builder Gerrit-Reviewer: fixeria &lt;vyanitskiy(a)sysmocom.de&gt; Gerrit-Reviewer: laforge &lt;laforge(a)osmocom.org&gt; Gerrit-Reviewer: pespin &lt;pespin(a)sysmocom.de&gt; Gerrit-MessageType: merged