pespin has uploaded this change for review. (
https://gerrit.osmocom.org/c/osmo-bsc/+/30370 )
Change subject: paging: Optimize retrieving number of request per paging group
......................................................................
paging: Optimize retrieving number of request per paging group
This patch caches the counts of initial paging requests for each paging
group. This count is needed to estimate T3113 when a new incoming paging
request is received and it has to be inserted into the queue.
With this there's no need to traverse the whole initial_req_list every
time a new incoming paging request is receiving, potentially saving lots
of iteration and hence lots of CPU when the queue is long.
Related: SYS#6200
Change-Id: I6994127827d120a0b4dd3de51e1ddde39f2fe531
---
M include/osmocom/bsc/paging.h
M src/osmo-bsc/paging.c
2 files changed, 17 insertions(+), 20 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/70/30370/1
diff --git a/include/osmocom/bsc/paging.h b/include/osmocom/bsc/paging.h
index b10c398..15eb49e 100644
--- a/include/osmocom/bsc/paging.h
+++ b/include/osmocom/bsc/paging.h
@@ -61,6 +61,9 @@
*/
#define PAGING_THRESHOLD_X3113_DEFAULT_SEC 60
+#define MAX_PAGING_BLOCKS_CCCH 9
+#define MAX_BS_PA_MFRMS 9
+
struct bsc_paging_params {
enum bsc_paging_reason reason;
struct bsc_msc_data *msc;
@@ -117,6 +120,9 @@
/* Number of requests in pending_requests_len */
unsigned int retrans_req_list_len;
+ /* Number of requests in initial_req_list, indexed by pgroup. */
+ unsigned int initial_req_pgroup_counts[MAX_PAGING_BLOCKS_CCCH *
MAX_BS_PA_MFRMS];
+
struct gsm_bts *bts;
struct osmo_timer_list work_timer;
diff --git a/src/osmo-bsc/paging.c b/src/osmo-bsc/paging.c
index 627d7b6..8a6195c 100644
--- a/src/osmo-bsc/paging.c
+++ b/src/osmo-bsc/paging.c
@@ -88,10 +88,12 @@
osmo_timer_del(&req->T3113);
llist_del(&req->entry);
- if (req->attempts == 0)
+ if (req->attempts == 0) {
bts_pag_st->initial_req_list_len--;
- else
+ 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);
@@ -261,6 +263,7 @@
num_paged++;
/* Since request was 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++;
}
@@ -498,9 +501,8 @@
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);
- unsigned int reqs_before = 0, reqs_before_same_pgroup = 0;
- uint8_t pgroup = gsm0502_calc_paging_group(&bts->si_common.chan_desc,
-
str_to_imsi(params->bsub->imsi));
+ uint8_t pgroup;
+ unsigned int reqs_before, reqs_before_same_pgroup;
rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs,
BTS_CTR_PAGING_ATTEMPTED));
@@ -525,21 +527,9 @@
paging_remove_request(first_retrans_req);
}
- /* The incoming new req will be stored in initial_req_list giving
higher prio
- * to it over retransmissions. This avoids new subscribers being paged
to
- * be delayed if the paging queue is full due to a lot of
retranmissions.
- * Retranmissions usually mean MS are not reachable/available, so the
- * rationale here is to prioritize new subs which may be available.
- *
- * Count initial reqs already stored in initial_req_list, since those
- * will be scheduled for transmission before current incoming req and
- need to be taken into account when calculating T3113 for it.
- */
- llist_for_each_entry(req, &bts_entry->initial_req_list, entry) {
- reqs_before++;
- if (req->pgroup == pgroup)
- reqs_before_same_pgroup++;
- }
+ 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);
@@ -554,6 +544,7 @@
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);
--
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Gerrit-Project: osmo-bsc
Gerrit-Branch: master
Gerrit-Change-Id: I6994127827d120a0b4dd3de51e1ddde39f2fe531
Gerrit-Change-Number: 30370
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <[email protected]>
Gerrit-MessageType: newchange
