Hello Jenkins Builder,

I'd like you to reexamine a change. Please visit

https://gerrit.osmocom.org/c/osmo-bsc/+/31866

to look at the new patch set (#2).

Change subject: Optimize subscr_conns lookup ......................................................................

Optimize subscr_conns lookup

It was found that, on a busy osmo-bsc (>1000 concurrent calls spread over several BTS), the CPU consumption looking up for gsm_subscriber_conn based on SCCP conn_id can take a considerable amount of time (>5% of osmo-bsc already taking 70% of the CPU time on the core it is running on).

The huge CPU consumption happens because a linear search is done (llist) over the entire list of SCCP connections every time an SCCP message is handled.

In order to optimize this lookup, this patch introduces a new struct bsc_sccp_inst which becomes associated to the libosmo-sccp osmo_sccp_instance. Each of this strucs maintains an rbtree of gsm_subscriber_conn ordered by conn_id. As a result algorithmic complexity adds O(log(N)) during insert, lookup and delete of SCCP conns, but gets rid of O(N) previous lookup. As a plus, finding a new conn_id now takes generally O(log(N)), while before it used to take O(N).

Related: SYS#6200 Change-Id: I667d3ec1dad0ab7bc0fa4799d9611f3a914d07e5 --- M TODO-RELEASE M include/osmocom/bsc/gsm_data.h M src/osmo-bsc/bsc_sccp.c M src/osmo-bsc/bsc_subscr_conn_fsm.c M src/osmo-bsc/lb.c M src/osmo-bsc/osmo_bsc_sigtran.c 6 files changed, 183 insertions(+), 101 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/66/31866/2