fixeria has submitted this change. (
https://gerrit.osmocom.org/c/osmo-bts/+/42911?usp=email )
Change subject: common: stop buffering UL measurements when SACCH is deactivated
......................................................................
common: stop buffering UL measurements when SACCH is deactivated
When the BSC sends RSL DEACT SACCH, the per-SACCH UL measurement drain
stops (it runs on SACCH timing), but the producer in lchan_new_ul_meas()
keeps appending the measurement contributions from every received
TCH/SDCCH burst. After one SACCH period (104 frames) the 104-slot
uplink measurement buffer fills up, yielding a flood of:
NOTICE measurement.c:336 no space for uplink measurement, num_ul_meas=104
Add a bool sacch_active flag to gsm_lchan, set to true in the common
l1sap_chan_act() and clear in l1sap_chan_deact_sacch(). Guard
lchan_new_ul_meas() with this flag so that measurements are silently
discarded while SACCH is inactive - there is nothing to drain the
buffer and no SACCH channel on which to report the results to the BSC.
Change-Id: I3943c788cab5d2411b06ac681d4d412852bac0a7
AI-Assisted: yes (Claude)
---
M include/osmo-bts/lchan.h
M src/common/l1sap.c
M src/common/measurement.c
M tests/meas/meas_test.c
4 files changed, 11 insertions(+), 0 deletions(-)
Approvals:
laforge: Looks good to me, but someone else must approve
pespin: Looks good to me, but someone else must approve
fixeria: Looks good to me, approved
osmith: Looks good to me, but someone else must approve
Jenkins Builder: Verified
diff --git a/include/osmo-bts/lchan.h b/include/osmo-bts/lchan.h
index 071197d..909768d 100644
--- a/include/osmo-bts/lchan.h
+++ b/include/osmo-bts/lchan.h
@@ -210,6 +210,7 @@
* want_dl_sacch_active indicates whether dl SACCH should be activated
on CHAN ACT.
*/
bool want_dl_sacch_active;
+ bool ul_sacch_active; /* UL SACCH measurements active (cleared by RSL
DEACT SACCH) */
/* Number of different GsmL1_Sapi_t used in osmo_bts_sysmo is 23.
* Currently we don't share these headers so this is a magic number. */
diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index f11bb2c..e0d0bba 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -3013,6 +3013,8 @@
lchan->ts->vamos.is_shadow ?
"-shadow" : "");
OSMO_ASSERT(rc == 0);
}
+
+ lchan->ul_sacch_active = true;
return 0;
}
@@ -3055,6 +3057,8 @@
LOGPLCHAN(lchan, DL1C, LOGL_INFO, "Deactivating SACCH on channel %s\n",
rsl_chan_nr_str(chan_nr));
+ lchan->ul_sacch_active = false;
+
return l1sap_chan_act_dact_modify(trx, chan_nr, PRIM_INFO_DEACTIVATE,
1);
}
diff --git a/src/common/measurement.c b/src/common/measurement.c
index afbdc84..8bb3e6e 100644
--- a/src/common/measurement.c
+++ b/src/common/measurement.c
@@ -332,6 +332,11 @@
gsm_lchans_name(lchan->state),
lchan->meas.num_ul_meas, fn_mod);
}
+ /* No point buffering measurements when SACCH is deactivated: the drain
+ * runs on SACCH timing, so the buffer would fill up and overflow. */
+ if (!lchan->ul_sacch_active)
+ return 0;
+
if (lchan->meas.num_ul_meas >= ARRAY_SIZE(lchan->meas.uplink)) {
LOGPLCFN(lchan, fn, DMEAS, LOGL_NOTICE,
"no space for uplink measurement, num_ul_meas=%d,
fn_mod=%u\n", lchan->meas.num_ul_meas,
diff --git a/tests/meas/meas_test.c b/tests/meas/meas_test.c
index 4c93421..d2b6199 100644
--- a/tests/meas/meas_test.c
+++ b/tests/meas/meas_test.c
@@ -68,6 +68,7 @@
static void reset_lchan_meas(struct gsm_lchan *lchan)
{
lchan->state = LCHAN_S_ACTIVE;
+ lchan->ul_sacch_active = true;
memset(&lchan->meas, 0, sizeof(lchan->meas));
}
--
To view, visit https://gerrit.osmocom.org/c/osmo-bts/+/42911?usp=email
To unsubscribe, or for help writing mail filters, visit
https://gerrit.osmocom.org/settings?usp=email
Gerrit-MessageType: merged
Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Change-Id: I3943c788cab5d2411b06ac681d4d412852bac0a7
Gerrit-Change-Number: 42911
Gerrit-PatchSet: 3
Gerrit-Owner: fixeria <[email protected]>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: fixeria <[email protected]>
Gerrit-Reviewer: laforge <[email protected]>
Gerrit-Reviewer: osmith <[email protected]>
Gerrit-Reviewer: pespin <[email protected]>
