pespin has uploaded this change for review. (
https://gerrit.osmocom.org/c/osmo-bts/+/29034 )
Change subject: Avoid counting lchan->dl_tch_queue length every time a msg is
enqueued
......................................................................
Avoid counting lchan->dl_tch_queue length every time a msg is enqueued
The queue_limit_to method iterates the entire list of messages every
time a new message is added. Let's use msgb_{enqueue,dequeue}_count()
APIs to do that in constant time. It is true that since the queue is
limited to 1, there's usually at most 1 item in the queue so it's not a
real problem. However, when we add Osmux in the future, we may need to
tweak the amount of messages which can be in the list, due to Osmux
batching mechansim which may be more bursty sometimes.
In any case, this change doesn't make things worse for sure.
The patch also takes the chance to group the queue_limit_to + enqueue
into one function to avoid having the code spread several times.
Change-Id: I61818a3bb521c27bd21a8b6fa70581d27638ec9b
---
M include/osmo-bts/lchan.h
M src/common/l1sap.c
M src/common/lchan.c
3 files changed, 16 insertions(+), 19 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/34/29034/1
diff --git a/include/osmo-bts/lchan.h b/include/osmo-bts/lchan.h
index c86acb0..64b7efa 100644
--- a/include/osmo-bts/lchan.h
+++ b/include/osmo-bts/lchan.h
@@ -191,6 +191,7 @@
uint8_t sapis_ul[23];
struct lapdm_channel lapdm_ch;
struct llist_head dl_tch_queue;
+ unsigned int dl_tch_queue_len;
struct {
/* bitmask of all SI that are present/valid in si_buf */
uint32_t valid;
diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index b74fd5a..d7b7abf 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -153,17 +153,16 @@
}
/*! limit number of queue entries to %u; drops any surplus messages */
-static void queue_limit_to(const char *prefix, struct llist_head *queue,
unsigned int limit)
+static void lchan_dl_tch_queue_enqueue(struct gsm_lchan *lchan, struct msgb
*msg, unsigned int limit)
{
- unsigned int count = llist_count(queue);
-
- if (count > limit)
- LOGP(DL1P, LOGL_NOTICE, "%s: freeing %d queued frames\n",
prefix, count-limit);
- while (count > limit) {
- struct msgb *tmp = msgb_dequeue(queue);
+ if (lchan->dl_tch_queue_len > limit)
+ LOGPLCHAN(lchan, DL1P, LOGL_NOTICE, "freeing %d queued
frames\n",
+ lchan->dl_tch_queue_len - limit);
+ while (lchan->dl_tch_queue_len > limit) {
+ struct msgb *tmp = msgb_dequeue_count(&lchan->dl_tch_queue,
&lchan->dl_tch_queue_len);
msgb_free(tmp);
- count--;
}
+ msgb_enqueue_count(&lchan->dl_tch_queue, msg, &lchan->dl_tch_queue_len);
}
/* allocate a msgb containing a osmo_phsap_prim + optional l2 data
@@ -915,7 +914,7 @@
uint8_t *p;
/* de-queue response message (loopback) */
- loop_msg = msgb_dequeue(&lchan->dl_tch_queue);
+ loop_msg = msgb_dequeue_count(&lchan->dl_tch_queue,
&lchan->dl_tch_queue_len);
if (!loop_msg) {
LOGPGT(DL1P, LOGL_NOTICE, tm, "%s: no looped PDTCH message,
sending empty\n",
gsm_lchan_name(lchan));
@@ -1305,7 +1304,7 @@
lchan->abis_ip.rtp_socket->rx_user_ts += GSM_RTP_DURATION;
}
/* get a msgb from the dl_tx_queue */
- resp_msg = msgb_dequeue(&lchan->dl_tch_queue);
+ resp_msg = msgb_dequeue_count(&lchan->dl_tch_queue,
&lchan->dl_tch_queue_len);
if (!resp_msg) {
DEBUGPGT(DL1P, &g_time, "%s DL TCH Tx queue underrun\n",
gsm_lchan_name(lchan));
resp_l1sap = &empty_l1sap;
@@ -1500,8 +1499,7 @@
/* we are in loopback mode (for BER testing)
* mode and need to enqeue the frame to be
* returned in downlink */
- queue_limit_to(gsm_lchan_name(lchan),
&lchan->dl_tch_queue, 1);
- msgb_enqueue(&lchan->dl_tch_queue, msg);
+ lchan_dl_tch_queue_enqueue(lchan, msg, 1);
/* Return 1 to signal that we're still using msg
* and it should not be freed */
@@ -1622,10 +1620,8 @@
msg->data, msg->len, fn_ms_adj(fn, lchan),
lchan->rtp_tx_marker);
/* if loopback is enabled, also queue received RTP data */
if (lchan->loopback) {
- /* make sure the queue doesn't get too long */
- queue_limit_to(gsm_lchan_name(lchan),
&lchan->dl_tch_queue, 1);
- /* add new frame to queue */
- msgb_enqueue(&lchan->dl_tch_queue, msg);
+ /* add new frame to queue, make sure the queue doesn't
get too long */
+ lchan_dl_tch_queue_enqueue(lchan, msg, 1);
/* Return 1 to signal that we're still using msg and it
should not be freed */
return 1;
}
@@ -1914,9 +1910,7 @@
rtpmsg_ts(msg) = timestamp;
/* make sure the queue doesn't get too long */
- queue_limit_to(gsm_lchan_name(lchan), &lchan->dl_tch_queue, 1);
-
- msgb_enqueue(&lchan->dl_tch_queue, msg);
+ lchan_dl_tch_queue_enqueue(lchan, msg, 1);
}
static int l1sap_chan_act_dact_modify(struct gsm_bts_trx *trx, uint8_t chan_nr,
diff --git a/src/common/lchan.c b/src/common/lchan.c
index 6f344e2..83d20da 100644
--- a/src/common/lchan.c
+++ b/src/common/lchan.c
@@ -132,6 +132,7 @@
INIT_LLIST_HEAD(&lchan->sapi_cmds);
INIT_LLIST_HEAD(&lchan->dl_tch_queue);
+ lchan->dl_tch_queue_len = 0;
}
void gsm_lchan_name_update(struct gsm_lchan *lchan)
@@ -638,4 +639,5 @@
osmo_rtp_socket_free(lchan->abis_ip.rtp_socket);
lchan->abis_ip.rtp_socket = NULL;
msgb_queue_flush(&lchan->dl_tch_queue);
+ lchan->dl_tch_queue_len = 0;
}
--
To view, visit https://gerrit.osmocom.org/c/osmo-bts/+/29034
To unsubscribe, or for help writing mail filters, visit
https://gerrit.osmocom.org/settings
Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Change-Id: I61818a3bb521c27bd21a8b6fa70581d27638ec9b
Gerrit-Change-Number: 29034
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <pes...@sysmocom.de>
Gerrit-MessageType: newchange
