agch: Merge IMM.ASS.REJ if possible when enqueueing

This patch implements merging of IMMEDIATE ASSIGN REJECT messages as
sugegsted in GSM 08.58, 5.7. When a new IMM.ASS.REJ is to be appended
to the AGCH queue and the last message in that queue is of the same
type, the individual entries (up to 4 per message) of both messages
are extracted, combined and stored back. If there are less than 5
entries all entries fit into the old message and the new one is
discarded. Otherwise, the old message will contain 4 entries and the
remaining ones are stored into the new one which is then appended to
the queue.

Ticket: #224
Sponsored-by: On-Waves ehf
This commit is contained in:
Jacob Erlbeck 2014-02-20 18:45:45 +01:00 committed by Holger Hans Peter Freyther
parent 0148d4e7d5
commit 46d5bfb298
2 changed files with 141 additions and 2 deletions

View File

@ -306,10 +306,138 @@ void bts_update_agch_max_queue_length(struct gsm_bts *bts)
btsb->agch_max_queue_length);
}
#define REQ_REFS_PER_IMM_ASS_REJ 4
static int store_imm_ass_rej_refs(struct gsm48_imm_ass_rej *rej,
struct gsm48_req_ref *req_refs,
uint8_t *wait_inds,
int count)
{
switch (count) {
case 0:
/* TODO: Warning ? */
return 0;
default:
count = 4;
rej->req_ref4 = req_refs[3];
rej->wait_ind4 = wait_inds[3];
/* fall through */
case 3:
rej->req_ref3 = req_refs[2];
rej->wait_ind3 = wait_inds[2];
/* fall through */
case 2:
rej->req_ref2 = req_refs[1];
rej->wait_ind2 = wait_inds[1];
/* fall through */
case 1:
rej->req_ref1 = req_refs[0];
rej->wait_ind1 = wait_inds[0];
break;
}
switch (count) {
case 1:
rej->req_ref2 = req_refs[0];
rej->wait_ind2 = wait_inds[0];
/* fall through */
case 2:
rej->req_ref3 = req_refs[0];
rej->wait_ind3 = wait_inds[0];
/* fall through */
case 3:
rej->req_ref4 = req_refs[0];
rej->wait_ind4 = wait_inds[0];
/* fall through */
default:
break;
}
return count;
}
static int extract_imm_ass_rej_refs(struct gsm48_imm_ass_rej *rej,
struct gsm48_req_ref *req_refs,
uint8_t *wait_inds)
{
int count = 0;
req_refs[count] = rej->req_ref1;
wait_inds[count] = rej->wait_ind1;
count++;
if (memcmp(&rej->req_ref1, &rej->req_ref2, sizeof(rej->req_ref2))) {
req_refs[count] = rej->req_ref2;
wait_inds[count] = rej->wait_ind2;
count++;
}
if (memcmp(&rej->req_ref1, &rej->req_ref3, sizeof(rej->req_ref3)) &&
memcmp(&rej->req_ref2, &rej->req_ref3, sizeof(rej->req_ref3))) {
req_refs[count] = rej->req_ref3;
wait_inds[count] = rej->wait_ind3;
count++;
}
if (memcmp(&rej->req_ref1, &rej->req_ref4, sizeof(rej->req_ref4)) &&
memcmp(&rej->req_ref2, &rej->req_ref4, sizeof(rej->req_ref4)) &&
memcmp(&rej->req_ref3, &rej->req_ref4, sizeof(rej->req_ref4))) {
req_refs[count] = rej->req_ref4;
wait_inds[count] = rej->wait_ind4;
count++;
}
return count;
}
static int try_merge_imm_ass_rej(struct gsm48_imm_ass_rej *old_rej,
struct gsm48_imm_ass_rej *new_rej)
{
struct gsm48_req_ref req_refs[2 * REQ_REFS_PER_IMM_ASS_REJ];
uint8_t wait_inds[2 * REQ_REFS_PER_IMM_ASS_REJ];
int count = 0;
int stored = 0;
if (new_rej->msg_type != GSM48_MT_RR_IMM_ASS_REJ)
return 0;
if (old_rej->msg_type != GSM48_MT_RR_IMM_ASS_REJ)
return 0;
/* GSM 08.58, 5.7
* -> The BTS may combine serveral IMM.ASS.REJ messages
* -> Identical request refs in one message may be squeezed
*
* GSM 04.08, 9.1.20.2
* -> Request ref and wait ind are duplicated to fill the message
*/
/* Extract all entries */
count = extract_imm_ass_rej_refs(old_rej,
&req_refs[count], &wait_inds[count]);
if (count == REQ_REFS_PER_IMM_ASS_REJ)
return 0;
count += extract_imm_ass_rej_refs(new_rej,
&req_refs[count], &wait_inds[count]);
/* Store entries into old message */
stored = store_imm_ass_rej_refs(old_rej,
&req_refs[stored], &wait_inds[stored],
count);
count -= stored;
if (count == 0)
return 1;
/* Store remaining entries into new message */
stored += store_imm_ass_rej_refs(new_rej,
&req_refs[stored], &wait_inds[stored],
count);
return 0;
}
int bts_agch_enqueue(struct gsm_bts *bts, struct msgb *msg)
{
struct gsm_bts_role_bts *btsb = bts_role_bts(bts);
int hard_limit = 1000;
struct gsm48_imm_ass_rej *imm_ass_cmd = msgb_l3(msg);
if (btsb->agch_queue_length > hard_limit) {
LOGP(DSUM, LOGL_ERROR,
@ -322,6 +450,17 @@ int bts_agch_enqueue(struct gsm_bts *bts, struct msgb *msg)
return -ENOMEM;
}
if (btsb->agch_queue_length > 0) {
struct msgb *last_msg =
llist_entry(btsb->agch_queue.prev, struct msgb, list);
struct gsm48_imm_ass_rej *last_imm_ass_rej = msgb_l3(last_msg);
if (try_merge_imm_ass_rej(last_imm_ass_rej, imm_ass_cmd)) {
btsb->agch_queue_merged_msgs++;
return 0;
}
}
msgb_enqueue(&btsb->agch_queue, msg);
btsb->agch_queue_length++;

View File

@ -18,6 +18,6 @@ T BCCH slots
32 83 28 83 83 83
50 28 14 28 28 28
Testing AGCH messages queue handling.
AGCH filled: count 720, imm.ass 80, imm.ass.rej 640 (refs 640), queue limit 32, occupied 720, dropped 0, merged 0, rejected 0, ag-res 0, non-res 0
AGCH drained: multiframes 33, imm.ass 80, imm.ass.rej 17 (refs 17), queue limit 32, occupied 0, dropped 624, merged 0, rejected 0, ag-res 32, non-res 64
AGCH filled: count 720, imm.ass 80, imm.ass.rej 640 (refs 640), queue limit 32, occupied 240, dropped 0, merged 480, rejected 0, ag-res 0, non-res 0
AGCH drained: multiframes 32, imm.ass 80, imm.ass.rej 12 (refs 48), queue limit 32, occupied 0, dropped 148, merged 480, rejected 0, ag-res 31, non-res 61
Success