cxgbe(4): Track the number of received frames separately from the number

of descriptors processed.  Add the ability to gather a certain maximum
number of frames in the driver's rx before waking up netmap rx.  If
there aren't enough frames then netmap rx will be woken up as usual.

hw.cxgbe.nm_rx_nframes

Sponsored by:	Chelsio Communications
This commit is contained in:
Navdeep Parhar 2018-06-15 21:23:03 +00:00
parent a463bac8dd
commit 31f494cdf5

View File

@ -72,6 +72,10 @@ int rx_ndesc = 256;
SYSCTL_INT(_hw_cxgbe, OID_AUTO, nm_rx_ndesc, CTLFLAG_RWTUN,
&rx_ndesc, 0, "# of rx descriptors after which the hw cidx is updated.");
int rx_nframes = 64;
SYSCTL_INT(_hw_cxgbe, OID_AUTO, nm_rx_nframes, CTLFLAG_RWTUN,
&rx_nframes, 0, "max # of frames received before waking up netmap rx.");
int holdoff_tmr_idx = 2;
SYSCTL_INT(_hw_cxgbe, OID_AUTO, nm_holdoff_tmr_idx, CTLFLAG_RWTUN,
&holdoff_tmr_idx, 0, "Holdoff timer index for netmap rx queues.");
@ -938,10 +942,12 @@ t4_nm_intr(void *arg)
struct iq_desc *d = &nm_rxq->iq_desc[nm_rxq->iq_cidx];
const void *cpl;
uint32_t lq;
u_int n = 0, work = 0;
u_int work = 0;
uint8_t opcode;
uint32_t fl_cidx = atomic_load_acq_32(&nm_rxq->fl_cidx);
u_int fl_credits = fl_cidx & 7;
u_int ndesc = 0; /* desc processed since last cidx update */
u_int nframes = 0; /* frames processed since last netmap wakeup */
while ((d->rsp.u.type_gen & F_RSPD_GEN) == nm_rxq->iq_gen) {
@ -953,10 +959,6 @@ t4_nm_intr(void *arg)
switch (G_RSPD_TYPE(d->rsp.u.type_gen)) {
case X_RSPD_TYPE_FLBUF:
if (black_hole != 2) {
/* No buffer packing so new buf every time */
MPASS(lq & F_RSPD_NEWBUF);
}
/* fall through */
@ -975,9 +977,13 @@ t4_nm_intr(void *arg)
ring->slot[fl_cidx].len = G_RSPD_LEN(lq) -
sc->params.sge.fl_pktshift;
ring->slot[fl_cidx].flags = 0;
fl_cidx += (lq & F_RSPD_NEWBUF) ? 1 : 0;
fl_credits += (lq & F_RSPD_NEWBUF) ? 1 : 0;
if (__predict_false(fl_cidx == nm_rxq->fl_sidx))
nframes++;
if (!(lq & F_RSPD_NEWBUF)) {
MPASS(black_hole == 2);
break;
}
fl_credits++;
if (__predict_false(++fl_cidx == nm_rxq->fl_sidx))
fl_cidx = 0;
break;
default:
@ -1003,8 +1009,13 @@ t4_nm_intr(void *arg)
nm_rxq->iq_gen ^= F_RSPD_GEN;
}
if (__predict_false(++n == rx_ndesc)) {
if (__predict_false(++nframes == rx_nframes) && !black_hole) {
atomic_store_rel_32(&nm_rxq->fl_cidx, fl_cidx);
netmap_rx_irq(ifp, nm_rxq->nid, &work);
nframes = 0;
}
if (__predict_false(++ndesc == rx_ndesc)) {
if (black_hole && fl_credits >= 8) {
fl_credits /= 8;
IDXINCR(nm_rxq->fl_pidx, fl_credits * 8,
@ -1012,14 +1023,12 @@ t4_nm_intr(void *arg)
t4_write_reg(sc, sc->sge_kdoorbell_reg,
nm_rxq->fl_db_val | V_PIDX(fl_credits));
fl_credits = fl_cidx & 7;
} else if (!black_hole) {
netmap_rx_irq(ifp, nm_rxq->nid, &work);
MPASS(work != 0);
}
t4_write_reg(sc, sc->sge_gts_reg,
V_CIDXINC(n) | V_INGRESSQID(nm_rxq->iq_cntxt_id) |
V_CIDXINC(ndesc) |
V_INGRESSQID(nm_rxq->iq_cntxt_id) |
V_SEINTARM(V_QINTR_TIMER_IDX(X_TIMERREG_UPDATE_CIDX)));
n = 0;
ndesc = 0;
}
}
@ -1029,10 +1038,10 @@ t4_nm_intr(void *arg)
IDXINCR(nm_rxq->fl_pidx, fl_credits * 8, nm_rxq->fl_sidx);
t4_write_reg(sc, sc->sge_kdoorbell_reg,
nm_rxq->fl_db_val | V_PIDX(fl_credits));
} else
} else if (nframes > 0)
netmap_rx_irq(ifp, nm_rxq->nid, &work);
t4_write_reg(sc, sc->sge_gts_reg, V_CIDXINC(n) |
t4_write_reg(sc, sc->sge_gts_reg, V_CIDXINC(ndesc) |
V_INGRESSQID((u32)nm_rxq->iq_cntxt_id) |
V_SEINTARM(V_QINTR_TIMER_IDX(holdoff_tmr_idx)));
}