diff options
| author |   Hariprasad Shenai <hariprasad@chelsio.com> | 2015-02-04 15:32:52 +0530 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2015-02-04 23:55:58 -0800 |
| commit | 3a336cb17183b29827fdffaffb5e62f8912f5ca1 (patch) | |
| tree | 0ca09203cd1f8ace3496ad697e85679c658f0861 /drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | |
| parent | Revert "bridge: Let bridge not age 'externally' learnt FDB entries, they are removed when 'external' entity notifies the aging" (diff) | |
| download | linux-dev-3a336cb17183b29827fdffaffb5e62f8912f5ca1.tar.xz linux-dev-3a336cb17183b29827fdffaffb5e62f8912f5ca1.zip | |
cxgb4: Add low latency socket busy_poll support
cxgb_busy_poll, corresponding to ndo_busy_poll, gets called by the socket
waiting for data.
With busy_poll enabled, improvement is seen in latency numbers as observed by
collecting netperf TCP_RR numbers.
Below are latency number, with and without busy-poll, in a switched environment
for a particular msg size:
netperf command: netperf -4 -H <ip> -l 30 -t TCP_RR -- -r1,1
Latency without busy-poll: ~16.25 us
Latency with busy-poll : ~08.79 us
Based on original work by Kumar Sanghvi <kumaras@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c')
| -rw-r--r-- | drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c index 5bf490a781aa..041742b5e0e8 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c @@ -923,8 +923,14 @@ static void quiesce_rx(struct adapter *adap) for (i = 0; i < ARRAY_SIZE(adap->sge.ingr_map); i++) { struct sge_rspq *q = adap->sge.ingr_map[i]; - if (q && q->handler) + if (q && q->handler) { napi_disable(&q->napi); + local_bh_disable(); + while (!cxgb_poll_lock_napi(q)) + mdelay(1); + local_bh_enable(); + } + } } @@ -940,8 +946,10 @@ static void enable_rx(struct adapter *adap) if (!q) continue; - if (q->handler) + if (q->handler) { + cxgb_busy_poll_init_lock(q); napi_enable(&q->napi); + } /* 0-increment GTS to start the timer and enable interrupts */ t4_write_reg(adap, MYPF_REG(SGE_PF_GTS_A), SEINTARM_V(q->intr_params) | @@ -4563,6 +4571,10 @@ static const struct net_device_ops cxgb4_netdev_ops = { #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = cxgb_netpoll, #endif +#ifdef CONFIG_NET_RX_BUSY_POLL + .ndo_busy_poll = cxgb_busy_poll, +#endif + }; void t4_fatal_err(struct adapter *adap) |