diff options
| author |   Antoine Tenart <antoine.tenart@free-electrons.com> | 2017-10-30 11:23:31 +0100 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-11-01 12:28:33 +0900 |
| commit | 1d17db08c056c1f7f4abbff6aff8711b7c3a3b7f (patch) | |
| tree | 0e6904dc0aefda40c7cac7639c4761bed6447cd5 /drivers | |
| parent | net: mvpp2: initialize the RSS tables (diff) | |
| download | linux-dev-1d17db08c056c1f7f4abbff6aff8711b7c3a3b7f.tar.xz linux-dev-1d17db08c056c1f7f4abbff6aff8711b7c3a3b7f.zip | |
net: mvpp2: limit TSO segments and use stop/wake thresholds
Too many TSO descriptors can be required for the default queue size,
when using small MSS values for example. Prevent this by adding a
maximum number of allowed TSO segments (300). In addition set a stop and
a wake thresholds to stop the queue when there's no room for a 1 "worst
case scenario skb". Wake up the queue when the number of descriptors is
low enough.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/marvell/mvpp2.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/net/ethernet/marvell/mvpp2.c b/drivers/net/ethernet/marvell/mvpp2.c index 54d80df1c1ac..340b4d682951 100644 --- a/drivers/net/ethernet/marvell/mvpp2.c +++ b/drivers/net/ethernet/marvell/mvpp2.c @@ -493,6 +493,13 @@ /* Maximum number of TXQs used by single port */ #define MVPP2_MAX_TXQ 8 +/* MVPP2_MAX_TSO_SEGS is the maximum number of fragments to allow in the GSO + * skb. As we need a maxium of two descriptors per fragments (1 header, 1 data), + * multiply this value by two to count the maximum number of skb descs needed. + */ +#define MVPP2_MAX_TSO_SEGS 300 +#define MVPP2_MAX_SKB_DESCS (MVPP2_MAX_TSO_SEGS * 2 + MAX_SKB_FRAGS) + /* Dfault number of RXQs in use */ #define MVPP2_DEFAULT_RXQ 4 @@ -1045,6 +1052,9 @@ struct mvpp2_txq_pcpu { */ int count; + int wake_threshold; + int stop_threshold; + /* Number of Tx DMA descriptors reserved for each CPU */ int reserved_num; @@ -5393,7 +5403,7 @@ static void mvpp2_txq_done(struct mvpp2_port *port, struct mvpp2_tx_queue *txq, txq_pcpu->count -= tx_done; if (netif_tx_queue_stopped(nq)) - if (txq_pcpu->size - txq_pcpu->count >= MAX_SKB_FRAGS + 1) + if (txq_pcpu->count <= txq_pcpu->wake_threshold) netif_tx_wake_queue(nq); } @@ -5636,6 +5646,9 @@ static int mvpp2_txq_init(struct mvpp2_port *port, txq_pcpu->txq_put_index = 0; txq_pcpu->txq_get_index = 0; + txq_pcpu->stop_threshold = txq->size - MVPP2_MAX_SKB_DESCS; + txq_pcpu->wake_threshold = txq_pcpu->stop_threshold / 2; + txq_pcpu->tso_headers = dma_alloc_coherent(port->dev->dev.parent, txq_pcpu->size * TSO_HEADER_SIZE, @@ -6508,7 +6521,7 @@ out: wmb(); mvpp2_aggr_txq_pend_desc_add(port, frags); - if (txq_pcpu->size - txq_pcpu->count < MAX_SKB_FRAGS + 1) + if (txq_pcpu->count >= txq_pcpu->stop_threshold) netif_tx_stop_queue(nq); u64_stats_update_begin(&stats->syncp); @@ -7732,6 +7745,7 @@ static int mvpp2_port_probe(struct platform_device *pdev, dev->features = features | NETIF_F_RXCSUM; dev->hw_features |= features | NETIF_F_RXCSUM | NETIF_F_GRO; dev->vlan_features |= features; + dev->gso_max_segs = MVPP2_MAX_TSO_SEGS; /* MTU range: 68 - 9676 */ dev->min_mtu = ETH_MIN_MTU; |