* [PATCH net-next v3 1/6] enetc: Refine buffer descriptor ring sizes
2020-07-21 7:55 [PATCH net-next v3 0/6] Add adaptive interrupt coalescing Claudiu Manoil
@ 2020-07-21 7:55 ` Claudiu Manoil
2020-07-21 7:55 ` [PATCH net-next v3 2/6] enetc: Factor out the traffic start/stop procedures Claudiu Manoil
` (6 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Claudiu Manoil @ 2020-07-21 7:55 UTC (permalink / raw)
To: David S . Miller; +Cc: Jakub Kicinski, netdev
It's time to differentiate between Rx and Tx ring sizes.
Not only Tx rings are processed differently than Rx rings,
but their default number also differs - i.e. up to 8 Tx rings
per device (8 traffic classes) vs. 2 Rx rings (one per CPU).
So let's set Tx rings sizes to half the size of the Rx rings
for now, to be conservative.
The default ring sizes were decreased as well (to the next
lower power of 2), to reduce the memory footprint, buffering
etc., since the measurements I've made so far show that the
rings are very unlikely to get full.
This change also anticipates the introduction of the
dynamic interrupt moderation (dim) algorithm which operates
on maximum packet thresholds of 256 packets for Rx and 128
packets for Tx.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
---
v2: none
v3: none
drivers/net/ethernet/freescale/enetc/enetc.c | 4 ++--
drivers/net/ethernet/freescale/enetc/enetc.h | 5 +++--
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index 3f32b85ba2cf..d91e52618681 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -1064,8 +1064,8 @@ void enetc_init_si_rings_params(struct enetc_ndev_priv *priv)
struct enetc_si *si = priv->si;
int cpus = num_online_cpus();
- priv->tx_bd_count = ENETC_BDR_DEFAULT_SIZE;
- priv->rx_bd_count = ENETC_BDR_DEFAULT_SIZE;
+ priv->tx_bd_count = ENETC_TX_RING_DEFAULT_SIZE;
+ priv->rx_bd_count = ENETC_RX_RING_DEFAULT_SIZE;
/* Enable all available TX rings in order to configure as many
* priorities as possible, when needed.
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index b705464f6882..0dd8ee179753 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -44,8 +44,9 @@ struct enetc_ring_stats {
unsigned int rx_alloc_errs;
};
-#define ENETC_BDR_DEFAULT_SIZE 1024
-#define ENETC_DEFAULT_TX_WORK 256
+#define ENETC_RX_RING_DEFAULT_SIZE 512
+#define ENETC_TX_RING_DEFAULT_SIZE 256
+#define ENETC_DEFAULT_TX_WORK (ENETC_TX_RING_DEFAULT_SIZE / 2)
struct enetc_bdr {
struct device *dev; /* for DMA mapping */
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH net-next v3 2/6] enetc: Factor out the traffic start/stop procedures
2020-07-21 7:55 [PATCH net-next v3 0/6] Add adaptive interrupt coalescing Claudiu Manoil
2020-07-21 7:55 ` [PATCH net-next v3 1/6] enetc: Refine buffer descriptor ring sizes Claudiu Manoil
@ 2020-07-21 7:55 ` Claudiu Manoil
2020-07-21 7:55 ` [PATCH net-next v3 3/6] enetc: Fix interrupt coalescing register naming Claudiu Manoil
` (5 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Claudiu Manoil @ 2020-07-21 7:55 UTC (permalink / raw)
To: David S . Miller; +Cc: Jakub Kicinski, netdev
A reliable traffic pause (and reconfiguration) procedure
is needed to be able to safely make h/w configuration
changes during run-time, like changing the mode in which the
interrupts are operating (i.e. with or without coalescing),
as opposed to making on-the-fly register updates that
may be subject to h/w or s/w concurrency issues.
To this end, the code responsible of the run-time device
configurations that basically starts resp. stops the traffic
flow through the device has been extracted from the
the enetc_open/_close procedures, to the separate standalone
enetc_start/_stop procedures. Traffic stop should be as
graceful as possible, it lets the executing napi threads to
to finish while the interrupts stay disabled. But since
the napi thread will try to re-enable interrupts by clearing
the device's unmask register, the enable_irq/ disable_irq
API has been used to avoid this potential concurrency issue
and make the traffic pause procedure more reliable.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
---
v2: none
v3: none
drivers/net/ethernet/freescale/enetc/enetc.c | 74 +++++++++++++-------
1 file changed, 49 insertions(+), 25 deletions(-)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index d91e52618681..51a1c97aedac 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -1264,6 +1264,7 @@ static int enetc_setup_irqs(struct enetc_ndev_priv *priv)
dev_err(priv->dev, "request_irq() failed!\n");
goto irq_err;
}
+ disable_irq(irq);
v->tbier_base = hw->reg + ENETC_BDR(TX, 0, ENETC_TBIER);
v->rbier = hw->reg + ENETC_BDR(RX, i, ENETC_RBIER);
@@ -1306,7 +1307,7 @@ static void enetc_free_irqs(struct enetc_ndev_priv *priv)
}
}
-static void enetc_enable_interrupts(struct enetc_ndev_priv *priv)
+static void enetc_setup_interrupts(struct enetc_ndev_priv *priv)
{
int i;
@@ -1322,7 +1323,7 @@ static void enetc_enable_interrupts(struct enetc_ndev_priv *priv)
}
}
-static void enetc_disable_interrupts(struct enetc_ndev_priv *priv)
+static void enetc_clear_interrupts(struct enetc_ndev_priv *priv)
{
int i;
@@ -1369,10 +1370,33 @@ static int enetc_phy_connect(struct net_device *ndev)
return 0;
}
+static void enetc_start(struct net_device *ndev)
+{
+ struct enetc_ndev_priv *priv = netdev_priv(ndev);
+ int i;
+
+ enetc_setup_interrupts(priv);
+
+ for (i = 0; i < priv->bdr_int_num; i++) {
+ int irq = pci_irq_vector(priv->si->pdev,
+ ENETC_BDR_INT_BASE_IDX + i);
+
+ napi_enable(&priv->int_vector[i]->napi);
+ enable_irq(irq);
+ }
+
+ if (ndev->phydev)
+ phy_start(ndev->phydev);
+ else
+ netif_carrier_on(ndev);
+
+ netif_tx_start_all_queues(ndev);
+}
+
int enetc_open(struct net_device *ndev)
{
struct enetc_ndev_priv *priv = netdev_priv(ndev);
- int i, err;
+ int err;
err = enetc_setup_irqs(priv);
if (err)
@@ -1390,8 +1414,6 @@ int enetc_open(struct net_device *ndev)
if (err)
goto err_alloc_rx;
- enetc_setup_bdrs(priv);
-
err = netif_set_real_num_tx_queues(ndev, priv->num_tx_rings);
if (err)
goto err_set_queues;
@@ -1400,17 +1422,8 @@ int enetc_open(struct net_device *ndev)
if (err)
goto err_set_queues;
- for (i = 0; i < priv->bdr_int_num; i++)
- napi_enable(&priv->int_vector[i]->napi);
-
- enetc_enable_interrupts(priv);
-
- if (ndev->phydev)
- phy_start(ndev->phydev);
- else
- netif_carrier_on(ndev);
-
- netif_tx_start_all_queues(ndev);
+ enetc_setup_bdrs(priv);
+ enetc_start(ndev);
return 0;
@@ -1427,28 +1440,39 @@ int enetc_open(struct net_device *ndev)
return err;
}
-int enetc_close(struct net_device *ndev)
+static void enetc_stop(struct net_device *ndev)
{
struct enetc_ndev_priv *priv = netdev_priv(ndev);
int i;
netif_tx_stop_all_queues(ndev);
- if (ndev->phydev) {
- phy_stop(ndev->phydev);
- phy_disconnect(ndev->phydev);
- } else {
- netif_carrier_off(ndev);
- }
-
for (i = 0; i < priv->bdr_int_num; i++) {
+ int irq = pci_irq_vector(priv->si->pdev,
+ ENETC_BDR_INT_BASE_IDX + i);
+
+ disable_irq(irq);
napi_synchronize(&priv->int_vector[i]->napi);
napi_disable(&priv->int_vector[i]->napi);
}
- enetc_disable_interrupts(priv);
+ if (ndev->phydev)
+ phy_stop(ndev->phydev);
+ else
+ netif_carrier_off(ndev);
+
+ enetc_clear_interrupts(priv);
+}
+
+int enetc_close(struct net_device *ndev)
+{
+ struct enetc_ndev_priv *priv = netdev_priv(ndev);
+
+ enetc_stop(ndev);
enetc_clear_bdrs(priv);
+ if (ndev->phydev)
+ phy_disconnect(ndev->phydev);
enetc_free_rxtx_rings(priv);
enetc_free_rx_resources(priv);
enetc_free_tx_resources(priv);
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH net-next v3 3/6] enetc: Fix interrupt coalescing register naming
2020-07-21 7:55 [PATCH net-next v3 0/6] Add adaptive interrupt coalescing Claudiu Manoil
2020-07-21 7:55 ` [PATCH net-next v3 1/6] enetc: Refine buffer descriptor ring sizes Claudiu Manoil
2020-07-21 7:55 ` [PATCH net-next v3 2/6] enetc: Factor out the traffic start/stop procedures Claudiu Manoil
@ 2020-07-21 7:55 ` Claudiu Manoil
2020-07-21 7:55 ` [PATCH net-next v3 4/6] enetc: Drop redundant ____cacheline_aligned_in_smp Claudiu Manoil
` (4 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Claudiu Manoil @ 2020-07-21 7:55 UTC (permalink / raw)
To: David S . Miller; +Cc: Jakub Kicinski, netdev
Interrupt coalescing registers naming in the current revision
of the Ref Man (RM) is ICR, deprecating the ICIR name used
in earlier (draft) versions of the RM.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
---
v2: none
v3: none
drivers/net/ethernet/freescale/enetc/enetc.c | 4 ++--
drivers/net/ethernet/freescale/enetc/enetc_ethtool.c | 2 +-
drivers/net/ethernet/freescale/enetc/enetc_hw.h | 8 ++++----
3 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index 51a1c97aedac..be594c7af538 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -1140,7 +1140,7 @@ static void enetc_setup_txbdr(struct enetc_hw *hw, struct enetc_bdr *tx_ring)
tx_ring->next_to_clean = enetc_txbdr_rd(hw, idx, ENETC_TBCIR);
/* enable Tx ints by setting pkt thr to 1 */
- enetc_txbdr_wr(hw, idx, ENETC_TBICIR0, ENETC_TBICIR0_ICEN | 0x1);
+ enetc_txbdr_wr(hw, idx, ENETC_TBICR0, ENETC_TBICR0_ICEN | 0x1);
tbmr = ENETC_TBMR_EN;
if (tx_ring->ndev->features & NETIF_F_HW_VLAN_CTAG_TX)
@@ -1174,7 +1174,7 @@ static void enetc_setup_rxbdr(struct enetc_hw *hw, struct enetc_bdr *rx_ring)
enetc_rxbdr_wr(hw, idx, ENETC_RBPIR, 0);
/* enable Rx ints by setting pkt thr to 1 */
- enetc_rxbdr_wr(hw, idx, ENETC_RBICIR0, ENETC_RBICIR0_ICEN | 0x1);
+ enetc_rxbdr_wr(hw, idx, ENETC_RBICR0, ENETC_RBICR0_ICEN | 0x1);
rbmr = ENETC_RBMR_EN;
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
index 34bd1f3fb415..8aeaa3de0012 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
@@ -19,7 +19,7 @@ static const u32 enetc_txbdr_regs[] = {
static const u32 enetc_rxbdr_regs[] = {
ENETC_RBMR, ENETC_RBSR, ENETC_RBBSR, ENETC_RBCIR, ENETC_RBBAR0,
- ENETC_RBBAR1, ENETC_RBPIR, ENETC_RBLENR, ENETC_RBICIR0, ENETC_RBIER
+ ENETC_RBBAR1, ENETC_RBPIR, ENETC_RBLENR, ENETC_RBICR0, ENETC_RBIER
};
static const u32 enetc_port_regs[] = {
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index 135bf46354ea..d70ee3722844 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -121,8 +121,8 @@ enum enetc_bdr_type {TX, RX};
#define ENETC_RBIER 0xa0
#define ENETC_RBIER_RXTIE BIT(0)
#define ENETC_RBIDR 0xa4
-#define ENETC_RBICIR0 0xa8
-#define ENETC_RBICIR0_ICEN BIT(31)
+#define ENETC_RBICR0 0xa8
+#define ENETC_RBICR0_ICEN BIT(31)
/* TX BDR reg offsets */
#define ENETC_TBMR 0
@@ -141,8 +141,8 @@ enum enetc_bdr_type {TX, RX};
#define ENETC_TBIER 0xa0
#define ENETC_TBIER_TXTIE BIT(0)
#define ENETC_TBIDR 0xa4
-#define ENETC_TBICIR0 0xa8
-#define ENETC_TBICIR0_ICEN BIT(31)
+#define ENETC_TBICR0 0xa8
+#define ENETC_TBICR0_ICEN BIT(31)
#define ENETC_RTBLENR_LEN(n) ((n) & ~0x7)
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH net-next v3 4/6] enetc: Drop redundant ____cacheline_aligned_in_smp
2020-07-21 7:55 [PATCH net-next v3 0/6] Add adaptive interrupt coalescing Claudiu Manoil
` (2 preceding siblings ...)
2020-07-21 7:55 ` [PATCH net-next v3 3/6] enetc: Fix interrupt coalescing register naming Claudiu Manoil
@ 2020-07-21 7:55 ` Claudiu Manoil
2020-07-21 7:55 ` [PATCH net-next v3 5/6] enetc: Add interrupt coalescing support Claudiu Manoil
` (3 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Claudiu Manoil @ 2020-07-21 7:55 UTC (permalink / raw)
To: David S . Miller; +Cc: Jakub Kicinski, netdev
'struct enetc_bdr' is already '____cacheline_aligned_in_smp'.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
---
v2: none
v3: none
drivers/net/ethernet/freescale/enetc/enetc.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 0dd8ee179753..81e9072e10d4 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -195,7 +195,7 @@ struct enetc_int_vector {
struct napi_struct napi;
char name[ENETC_INT_NAME_MAX];
- struct enetc_bdr rx_ring ____cacheline_aligned_in_smp;
+ struct enetc_bdr rx_ring;
struct enetc_bdr tx_ring[];
};
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH net-next v3 5/6] enetc: Add interrupt coalescing support
2020-07-21 7:55 [PATCH net-next v3 0/6] Add adaptive interrupt coalescing Claudiu Manoil
` (3 preceding siblings ...)
2020-07-21 7:55 ` [PATCH net-next v3 4/6] enetc: Drop redundant ____cacheline_aligned_in_smp Claudiu Manoil
@ 2020-07-21 7:55 ` Claudiu Manoil
2020-07-21 7:55 ` [PATCH net-next v3 6/6] enetc: Add adaptive interrupt coalescing Claudiu Manoil
` (2 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Claudiu Manoil @ 2020-07-21 7:55 UTC (permalink / raw)
To: David S . Miller; +Cc: Jakub Kicinski, netdev
Enable programming of the interrupt coalescing registers
and allow manual configuration of the coalescing time
thresholds via ethtool. Packet thresholds have been fixed
to predetermined values as there's no point in making them
run-time configurable, also anticipating the dynamic interrupt
moderation (DIM) algorithm which uses fixed packet thresholds
as well. If the interface is up when the operation mode of
traffic interrupt events is changed by the user (i.e. switching
from default per-packet interrupts to coalesced interrupts),
the traffic needs to be paused in the process.
This patch also prepares the ground for introducing DIM on Rx.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
---
v2: removed tx_ictt from the "fast path", as Tx updates
remain static (dropped Tx DIM idea)
v3: return -EOPNOTSUPP instead of error message
drivers/net/ethernet/freescale/enetc/enetc.c | 32 ++++++--
drivers/net/ethernet/freescale/enetc/enetc.h | 18 +++++
.../ethernet/freescale/enetc/enetc_ethtool.c | 73 ++++++++++++++++++-
.../net/ethernet/freescale/enetc/enetc_hw.h | 19 ++++-
4 files changed, 132 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index be594c7af538..f4593c044043 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -265,6 +265,7 @@ static irqreturn_t enetc_msix(int irq, void *data)
/* disable interrupts */
enetc_wr_reg(v->rbier, 0);
+ enetc_wr_reg(v->ricr1, v->rx_ictt);
for_each_set_bit(i, &v->tx_rings_map, ENETC_MAX_NUM_TXQS)
enetc_wr_reg(v->tbier_base + ENETC_BDR_OFF(i), 0);
@@ -1268,6 +1269,7 @@ static int enetc_setup_irqs(struct enetc_ndev_priv *priv)
v->tbier_base = hw->reg + ENETC_BDR(TX, 0, ENETC_TBIER);
v->rbier = hw->reg + ENETC_BDR(RX, i, ENETC_RBIER);
+ v->ricr1 = hw->reg + ENETC_BDR(RX, i, ENETC_RBICR1);
enetc_wr(hw, ENETC_SIMSIRRV(i), entry);
@@ -1309,17 +1311,35 @@ static void enetc_free_irqs(struct enetc_ndev_priv *priv)
static void enetc_setup_interrupts(struct enetc_ndev_priv *priv)
{
+ struct enetc_hw *hw = &priv->si->hw;
+ u32 icpt, ictt;
int i;
/* enable Tx & Rx event indication */
+ if (priv->ic_mode & ENETC_IC_RX_MANUAL) {
+ icpt = ENETC_RBICR0_SET_ICPT(ENETC_RXIC_PKTTHR);
+ /* init to non-0 minimum, will be adjusted later */
+ ictt = 0x1;
+ } else {
+ icpt = 0x1; /* enable Rx ints by setting pkt thr to 1 */
+ ictt = 0;
+ }
+
for (i = 0; i < priv->num_rx_rings; i++) {
- enetc_rxbdr_wr(&priv->si->hw, i,
- ENETC_RBIER, ENETC_RBIER_RXTIE);
+ enetc_rxbdr_wr(hw, i, ENETC_RBICR1, ictt);
+ enetc_rxbdr_wr(hw, i, ENETC_RBICR0, ENETC_RBICR0_ICEN | icpt);
+ enetc_rxbdr_wr(hw, i, ENETC_RBIER, ENETC_RBIER_RXTIE);
}
+ if (priv->ic_mode & ENETC_IC_TX_MANUAL)
+ icpt = ENETC_TBICR0_SET_ICPT(ENETC_TXIC_PKTTHR);
+ else
+ icpt = 0x1; /* enable Tx ints by setting pkt thr to 1 */
+
for (i = 0; i < priv->num_tx_rings; i++) {
- enetc_txbdr_wr(&priv->si->hw, i,
- ENETC_TBIER, ENETC_TBIER_TXTIE);
+ enetc_txbdr_wr(hw, i, ENETC_TBICR1, priv->tx_ictt);
+ enetc_txbdr_wr(hw, i, ENETC_TBICR0, ENETC_TBICR0_ICEN | icpt);
+ enetc_txbdr_wr(hw, i, ENETC_TBIER, ENETC_TBIER_TXTIE);
}
}
@@ -1370,7 +1390,7 @@ static int enetc_phy_connect(struct net_device *ndev)
return 0;
}
-static void enetc_start(struct net_device *ndev)
+void enetc_start(struct net_device *ndev)
{
struct enetc_ndev_priv *priv = netdev_priv(ndev);
int i;
@@ -1440,7 +1460,7 @@ int enetc_open(struct net_device *ndev)
return err;
}
-static void enetc_stop(struct net_device *ndev)
+void enetc_stop(struct net_device *ndev)
{
struct enetc_ndev_priv *priv = netdev_priv(ndev);
int i;
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 81e9072e10d4..4e3af7f07892 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -190,8 +190,10 @@ static inline bool enetc_si_is_pf(struct enetc_si *si)
struct enetc_int_vector {
void __iomem *rbier;
void __iomem *tbier_base;
+ void __iomem *ricr1;
unsigned long tx_rings_map;
int count_tx_rings;
+ u32 rx_ictt;
struct napi_struct napi;
char name[ENETC_INT_NAME_MAX];
@@ -221,6 +223,18 @@ enum enetc_active_offloads {
ENETC_F_QCI = BIT(3),
};
+/* interrupt coalescing modes */
+enum enetc_ic_mode {
+ /* one interrupt per frame */
+ ENETC_IC_NONE = 0,
+ /* activated when int coalescing time is set to a non-0 value */
+ ENETC_IC_RX_MANUAL = BIT(0),
+ ENETC_IC_TX_MANUAL = BIT(1),
+};
+
+#define ENETC_RXIC_PKTTHR min_t(u32, 256, ENETC_RX_RING_DEFAULT_SIZE / 2)
+#define ENETC_TXIC_PKTTHR min_t(u32, 128, ENETC_TX_RING_DEFAULT_SIZE / 2)
+
struct enetc_ndev_priv {
struct net_device *ndev;
struct device *dev; /* dma-mapping device */
@@ -245,6 +259,8 @@ struct enetc_ndev_priv {
struct device_node *phy_node;
phy_interface_t if_mode;
+ int ic_mode;
+ u32 tx_ictt;
};
/* Messaging */
@@ -274,6 +290,8 @@ void enetc_free_si_resources(struct enetc_ndev_priv *priv);
int enetc_open(struct net_device *ndev);
int enetc_close(struct net_device *ndev);
+void enetc_start(struct net_device *ndev);
+void enetc_stop(struct net_device *ndev);
netdev_tx_t enetc_xmit(struct sk_buff *skb, struct net_device *ndev);
struct net_device_stats *enetc_get_stats(struct net_device *ndev);
int enetc_set_features(struct net_device *ndev,
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
index 8aeaa3de0012..521f3b4cd250 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
@@ -14,12 +14,14 @@ static const u32 enetc_si_regs[] = {
static const u32 enetc_txbdr_regs[] = {
ENETC_TBMR, ENETC_TBSR, ENETC_TBBAR0, ENETC_TBBAR1,
- ENETC_TBPIR, ENETC_TBCIR, ENETC_TBLENR, ENETC_TBIER
+ ENETC_TBPIR, ENETC_TBCIR, ENETC_TBLENR, ENETC_TBIER, ENETC_TBICR0,
+ ENETC_TBICR1
};
static const u32 enetc_rxbdr_regs[] = {
ENETC_RBMR, ENETC_RBSR, ENETC_RBBSR, ENETC_RBCIR, ENETC_RBBAR0,
- ENETC_RBBAR1, ENETC_RBPIR, ENETC_RBLENR, ENETC_RBICR0, ENETC_RBIER
+ ENETC_RBBAR1, ENETC_RBPIR, ENETC_RBLENR, ENETC_RBIER, ENETC_RBICR0,
+ ENETC_RBICR1
};
static const u32 enetc_port_regs[] = {
@@ -561,6 +563,65 @@ static void enetc_get_ringparam(struct net_device *ndev,
}
}
+static int enetc_get_coalesce(struct net_device *ndev,
+ struct ethtool_coalesce *ic)
+{
+ struct enetc_ndev_priv *priv = netdev_priv(ndev);
+ struct enetc_int_vector *v = priv->int_vector[0];
+
+ ic->tx_coalesce_usecs = enetc_cycles_to_usecs(priv->tx_ictt);
+ ic->rx_coalesce_usecs = enetc_cycles_to_usecs(v->rx_ictt);
+
+ ic->tx_max_coalesced_frames = ENETC_TXIC_PKTTHR;
+ ic->rx_max_coalesced_frames = ENETC_RXIC_PKTTHR;
+
+ return 0;
+}
+
+static int enetc_set_coalesce(struct net_device *ndev,
+ struct ethtool_coalesce *ic)
+{
+ struct enetc_ndev_priv *priv = netdev_priv(ndev);
+ u32 rx_ictt, tx_ictt;
+ int i, ic_mode;
+ bool changed;
+
+ tx_ictt = enetc_usecs_to_cycles(ic->tx_coalesce_usecs);
+ rx_ictt = enetc_usecs_to_cycles(ic->rx_coalesce_usecs);
+
+ if (ic->rx_max_coalesced_frames != ENETC_RXIC_PKTTHR)
+ return -EOPNOTSUPP;
+
+ if (ic->tx_max_coalesced_frames != ENETC_TXIC_PKTTHR)
+ return -EOPNOTSUPP;
+
+ ic_mode = ENETC_IC_NONE;
+ ic_mode |= tx_ictt ? ENETC_IC_TX_MANUAL : 0;
+ ic_mode |= rx_ictt ? ENETC_IC_RX_MANUAL : 0;
+
+ /* commit the settings */
+ changed = (ic_mode != priv->ic_mode);
+
+ priv->ic_mode = ic_mode;
+ priv->tx_ictt = tx_ictt;
+
+ for (i = 0; i < priv->bdr_int_num; i++) {
+ struct enetc_int_vector *v = priv->int_vector[i];
+
+ v->rx_ictt = rx_ictt;
+ }
+
+ if (netif_running(ndev) && changed) {
+ /* reconfigure the operation mode of h/w interrupts,
+ * traffic needs to be paused in the process
+ */
+ enetc_stop(ndev);
+ enetc_start(ndev);
+ }
+
+ return 0;
+}
+
static int enetc_get_ts_info(struct net_device *ndev,
struct ethtool_ts_info *info)
{
@@ -617,6 +678,8 @@ static int enetc_set_wol(struct net_device *dev,
}
static const struct ethtool_ops enetc_pf_ethtool_ops = {
+ .supported_coalesce_params = ETHTOOL_COALESCE_USECS |
+ ETHTOOL_COALESCE_MAX_FRAMES,
.get_regs_len = enetc_get_reglen,
.get_regs = enetc_get_regs,
.get_sset_count = enetc_get_sset_count,
@@ -629,6 +692,8 @@ static const struct ethtool_ops enetc_pf_ethtool_ops = {
.get_rxfh = enetc_get_rxfh,
.set_rxfh = enetc_set_rxfh,
.get_ringparam = enetc_get_ringparam,
+ .get_coalesce = enetc_get_coalesce,
+ .set_coalesce = enetc_set_coalesce,
.get_link_ksettings = phy_ethtool_get_link_ksettings,
.set_link_ksettings = phy_ethtool_set_link_ksettings,
.get_link = ethtool_op_get_link,
@@ -638,6 +703,8 @@ static const struct ethtool_ops enetc_pf_ethtool_ops = {
};
static const struct ethtool_ops enetc_vf_ethtool_ops = {
+ .supported_coalesce_params = ETHTOOL_COALESCE_USECS |
+ ETHTOOL_COALESCE_MAX_FRAMES,
.get_regs_len = enetc_get_reglen,
.get_regs = enetc_get_regs,
.get_sset_count = enetc_get_sset_count,
@@ -649,6 +716,8 @@ static const struct ethtool_ops enetc_vf_ethtool_ops = {
.get_rxfh = enetc_get_rxfh,
.set_rxfh = enetc_set_rxfh,
.get_ringparam = enetc_get_ringparam,
+ .get_coalesce = enetc_get_coalesce,
+ .set_coalesce = enetc_set_coalesce,
.get_link = ethtool_op_get_link,
.get_ts_info = enetc_get_ts_info,
};
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index d70ee3722844..17cf7c94fdb5 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -122,7 +122,10 @@ enum enetc_bdr_type {TX, RX};
#define ENETC_RBIER_RXTIE BIT(0)
#define ENETC_RBIDR 0xa4
#define ENETC_RBICR0 0xa8
-#define ENETC_RBICR0_ICEN BIT(31)
+#define ENETC_RBICR0_ICEN BIT(31)
+#define ENETC_RBICR0_ICPT_MASK 0x1ff
+#define ENETC_RBICR0_SET_ICPT(n) ((n) & ENETC_RBICR0_ICPT_MASK)
+#define ENETC_RBICR1 0xac
/* TX BDR reg offsets */
#define ENETC_TBMR 0
@@ -142,7 +145,10 @@ enum enetc_bdr_type {TX, RX};
#define ENETC_TBIER_TXTIE BIT(0)
#define ENETC_TBIDR 0xa4
#define ENETC_TBICR0 0xa8
-#define ENETC_TBICR0_ICEN BIT(31)
+#define ENETC_TBICR0_ICEN BIT(31)
+#define ENETC_TBICR0_ICPT_MASK 0xf
+#define ENETC_TBICR0_SET_ICPT(n) ((ilog2(n) + 1) & ENETC_TBICR0_ICPT_MASK)
+#define ENETC_TBICR1 0xac
#define ENETC_RTBLENR_LEN(n) ((n) & ~0x7)
@@ -787,6 +793,15 @@ struct enetc_cbd {
};
#define ENETC_CLK 400000000ULL
+static inline u32 enetc_cycles_to_usecs(u32 cycles)
+{
+ return (u32)div_u64(cycles * 1000000ULL, ENETC_CLK);
+}
+
+static inline u32 enetc_usecs_to_cycles(u32 usecs)
+{
+ return (u32)div_u64(usecs * ENETC_CLK, 1000000ULL);
+}
/* port time gating control register */
#define ENETC_QBV_PTGCR_OFFSET 0x11a00
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH net-next v3 6/6] enetc: Add adaptive interrupt coalescing
2020-07-21 7:55 [PATCH net-next v3 0/6] Add adaptive interrupt coalescing Claudiu Manoil
` (4 preceding siblings ...)
2020-07-21 7:55 ` [PATCH net-next v3 5/6] enetc: Add interrupt coalescing support Claudiu Manoil
@ 2020-07-21 7:55 ` Claudiu Manoil
2020-07-21 19:23 ` [PATCH net-next v3 0/6] " Jakub Kicinski
2020-07-21 22:38 ` David Miller
7 siblings, 0 replies; 9+ messages in thread
From: Claudiu Manoil @ 2020-07-21 7:55 UTC (permalink / raw)
To: David S . Miller; +Cc: Jakub Kicinski, netdev
Use the generic dynamic interrupt moderation (dim)
framework to implement adaptive interrupt coalescing
on Rx. With the per-packet interrupt scheme, a high
interrupt rate has been noted for moderate traffic flows
leading to high CPU utilization. The 'dim' scheme
implemented by the current patch addresses this issue
improving CPU utilization while using minimal coalescing
time thresholds in order to preserve a good latency.
On the Tx side use an optimal time threshold value by
default. This value has been optimized for Tx TCP
streams at a rate of around 85kpps on a 1G link,
at which rate half of the Tx ring size (128) gets filled
in 1500 usecs. Scaling this down to 2.5G links yields
the current value of 600 usecs, which is conservative
and gives good enough results for 1G links too (see
next).
Below are some measurement results for before and after
this patch (and related dependencies) basically, for a
2 ARM Cortex-A72 @1.3Ghz CPUs system (32 KB L1 data cache),
using 60secs log netperf TCP stream tests @ 1Gbit link
(maximum throughput):
1) 1 Rx TCP flow, both Rx and Tx processed by the same NAPI
thread on the same CPU:
CPU utilization int rate (ints/sec)
Before: 50%-60% (over 50%) 92k
After: 13%-22% 3.5k-12k
Comment: Major CPU utilization improvement for a single flow
Rx TCP flow (i.e. netperf -t TCP_MAERTS) on a single
CPU. Usually settles under 16% for longer tests.
2) 4 Rx TCP flows + 4 Tx TCP flows (+ pings to check the latency):
Total CPU utilization Total int rate (ints/sec)
Before: ~80% (spikes to 90%) ~100k
After: 60% (more steady) ~4k
Comment: Important improvement for this load test, while the
ping test outcome does not show any notable
difference compared to before.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
---
v2: Replaced Tx DIM with static optimal value.
v3: simplified the code by dropping the 'OPTIMAL' flag
drivers/net/ethernet/freescale/enetc/Kconfig | 2 +
drivers/net/ethernet/freescale/enetc/enetc.c | 48 ++++++++++++++++++-
drivers/net/ethernet/freescale/enetc/enetc.h | 11 ++++-
.../ethernet/freescale/enetc/enetc_ethtool.c | 19 ++++++--
4 files changed, 73 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/freescale/enetc/Kconfig b/drivers/net/ethernet/freescale/enetc/Kconfig
index 2b43848e1363..37b804f8bd76 100644
--- a/drivers/net/ethernet/freescale/enetc/Kconfig
+++ b/drivers/net/ethernet/freescale/enetc/Kconfig
@@ -4,6 +4,7 @@ config FSL_ENETC
depends on PCI && PCI_MSI
select FSL_ENETC_MDIO
select PHYLIB
+ select DIMLIB
help
This driver supports NXP ENETC gigabit ethernet controller PCIe
physical function (PF) devices, managing ENETC Ports at a privileged
@@ -15,6 +16,7 @@ config FSL_ENETC_VF
tristate "ENETC VF driver"
depends on PCI && PCI_MSI
select PHYLIB
+ select DIMLIB
help
This driver supports NXP ENETC gigabit ethernet controller PCIe
virtual function (VF) devices enabled by the ENETC PF driver.
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index f4593c044043..f50353cbb4db 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -279,6 +279,34 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget);
static int enetc_clean_rx_ring(struct enetc_bdr *rx_ring,
struct napi_struct *napi, int work_limit);
+static void enetc_rx_dim_work(struct work_struct *w)
+{
+ struct dim *dim = container_of(w, struct dim, work);
+ struct dim_cq_moder moder =
+ net_dim_get_rx_moderation(dim->mode, dim->profile_ix);
+ struct enetc_int_vector *v =
+ container_of(dim, struct enetc_int_vector, rx_dim);
+
+ v->rx_ictt = enetc_usecs_to_cycles(moder.usec);
+ dim->state = DIM_START_MEASURE;
+}
+
+static void enetc_rx_net_dim(struct enetc_int_vector *v)
+{
+ struct dim_sample dim_sample;
+
+ v->comp_cnt++;
+
+ if (!v->rx_napi_work)
+ return;
+
+ dim_update_sample(v->comp_cnt,
+ v->rx_ring.stats.packets,
+ v->rx_ring.stats.bytes,
+ &dim_sample);
+ net_dim(&v->rx_dim, dim_sample);
+}
+
static int enetc_poll(struct napi_struct *napi, int budget)
{
struct enetc_int_vector
@@ -294,12 +322,19 @@ static int enetc_poll(struct napi_struct *napi, int budget)
work_done = enetc_clean_rx_ring(&v->rx_ring, napi, budget);
if (work_done == budget)
complete = false;
+ if (work_done)
+ v->rx_napi_work = true;
if (!complete)
return budget;
napi_complete_done(napi, work_done);
+ if (likely(v->rx_dim_en))
+ enetc_rx_net_dim(v);
+
+ v->rx_napi_work = false;
+
/* enable interrupts */
enetc_wr_reg(v->rbier, ENETC_RBIER_RXTIE);
@@ -1075,6 +1110,8 @@ void enetc_init_si_rings_params(struct enetc_ndev_priv *priv)
priv->num_rx_rings = min_t(int, cpus, si->num_rx_rings);
priv->num_tx_rings = si->num_tx_rings;
priv->bdr_int_num = cpus;
+ priv->ic_mode = ENETC_IC_RX_ADAPTIVE | ENETC_IC_TX_MANUAL;
+ priv->tx_ictt = ENETC_TXIC_TIMETHR;
/* SI specific */
si->cbd_ring.bd_count = ENETC_CBDR_DEFAULT_SIZE;
@@ -1316,7 +1353,8 @@ static void enetc_setup_interrupts(struct enetc_ndev_priv *priv)
int i;
/* enable Tx & Rx event indication */
- if (priv->ic_mode & ENETC_IC_RX_MANUAL) {
+ if (priv->ic_mode &
+ (ENETC_IC_RX_MANUAL | ENETC_IC_RX_ADAPTIVE)) {
icpt = ENETC_RBICR0_SET_ICPT(ENETC_RXIC_PKTTHR);
/* init to non-0 minimum, will be adjusted later */
ictt = 0x1;
@@ -1786,6 +1824,12 @@ int enetc_alloc_msix(struct enetc_ndev_priv *priv)
priv->int_vector[i] = v;
+ /* init defaults for adaptive IC */
+ if (priv->ic_mode & ENETC_IC_RX_ADAPTIVE) {
+ v->rx_ictt = 0x1;
+ v->rx_dim_en = true;
+ }
+ INIT_WORK(&v->rx_dim.work, enetc_rx_dim_work);
netif_napi_add(priv->ndev, &v->napi, enetc_poll,
NAPI_POLL_WEIGHT);
v->count_tx_rings = v_tx_rings;
@@ -1821,6 +1865,7 @@ int enetc_alloc_msix(struct enetc_ndev_priv *priv)
fail:
while (i--) {
netif_napi_del(&priv->int_vector[i]->napi);
+ cancel_work_sync(&priv->int_vector[i]->rx_dim.work);
kfree(priv->int_vector[i]);
}
@@ -1837,6 +1882,7 @@ void enetc_free_msix(struct enetc_ndev_priv *priv)
struct enetc_int_vector *v = priv->int_vector[i];
netif_napi_del(&v->napi);
+ cancel_work_sync(&v->rx_dim.work);
}
for (i = 0; i < priv->num_rx_rings; i++)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 4e3af7f07892..d309803cfeb6 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -10,6 +10,7 @@
#include <linux/ethtool.h>
#include <linux/if_vlan.h>
#include <linux/phy.h>
+#include <linux/dim.h>
#include "enetc_hw.h"
@@ -194,12 +195,15 @@ struct enetc_int_vector {
unsigned long tx_rings_map;
int count_tx_rings;
u32 rx_ictt;
- struct napi_struct napi;
+ u16 comp_cnt;
+ bool rx_dim_en, rx_napi_work;
+ struct napi_struct napi ____cacheline_aligned_in_smp;
+ struct dim rx_dim ____cacheline_aligned_in_smp;
char name[ENETC_INT_NAME_MAX];
struct enetc_bdr rx_ring;
struct enetc_bdr tx_ring[];
-};
+} ____cacheline_aligned_in_smp;
struct enetc_cls_rule {
struct ethtool_rx_flow_spec fs;
@@ -230,10 +234,13 @@ enum enetc_ic_mode {
/* activated when int coalescing time is set to a non-0 value */
ENETC_IC_RX_MANUAL = BIT(0),
ENETC_IC_TX_MANUAL = BIT(1),
+ /* use dynamic interrupt moderation */
+ ENETC_IC_RX_ADAPTIVE = BIT(2),
};
#define ENETC_RXIC_PKTTHR min_t(u32, 256, ENETC_RX_RING_DEFAULT_SIZE / 2)
#define ENETC_TXIC_PKTTHR min_t(u32, 128, ENETC_TX_RING_DEFAULT_SIZE / 2)
+#define ENETC_TXIC_TIMETHR enetc_usecs_to_cycles(600)
struct enetc_ndev_priv {
struct net_device *ndev;
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
index 521f3b4cd250..1dab83fbca77 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
@@ -575,6 +575,8 @@ static int enetc_get_coalesce(struct net_device *ndev,
ic->tx_max_coalesced_frames = ENETC_TXIC_PKTTHR;
ic->rx_max_coalesced_frames = ENETC_RXIC_PKTTHR;
+ ic->use_adaptive_rx_coalesce = priv->ic_mode & ENETC_IC_RX_ADAPTIVE;
+
return 0;
}
@@ -596,11 +598,17 @@ static int enetc_set_coalesce(struct net_device *ndev,
return -EOPNOTSUPP;
ic_mode = ENETC_IC_NONE;
+ if (ic->use_adaptive_rx_coalesce) {
+ ic_mode |= ENETC_IC_RX_ADAPTIVE;
+ rx_ictt = 0x1;
+ } else {
+ ic_mode |= rx_ictt ? ENETC_IC_RX_MANUAL : 0;
+ }
+
ic_mode |= tx_ictt ? ENETC_IC_TX_MANUAL : 0;
- ic_mode |= rx_ictt ? ENETC_IC_RX_MANUAL : 0;
/* commit the settings */
- changed = (ic_mode != priv->ic_mode);
+ changed = (ic_mode != priv->ic_mode) || (priv->tx_ictt != tx_ictt);
priv->ic_mode = ic_mode;
priv->tx_ictt = tx_ictt;
@@ -609,6 +617,7 @@ static int enetc_set_coalesce(struct net_device *ndev,
struct enetc_int_vector *v = priv->int_vector[i];
v->rx_ictt = rx_ictt;
+ v->rx_dim_en = !!(ic_mode & ENETC_IC_RX_ADAPTIVE);
}
if (netif_running(ndev) && changed) {
@@ -679,7 +688,8 @@ static int enetc_set_wol(struct net_device *dev,
static const struct ethtool_ops enetc_pf_ethtool_ops = {
.supported_coalesce_params = ETHTOOL_COALESCE_USECS |
- ETHTOOL_COALESCE_MAX_FRAMES,
+ ETHTOOL_COALESCE_MAX_FRAMES |
+ ETHTOOL_COALESCE_USE_ADAPTIVE_RX,
.get_regs_len = enetc_get_reglen,
.get_regs = enetc_get_regs,
.get_sset_count = enetc_get_sset_count,
@@ -704,7 +714,8 @@ static const struct ethtool_ops enetc_pf_ethtool_ops = {
static const struct ethtool_ops enetc_vf_ethtool_ops = {
.supported_coalesce_params = ETHTOOL_COALESCE_USECS |
- ETHTOOL_COALESCE_MAX_FRAMES,
+ ETHTOOL_COALESCE_MAX_FRAMES |
+ ETHTOOL_COALESCE_USE_ADAPTIVE_RX,
.get_regs_len = enetc_get_reglen,
.get_regs = enetc_get_regs,
.get_sset_count = enetc_get_sset_count,
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH net-next v3 0/6] Add adaptive interrupt coalescing
2020-07-21 7:55 [PATCH net-next v3 0/6] Add adaptive interrupt coalescing Claudiu Manoil
` (5 preceding siblings ...)
2020-07-21 7:55 ` [PATCH net-next v3 6/6] enetc: Add adaptive interrupt coalescing Claudiu Manoil
@ 2020-07-21 19:23 ` Jakub Kicinski
2020-07-21 22:38 ` David Miller
7 siblings, 0 replies; 9+ messages in thread
From: Jakub Kicinski @ 2020-07-21 19:23 UTC (permalink / raw)
To: Claudiu Manoil; +Cc: David S . Miller, netdev
On Tue, 21 Jul 2020 10:55:16 +0300 Claudiu Manoil wrote:
> Apart from some related cleanup patches, this set
> introduces in a straightforward way the support needed
> to enable and configure interrupt coalescing for ENETC.
>
> Patch 5 introduces the support needed for configuring the
> interrupt coalescing parameters and for switching between
> moderated (int. coalescing) and per-packet interrupt modes.
> When interrupt coalescing is enabled the Rx/Tx time
> thresholds are configurable, packet thresholds are fixed.
> To make this work reliably, patch 5 uses the traffic
> pause procedure introduced in patch 2.
>
> Patch 6 adds DIM (Dynamic Interrupt Moderation) to implement
> adaptive coalescing based on time thresholds, for the Rx 'channel'.
> On the Tx side a default optimal value is used instead, optimized for
> TCP traffic over 1G and 2.5G links. This default 'optimal' value can
> be overridden anytime via 'ethtool -C tx-usecs'.
>
> netperf -t TCP_MAERTS measurements show a significant CPU load
> reduction correlated w/ reduced interrupt rates. For the
> measurement results refer to the comments in patch 6.
>
> v2: Replaced Tx DIM with predefined optimal value, giving
> better results. This was also suggested by Jakub (cc).
> Switched order of patches 4 and 5, for better grouping.
Acked-by: Jakub Kicinski <kuba@kernel.org>
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH net-next v3 0/6] Add adaptive interrupt coalescing
2020-07-21 7:55 [PATCH net-next v3 0/6] Add adaptive interrupt coalescing Claudiu Manoil
` (6 preceding siblings ...)
2020-07-21 19:23 ` [PATCH net-next v3 0/6] " Jakub Kicinski
@ 2020-07-21 22:38 ` David Miller
7 siblings, 0 replies; 9+ messages in thread
From: David Miller @ 2020-07-21 22:38 UTC (permalink / raw)
To: claudiu.manoil; +Cc: kuba, netdev
From: Claudiu Manoil <claudiu.manoil@nxp.com>
Date: Tue, 21 Jul 2020 10:55:16 +0300
> Apart from some related cleanup patches, this set
> introduces in a straightforward way the support needed
> to enable and configure interrupt coalescing for ENETC.
>
> Patch 5 introduces the support needed for configuring the
> interrupt coalescing parameters and for switching between
> moderated (int. coalescing) and per-packet interrupt modes.
> When interrupt coalescing is enabled the Rx/Tx time
> thresholds are configurable, packet thresholds are fixed.
> To make this work reliably, patch 5 uses the traffic
> pause procedure introduced in patch 2.
>
> Patch 6 adds DIM (Dynamic Interrupt Moderation) to implement
> adaptive coalescing based on time thresholds, for the Rx 'channel'.
> On the Tx side a default optimal value is used instead, optimized for
> TCP traffic over 1G and 2.5G links. This default 'optimal' value can
> be overridden anytime via 'ethtool -C tx-usecs'.
>
> netperf -t TCP_MAERTS measurements show a significant CPU load
> reduction correlated w/ reduced interrupt rates. For the
> measurement results refer to the comments in patch 6.
>
> v2: Replaced Tx DIM with predefined optimal value, giving
> better results. This was also suggested by Jakub (cc).
> Switched order of patches 4 and 5, for better grouping.
>
> v3: minor cleanup/improvements
Series applied, thank you.
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