This driver uses a normal timer for TX coalescing, which means that the
with the default tx-usecs of 1000 microseconds the cleanups actually
happen 10 ms or more later with HZ=100. This leads to very low
througput with TCP when bridged to a slow link such as a 4G modem. Fix
this by using an hrtimer instead.
On my ARM platform with HZ=100 and the default TX coalescing settings
(tx-frames 25 tx-usecs 1000), with "tc qdisc add dev eth0 root netem
delay 60ms 40ms rate 50Mbit" run on the server, netperf's TCP_STREAM
improves from ~5.5 Mbps to ~100 Mbps.
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20201120150208.6838-1-vincent.whitchurch@axis.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
#define DRV_MODULE_VERSION "Jan_2016"
#include <linux/clk.h>
#define DRV_MODULE_VERSION "Jan_2016"
#include <linux/clk.h>
+#include <linux/hrtimer.h>
#include <linux/if_vlan.h>
#include <linux/stmmac.h>
#include <linux/phylink.h>
#include <linux/if_vlan.h>
#include <linux/stmmac.h>
#include <linux/phylink.h>
struct stmmac_tx_queue {
u32 tx_count_frames;
int tbs;
struct stmmac_tx_queue {
u32 tx_count_frames;
int tbs;
- struct timer_list txtimer;
+ struct hrtimer txtimer;
u32 queue_index;
struct stmmac_priv *priv_data;
struct dma_extended_desc *dma_etx ____cacheline_aligned_in_smp;
u32 queue_index;
struct stmmac_priv *priv_data;
struct dma_extended_desc *dma_etx ____cacheline_aligned_in_smp;
static void stmmac_exit_fs(struct net_device *dev);
#endif
static void stmmac_exit_fs(struct net_device *dev);
#endif
-#define STMMAC_COAL_TIMER(x) (jiffies + usecs_to_jiffies(x))
+#define STMMAC_COAL_TIMER(x) (ns_to_ktime((x) * NSEC_PER_USEC))
/**
* stmmac_verify_args - verify the driver parameters.
/**
* stmmac_verify_args - verify the driver parameters.
/* We still have pending packets, let's call for a new scheduling */
if (tx_q->dirty_tx != tx_q->cur_tx)
/* We still have pending packets, let's call for a new scheduling */
if (tx_q->dirty_tx != tx_q->cur_tx)
- mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(priv->tx_coal_timer));
+ hrtimer_start(&tx_q->txtimer, STMMAC_COAL_TIMER(priv->tx_coal_timer),
+ HRTIMER_MODE_REL);
__netif_tx_unlock_bh(netdev_get_tx_queue(priv->dev, queue));
__netif_tx_unlock_bh(netdev_get_tx_queue(priv->dev, queue));
{
struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
{
struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
- mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(priv->tx_coal_timer));
+ hrtimer_start(&tx_q->txtimer, STMMAC_COAL_TIMER(priv->tx_coal_timer),
+ HRTIMER_MODE_REL);
* Description:
* This is the timer handler to directly invoke the stmmac_tx_clean.
*/
* Description:
* This is the timer handler to directly invoke the stmmac_tx_clean.
*/
-static void stmmac_tx_timer(struct timer_list *t)
+static enum hrtimer_restart stmmac_tx_timer(struct hrtimer *t)
- struct stmmac_tx_queue *tx_q = from_timer(tx_q, t, txtimer);
+ struct stmmac_tx_queue *tx_q = container_of(t, struct stmmac_tx_queue, txtimer);
struct stmmac_priv *priv = tx_q->priv_data;
struct stmmac_channel *ch;
struct stmmac_priv *priv = tx_q->priv_data;
struct stmmac_channel *ch;
spin_unlock_irqrestore(&ch->lock, flags);
__napi_schedule(&ch->tx_napi);
}
spin_unlock_irqrestore(&ch->lock, flags);
__napi_schedule(&ch->tx_napi);
}
+
+ return HRTIMER_NORESTART;
for (chan = 0; chan < tx_channel_count; chan++) {
struct stmmac_tx_queue *tx_q = &priv->tx_queue[chan];
for (chan = 0; chan < tx_channel_count; chan++) {
struct stmmac_tx_queue *tx_q = &priv->tx_queue[chan];
- timer_setup(&tx_q->txtimer, stmmac_tx_timer, 0);
+ hrtimer_init(&tx_q->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ tx_q->txtimer.function = stmmac_tx_timer;
phylink_stop(priv->phylink);
for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
phylink_stop(priv->phylink);
for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
- del_timer_sync(&priv->tx_queue[chan].txtimer);
+ hrtimer_cancel(&priv->tx_queue[chan].txtimer);
stmmac_hw_teardown(dev);
init_error:
stmmac_hw_teardown(dev);
init_error:
stmmac_disable_all_queues(priv);
for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
stmmac_disable_all_queues(priv);
for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
- del_timer_sync(&priv->tx_queue[chan].txtimer);
+ hrtimer_cancel(&priv->tx_queue[chan].txtimer);
/* Free the IRQ lines */
free_irq(dev->irq, dev);
/* Free the IRQ lines */
free_irq(dev->irq, dev);
stmmac_disable_all_queues(priv);
for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
stmmac_disable_all_queues(priv);
for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
- del_timer_sync(&priv->tx_queue[chan].txtimer);
+ hrtimer_cancel(&priv->tx_queue[chan].txtimer);
/* Stop TX/RX DMA */
stmmac_stop_all_dma(priv);
/* Stop TX/RX DMA */
stmmac_stop_all_dma(priv);