pktgen: better scheduler friendliness
Previous update did not resched in inner loop causing watchdogs.
Rewrite inner loop to:
* account for delays better with less clock calls
* more accurate timing of delay:
- only delay if packet was successfully sent
- if delay is 100ns and it takes 10ns to build packet then
account for that
* use wait_event_interruptible_timeout rather than open coding it.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stephen Hemminger
David S. Miller
parent
6b80d6a6b4
commit
ef87979c27
|
|
@ -2104,7 +2104,7 @@ static void pktgen_setup_inject(struct pktgen_dev *pkt_dev)
|
|||
|
||||
static void spin(struct pktgen_dev *pkt_dev, ktime_t spin_until)
|
||||
{
|
||||
ktime_t start;
|
||||
ktime_t start_time, end_time;
|
||||
s32 remaining;
|
||||
struct hrtimer_sleeper t;
|
||||
|
||||
|
|
@ -2115,7 +2115,7 @@ static void spin(struct pktgen_dev *pkt_dev, ktime_t spin_until)
|
|||
if (remaining <= 0)
|
||||
return;
|
||||
|
||||
start = ktime_now();
|
||||
start_time = ktime_now();
|
||||
if (remaining < 100)
|
||||
udelay(remaining); /* really small just spin */
|
||||
else {
|
||||
|
|
@ -2134,7 +2134,10 @@ static void spin(struct pktgen_dev *pkt_dev, ktime_t spin_until)
|
|||
} while (t.task && pkt_dev->running && !signal_pending(current));
|
||||
__set_current_state(TASK_RUNNING);
|
||||
}
|
||||
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(ktime_now(), start));
|
||||
end_time = ktime_now();
|
||||
|
||||
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(end_time, start_time));
|
||||
pkt_dev->next_tx = ktime_add_ns(end_time, pkt_dev->delay);
|
||||
}
|
||||
|
||||
static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev)
|
||||
|
|
@ -3364,18 +3367,28 @@ static void pktgen_rem_thread(struct pktgen_thread *t)
|
|||
mutex_unlock(&pktgen_thread_lock);
|
||||
}
|
||||
|
||||
static void idle(struct pktgen_dev *pkt_dev)
|
||||
static void pktgen_resched(struct pktgen_dev *pkt_dev)
|
||||
{
|
||||
ktime_t idle_start = ktime_now();
|
||||
|
||||
if (need_resched())
|
||||
schedule();
|
||||
else
|
||||
cpu_relax();
|
||||
|
||||
schedule();
|
||||
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(ktime_now(), idle_start));
|
||||
}
|
||||
|
||||
static void pktgen_wait_for_skb(struct pktgen_dev *pkt_dev)
|
||||
{
|
||||
ktime_t idle_start = ktime_now();
|
||||
|
||||
while (atomic_read(&(pkt_dev->skb->users)) != 1) {
|
||||
if (signal_pending(current))
|
||||
break;
|
||||
|
||||
if (need_resched())
|
||||
pktgen_resched(pkt_dev);
|
||||
else
|
||||
cpu_relax();
|
||||
}
|
||||
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(ktime_now(), idle_start));
|
||||
}
|
||||
|
||||
static void pktgen_xmit(struct pktgen_dev *pkt_dev)
|
||||
{
|
||||
|
|
@ -3386,36 +3399,21 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
|
|||
u16 queue_map;
|
||||
int ret;
|
||||
|
||||
if (pkt_dev->delay) {
|
||||
spin(pkt_dev, pkt_dev->next_tx);
|
||||
|
||||
/* This is max DELAY, this has special meaning of
|
||||
* "never transmit"
|
||||
*/
|
||||
if (pkt_dev->delay == ULLONG_MAX) {
|
||||
pkt_dev->next_tx = ktime_add_ns(ktime_now(), ULONG_MAX);
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
if (!pkt_dev->skb) {
|
||||
set_cur_queue_map(pkt_dev);
|
||||
queue_map = pkt_dev->cur_queue_map;
|
||||
} else {
|
||||
queue_map = skb_get_queue_mapping(pkt_dev->skb);
|
||||
}
|
||||
|
||||
txq = netdev_get_tx_queue(odev, queue_map);
|
||||
/* Did we saturate the queue already? */
|
||||
if (netif_tx_queue_stopped(txq) || netif_tx_queue_frozen(txq)) {
|
||||
/* If device is down, then all queues are permnantly frozen */
|
||||
if (netif_running(odev))
|
||||
idle(pkt_dev);
|
||||
else
|
||||
pktgen_stop_device(pkt_dev);
|
||||
/* If device is offline, then don't send */
|
||||
if (unlikely(!netif_running(odev) || !netif_carrier_ok(odev))) {
|
||||
pktgen_stop_device(pkt_dev);
|
||||
return;
|
||||
}
|
||||
|
||||
/* This is max DELAY, this has special meaning of
|
||||
* "never transmit"
|
||||
*/
|
||||
if (unlikely(pkt_dev->delay == ULLONG_MAX)) {
|
||||
pkt_dev->next_tx = ktime_add_ns(ktime_now(), ULONG_MAX);
|
||||
return;
|
||||
}
|
||||
|
||||
/* If no skb or clone count exhausted then get new one */
|
||||
if (!pkt_dev->skb || (pkt_dev->last_ok &&
|
||||
++pkt_dev->clone_count >= pkt_dev->clone_skb)) {
|
||||
/* build a new pkt */
|
||||
|
|
@ -3434,54 +3432,45 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
|
|||
pkt_dev->clone_count = 0; /* reset counter */
|
||||
}
|
||||
|
||||
/* fill_packet() might have changed the queue */
|
||||
if (pkt_dev->delay && pkt_dev->last_ok)
|
||||
spin(pkt_dev, pkt_dev->next_tx);
|
||||
|
||||
queue_map = skb_get_queue_mapping(pkt_dev->skb);
|
||||
txq = netdev_get_tx_queue(odev, queue_map);
|
||||
|
||||
__netif_tx_lock_bh(txq);
|
||||
atomic_inc(&(pkt_dev->skb->users));
|
||||
|
||||
if (unlikely(netif_tx_queue_stopped(txq) || netif_tx_queue_frozen(txq)))
|
||||
pkt_dev->last_ok = 0;
|
||||
else {
|
||||
atomic_inc(&(pkt_dev->skb->users));
|
||||
|
||||
retry_now:
|
||||
ret = NETDEV_TX_BUSY;
|
||||
else
|
||||
ret = (*xmit)(pkt_dev->skb, odev);
|
||||
switch (ret) {
|
||||
case NETDEV_TX_OK:
|
||||
txq_trans_update(txq);
|
||||
pkt_dev->last_ok = 1;
|
||||
pkt_dev->sofar++;
|
||||
pkt_dev->seq_num++;
|
||||
pkt_dev->tx_bytes += pkt_dev->cur_pkt_size;
|
||||
break;
|
||||
case NETDEV_TX_LOCKED:
|
||||
cpu_relax();
|
||||
goto retry_now;
|
||||
default: /* Drivers are not supposed to return other values! */
|
||||
if (net_ratelimit())
|
||||
pr_info("pktgen: %s xmit error: %d\n",
|
||||
odev->name, ret);
|
||||
pkt_dev->errors++;
|
||||
/* fallthru */
|
||||
case NETDEV_TX_BUSY:
|
||||
/* Retry it next time */
|
||||
atomic_dec(&(pkt_dev->skb->users));
|
||||
pkt_dev->last_ok = 0;
|
||||
}
|
||||
|
||||
if (pkt_dev->delay)
|
||||
pkt_dev->next_tx = ktime_add_ns(ktime_now(),
|
||||
pkt_dev->delay);
|
||||
switch (ret) {
|
||||
case NETDEV_TX_OK:
|
||||
txq_trans_update(txq);
|
||||
pkt_dev->last_ok = 1;
|
||||
pkt_dev->sofar++;
|
||||
pkt_dev->seq_num++;
|
||||
pkt_dev->tx_bytes += pkt_dev->cur_pkt_size;
|
||||
break;
|
||||
default: /* Drivers are not supposed to return other values! */
|
||||
if (net_ratelimit())
|
||||
pr_info("pktgen: %s xmit error: %d\n",
|
||||
odev->name, ret);
|
||||
pkt_dev->errors++;
|
||||
/* fallthru */
|
||||
case NETDEV_TX_LOCKED:
|
||||
case NETDEV_TX_BUSY:
|
||||
/* Retry it next time */
|
||||
atomic_dec(&(pkt_dev->skb->users));
|
||||
pkt_dev->last_ok = 0;
|
||||
}
|
||||
__netif_tx_unlock_bh(txq);
|
||||
|
||||
/* If pkt_dev->count is zero, then run forever */
|
||||
if ((pkt_dev->count != 0) && (pkt_dev->sofar >= pkt_dev->count)) {
|
||||
while (atomic_read(&(pkt_dev->skb->users)) != 1) {
|
||||
if (signal_pending(current))
|
||||
break;
|
||||
idle(pkt_dev);
|
||||
}
|
||||
pktgen_wait_for_skb(pkt_dev);
|
||||
|
||||
/* Done with this */
|
||||
pktgen_stop_device(pkt_dev);
|
||||
|
|
@ -3514,20 +3503,24 @@ static int pktgen_thread_worker(void *arg)
|
|||
while (!kthread_should_stop()) {
|
||||
pkt_dev = next_to_run(t);
|
||||
|
||||
if (!pkt_dev &&
|
||||
(t->control & (T_STOP | T_RUN | T_REMDEVALL | T_REMDEV))
|
||||
== 0) {
|
||||
prepare_to_wait(&(t->queue), &wait,
|
||||
TASK_INTERRUPTIBLE);
|
||||
schedule_timeout(HZ / 10);
|
||||
finish_wait(&(t->queue), &wait);
|
||||
if (unlikely(!pkt_dev && t->control == 0)) {
|
||||
wait_event_interruptible_timeout(t->queue,
|
||||
t->control != 0,
|
||||
HZ/10);
|
||||
continue;
|
||||
}
|
||||
|
||||
__set_current_state(TASK_RUNNING);
|
||||
|
||||
if (pkt_dev)
|
||||
if (likely(pkt_dev)) {
|
||||
pktgen_xmit(pkt_dev);
|
||||
|
||||
if (need_resched())
|
||||
pktgen_resched(pkt_dev);
|
||||
else
|
||||
cpu_relax();
|
||||
}
|
||||
|
||||
if (t->control & T_STOP) {
|
||||
pktgen_stop(t);
|
||||
t->control &= ~(T_STOP);
|
||||
|
|
|
|||
Loading…
Reference in New Issue