pktgen: spin using hrtimer

This changes how the pktgen thread spins/waits between
packets if delay is configured. It uses a high res timer to
wait for time to arrive.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stephen Hemminger 2009-08-28 23:41:29 -07:00 committed by David S. Miller
parent fd29cf7262
commit 2bc481cf43
2 changed files with 30 additions and 21 deletions

View file

@ -485,6 +485,7 @@ void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id,
debug_object_init_on_stack(timer, &hrtimer_debug_descr);
__hrtimer_init(timer, clock_id, mode);
}
EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);
void destroy_hrtimer_on_stack(struct hrtimer *timer)
{
@ -1477,6 +1478,7 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
sl->timer.function = hrtimer_wakeup;
sl->task = task;
}
EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
{

View file

@ -131,6 +131,7 @@
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/capability.h>
#include <linux/hrtimer.h>
#include <linux/freezer.h>
#include <linux/delay.h>
#include <linux/timer.h>
@ -2086,33 +2087,40 @@ static void pktgen_setup_inject(struct pktgen_dev *pkt_dev)
pkt_dev->nflows = 0;
}
static inline s64 delta_ns(ktime_t a, ktime_t b)
{
return ktime_to_ns(ktime_sub(a, b));
}
static void spin(struct pktgen_dev *pkt_dev, ktime_t spin_until)
{
ktime_t start, now;
s64 dt;
ktime_t start;
s32 remaining;
struct hrtimer_sleeper t;
start = now = ktime_now();
hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
hrtimer_set_expires(&t.timer, spin_until);
while ((dt = delta_ns(spin_until, now)) > 0) {
/* TODO: optimize sleeping behavior */
if (dt > TICK_NSEC)
schedule_timeout_interruptible(1);
else if (dt > 100*NSEC_PER_USEC) {
if (!pkt_dev->running)
return;
if (need_resched())
remaining = ktime_to_us(hrtimer_expires_remaining(&t.timer));
if (remaining <= 0)
return;
start = ktime_now();
if (remaining < 100)
udelay(remaining); /* really small just spin */
else {
/* see do_nanosleep */
hrtimer_init_sleeper(&t, current);
do {
set_current_state(TASK_INTERRUPTIBLE);
hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS);
if (!hrtimer_active(&t.timer))
t.task = NULL;
if (likely(t.task))
schedule();
}
now = ktime_now();
hrtimer_cancel(&t.timer);
} while (t.task && pkt_dev->running && !signal_pending(current));
__set_current_state(TASK_RUNNING);
}
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(now, start));
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(ktime_now(), start));
}
static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev)
@ -3360,8 +3368,7 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
int ret;
if (pkt_dev->delay) {
if (ktime_lt(ktime_now(), pkt_dev->next_tx))
spin(pkt_dev, pkt_dev->next_tx);
spin(pkt_dev, pkt_dev->next_tx);
/* This is max DELAY, this has special meaning of
* "never transmit"