Commit 2bc481cf authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller

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: default avatarStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fd29cf72
...@@ -485,6 +485,7 @@ void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id, ...@@ -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); debug_object_init_on_stack(timer, &hrtimer_debug_descr);
__hrtimer_init(timer, clock_id, mode); __hrtimer_init(timer, clock_id, mode);
} }
EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);
void destroy_hrtimer_on_stack(struct hrtimer *timer) void destroy_hrtimer_on_stack(struct hrtimer *timer)
{ {
...@@ -1477,6 +1478,7 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) ...@@ -1477,6 +1478,7 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
sl->timer.function = hrtimer_wakeup; sl->timer.function = hrtimer_wakeup;
sl->task = task; sl->task = task;
} }
EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode) static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
{ {
......
...@@ -131,6 +131,7 @@ ...@@ -131,6 +131,7 @@
#include <linux/ioport.h> #include <linux/ioport.h>
#include <linux/interrupt.h> #include <linux/interrupt.h>
#include <linux/capability.h> #include <linux/capability.h>
#include <linux/hrtimer.h>
#include <linux/freezer.h> #include <linux/freezer.h>
#include <linux/delay.h> #include <linux/delay.h>
#include <linux/timer.h> #include <linux/timer.h>
...@@ -2086,33 +2087,40 @@ static void pktgen_setup_inject(struct pktgen_dev *pkt_dev) ...@@ -2086,33 +2087,40 @@ static void pktgen_setup_inject(struct pktgen_dev *pkt_dev)
pkt_dev->nflows = 0; 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) static void spin(struct pktgen_dev *pkt_dev, ktime_t spin_until)
{ {
ktime_t start, now; ktime_t start;
s64 dt; 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);
remaining = ktime_to_us(hrtimer_expires_remaining(&t.timer));
if (remaining <= 0)
return;
while ((dt = delta_ns(spin_until, now)) > 0) { start = ktime_now();
/* TODO: optimize sleeping behavior */ if (remaining < 100)
if (dt > TICK_NSEC) udelay(remaining); /* really small just spin */
schedule_timeout_interruptible(1); else {
else if (dt > 100*NSEC_PER_USEC) { /* see do_nanosleep */
if (!pkt_dev->running) hrtimer_init_sleeper(&t, current);
return; do {
if (need_resched()) 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(); 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(ktime_now(), start));
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(now, start));
} }
static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev) static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev)
...@@ -3360,8 +3368,7 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) ...@@ -3360,8 +3368,7 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
int ret; int ret;
if (pkt_dev->delay) { 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 /* This is max DELAY, this has special meaning of
* "never transmit" * "never transmit"
......
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