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pktgen: convert to use ktime_t
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The kernel ktime_t is a nice generic infrastructure for mananging
high resolution times, as is done in pktgen.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Stephen Hemminger authored and David S. Miller committed Aug 29, 2009
1 parent 5c9d191 commit fd29cf7
Showing 1 changed file with 84 additions and 100 deletions.
184 changes: 84 additions & 100 deletions net/core/pktgen.c
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Original file line number Diff line number Diff line change
Expand Up @@ -246,26 +246,26 @@ struct pktgen_dev {
int max_pkt_size; /* = ETH_ZLEN; */
int pkt_overhead; /* overhead for MPLS, VLANs, IPSEC etc */
int nfrags;
__u32 delay_us; /* Default delay */
__u32 delay_ns;
u64 delay; /* nano-seconds */

__u64 count; /* Default No packets to send */
__u64 sofar; /* How many pkts we've sent so far */
__u64 tx_bytes; /* How many bytes we've transmitted */
__u64 errors; /* Errors when trying to transmit, pkts will be re-sent */

/* runtime counters relating to clone_skb */
__u64 next_tx_us; /* timestamp of when to tx next */
__u32 next_tx_ns;

__u64 allocated_skbs;
__u32 clone_count;
int last_ok; /* Was last skb sent?
* Or a failed transmit of some sort? This will keep
* sequence numbers in order, for example.
*/
__u64 started_at; /* micro-seconds */
__u64 stopped_at; /* micro-seconds */
__u64 idle_acc; /* micro-seconds */
ktime_t next_tx;
ktime_t started_at;
ktime_t stopped_at;
u64 idle_acc; /* nano-seconds */

__u32 seq_num;

int clone_skb; /* Use multiple SKBs during packet gen. If this number
Expand Down Expand Up @@ -397,23 +397,20 @@ struct pktgen_thread {
#define REMOVE 1
#define FIND 0

/** Convert to micro-seconds */
static inline __u64 tv_to_us(const struct timeval *tv)
static inline ktime_t ktime_now(void)
{
__u64 us = tv->tv_usec;
us += (__u64) tv->tv_sec * (__u64) 1000000;
return us;
struct timespec ts;
ktime_get_ts(&ts);

return timespec_to_ktime(ts);
}

static __u64 getCurUs(void)
/* This works even if 32 bit because of careful byte order choice */
static inline int ktime_lt(const ktime_t cmp1, const ktime_t cmp2)
{
struct timeval tv;
do_gettimeofday(&tv);
return tv_to_us(&tv);
return cmp1.tv64 < cmp2.tv64;
}

/* old include end */

static const char version[] __initconst = VERSION;

static int pktgen_remove_device(struct pktgen_thread *t, struct pktgen_dev *i);
Expand Down Expand Up @@ -510,19 +507,17 @@ static const struct file_operations pktgen_fops = {
static int pktgen_if_show(struct seq_file *seq, void *v)
{
const struct pktgen_dev *pkt_dev = seq->private;
__u64 sa;
__u64 stopped;
__u64 now = getCurUs();
ktime_t stopped;
u64 idle;

seq_printf(seq,
"Params: count %llu min_pkt_size: %u max_pkt_size: %u\n",
(unsigned long long)pkt_dev->count, pkt_dev->min_pkt_size,
pkt_dev->max_pkt_size);

seq_printf(seq,
" frags: %d delay: %u clone_skb: %d ifname: %s\n",
pkt_dev->nfrags,
1000 * pkt_dev->delay_us + pkt_dev->delay_ns,
" frags: %d delay: %llu clone_skb: %d ifname: %s\n",
pkt_dev->nfrags, (unsigned long long) pkt_dev->delay,
pkt_dev->clone_skb, pkt_dev->odev->name);

seq_printf(seq, " flows: %u flowlen: %u\n", pkt_dev->cflows,
Expand Down Expand Up @@ -654,17 +649,21 @@ static int pktgen_if_show(struct seq_file *seq, void *v)

seq_puts(seq, "\n");

sa = pkt_dev->started_at;
stopped = pkt_dev->stopped_at;
if (pkt_dev->running)
stopped = now; /* not really stopped, more like last-running-at */
/* not really stopped, more like last-running-at */
stopped = pkt_dev->running ? ktime_now() : pkt_dev->stopped_at;
idle = pkt_dev->idle_acc;
do_div(idle, NSEC_PER_USEC);

seq_printf(seq,
"Current:\n pkts-sofar: %llu errors: %llu\n started: %lluus stopped: %lluus idle: %lluus\n",
"Current:\n pkts-sofar: %llu errors: %llu\n",
(unsigned long long)pkt_dev->sofar,
(unsigned long long)pkt_dev->errors, (unsigned long long)sa,
(unsigned long long)stopped,
(unsigned long long)pkt_dev->idle_acc);
(unsigned long long)pkt_dev->errors);

seq_printf(seq,
" started: %lluus stopped: %lluus idle: %lluus\n",
(unsigned long long) ktime_to_us(pkt_dev->started_at),
(unsigned long long) ktime_to_us(stopped),
(unsigned long long) idle);

seq_printf(seq,
" seq_num: %d cur_dst_mac_offset: %d cur_src_mac_offset: %d\n",
Expand Down Expand Up @@ -950,15 +949,13 @@ static ssize_t pktgen_if_write(struct file *file,
return len;
}
i += len;
if (value == 0x7FFFFFFF) {
pkt_dev->delay_us = 0x7FFFFFFF;
pkt_dev->delay_ns = 0;
} else {
pkt_dev->delay_us = value / 1000;
pkt_dev->delay_ns = value % 1000;
}
sprintf(pg_result, "OK: delay=%u",
1000 * pkt_dev->delay_us + pkt_dev->delay_ns);
if (value == 0x7FFFFFFF)
pkt_dev->delay = ULLONG_MAX;
else
pkt_dev->delay = (u64)value * NSEC_PER_USEC;

sprintf(pg_result, "OK: delay=%llu",
(unsigned long long) pkt_dev->delay);
return count;
}
if (!strcmp(name, "udp_src_min")) {
Expand Down Expand Up @@ -2089,27 +2086,33 @@ static void pktgen_setup_inject(struct pktgen_dev *pkt_dev)
pkt_dev->nflows = 0;
}

static void spin(struct pktgen_dev *pkt_dev, __u64 spin_until_us)
static inline s64 delta_ns(ktime_t a, ktime_t b)
{
__u64 start;
__u64 now;
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;

start = now = ktime_now();

start = now = getCurUs();
while (now < spin_until_us) {
while ((dt = delta_ns(spin_until, now)) > 0) {
/* TODO: optimize sleeping behavior */
if (spin_until_us - now > jiffies_to_usecs(1) + 1)
if (dt > TICK_NSEC)
schedule_timeout_interruptible(1);
else if (spin_until_us - now > 100) {
else if (dt > 100*NSEC_PER_USEC) {
if (!pkt_dev->running)
return;
if (need_resched())
schedule();
}

now = getCurUs();
now = ktime_now();
}

pkt_dev->idle_acc += now - start;
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(now, start));
}

static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev)
Expand Down Expand Up @@ -3070,9 +3073,9 @@ static void pktgen_run(struct pktgen_thread *t)
pktgen_clear_counters(pkt_dev);
pkt_dev->running = 1; /* Cranke yeself! */
pkt_dev->skb = NULL;
pkt_dev->started_at = getCurUs();
pkt_dev->next_tx_us = getCurUs(); /* Transmit immediately */
pkt_dev->next_tx_ns = 0;
pkt_dev->started_at =
pkt_dev->next_tx = ktime_now();

set_pkt_overhead(pkt_dev);

strcpy(pkt_dev->result, "Starting");
Expand Down Expand Up @@ -3188,28 +3191,21 @@ static void pktgen_reset_all_threads(void)

static void show_results(struct pktgen_dev *pkt_dev, int nr_frags)
{
__u64 total_us, bps, mbps, pps, idle;
__u64 bps, mbps, pps;
char *p = pkt_dev->result;

total_us = pkt_dev->stopped_at - pkt_dev->started_at;

idle = pkt_dev->idle_acc;

p += sprintf(p, "OK: %llu(c%llu+d%llu) usec, %llu (%dbyte,%dfrags)\n",
(unsigned long long)total_us,
(unsigned long long)(total_us - idle),
(unsigned long long)idle,
ktime_t elapsed = ktime_sub(pkt_dev->stopped_at,
pkt_dev->started_at);
ktime_t idle = ns_to_ktime(pkt_dev->idle_acc);

p += sprintf(p, "OK: %llu(c%llu+d%llu) nsec, %llu (%dbyte,%dfrags)\n",
(unsigned long long)ktime_to_us(elapsed),
(unsigned long long)ktime_to_us(ktime_sub(elapsed, idle)),
(unsigned long long)ktime_to_us(idle),
(unsigned long long)pkt_dev->sofar,
pkt_dev->cur_pkt_size, nr_frags);

pps = pkt_dev->sofar * USEC_PER_SEC;

while ((total_us >> 32) != 0) {
pps >>= 1;
total_us >>= 1;
}

do_div(pps, total_us);
pps = div64_u64(pkt_dev->sofar * NSEC_PER_SEC,
ktime_to_ns(elapsed));

bps = pps * 8 * pkt_dev->cur_pkt_size;

Expand All @@ -3235,7 +3231,7 @@ static int pktgen_stop_device(struct pktgen_dev *pkt_dev)

kfree_skb(pkt_dev->skb);
pkt_dev->skb = NULL;
pkt_dev->stopped_at = getCurUs();
pkt_dev->stopped_at = ktime_now();
pkt_dev->running = 0;

show_results(pkt_dev, nr_frags);
Expand All @@ -3254,7 +3250,7 @@ static struct pktgen_dev *next_to_run(struct pktgen_thread *t)
continue;
if (best == NULL)
best = pkt_dev;
else if (pkt_dev->next_tx_us < best->next_tx_us)
else if (ktime_lt(pkt_dev->next_tx, best->next_tx))
best = pkt_dev;
}
if_unlock(t);
Expand Down Expand Up @@ -3343,16 +3339,17 @@ static void pktgen_rem_thread(struct pktgen_thread *t)

static void idle(struct pktgen_dev *pkt_dev)
{
u64 idle_start = getCurUs();
ktime_t idle_start = ktime_now();

if (need_resched())
schedule();
else
cpu_relax();

pkt_dev->idle_acc += getCurUs() - idle_start;
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(ktime_now(), idle_start));
}


static void pktgen_xmit(struct pktgen_dev *pkt_dev)
{
struct net_device *odev = pkt_dev->odev;
Expand All @@ -3362,19 +3359,15 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
u16 queue_map;
int ret;

if (pkt_dev->delay_us || pkt_dev->delay_ns) {
u64 now;

now = getCurUs();
if (now < pkt_dev->next_tx_us)
spin(pkt_dev, pkt_dev->next_tx_us);
if (pkt_dev->delay) {
if (ktime_lt(ktime_now(), pkt_dev->next_tx))
spin(pkt_dev, pkt_dev->next_tx);

/* This is max DELAY, this has special meaning of
* "never transmit"
*/
if (pkt_dev->delay_us == 0x7FFFFFFF) {
pkt_dev->next_tx_us = getCurUs() + pkt_dev->delay_us;
pkt_dev->next_tx_ns = pkt_dev->delay_ns;
if (pkt_dev->delay == ULLONG_MAX) {
pkt_dev->next_tx = ktime_add_ns(ktime_now(), ULONG_MAX);
return;
}
}
Expand Down Expand Up @@ -3450,32 +3443,24 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
pkt_dev->last_ok = 0;
}

if (pkt_dev->delay_us || pkt_dev->delay_ns) {
pkt_dev->next_tx_us = getCurUs();
pkt_dev->next_tx_ns = 0;

pkt_dev->next_tx_us += pkt_dev->delay_us;
pkt_dev->next_tx_ns += pkt_dev->delay_ns;

if (pkt_dev->next_tx_ns > 1000) {
pkt_dev->next_tx_us++;
pkt_dev->next_tx_ns -= 1000;
}
}
if (pkt_dev->delay)
pkt_dev->next_tx = ktime_add_ns(ktime_now(),
pkt_dev->delay);
}
__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)) {
if (atomic_read(&(pkt_dev->skb->users)) != 1) {
u64 idle_start = getCurUs();
ktime_t idle_start = ktime_now();
while (atomic_read(&(pkt_dev->skb->users)) != 1) {
if (signal_pending(current)) {
break;
}
schedule();
}
pkt_dev->idle_acc += getCurUs() - idle_start;
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(ktime_now(),
idle_start));
}

/* Done with this */
Expand Down Expand Up @@ -3634,8 +3619,7 @@ static int pktgen_add_device(struct pktgen_thread *t, const char *ifname)
pkt_dev->max_pkt_size = ETH_ZLEN;
pkt_dev->nfrags = 0;
pkt_dev->clone_skb = pg_clone_skb_d;
pkt_dev->delay_us = pg_delay_d / 1000;
pkt_dev->delay_ns = pg_delay_d % 1000;
pkt_dev->delay = pg_delay_d;
pkt_dev->count = pg_count_d;
pkt_dev->sofar = 0;
pkt_dev->udp_src_min = 9; /* sink port */
Expand Down

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