net_sched: add qdisc_watchdog_schedule_range_ns()

Some packet schedulers might want to add a slack
when programming hrtimers. This can reduce number
of interrupts and increase batch sizes and thus
give good xmit_more savings.

This commit adds qdisc_watchdog_schedule_range_ns()
helper, with an extra delta_ns parameter.

Legacy qdisc_watchdog_schedule_n() becomes an inline
passing a zero slack.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index 20d2c64..9092e69 100644 (file)
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -75,7 +75,15 @@ struct qdisc_watchdog {
 void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
                                 clockid_t clockid);
 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
-void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires);
+
+void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires,
+                                     u64 delta_ns);
+
+static inline void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd,
+                                             u64 expires)
+{
+       return qdisc_watchdog_schedule_range_ns(wd, expires, 0ULL);
+}
 
 static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
                                           psched_time_t expires)

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 5079412..83984be 100644 (file)
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -618,7 +618,8 @@ void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
 }
 EXPORT_SYMBOL(qdisc_watchdog_init);
 
-void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
+void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires,
+                                     u64 delta_ns)
 {
        if (test_bit(__QDISC_STATE_DEACTIVATED,
                     &qdisc_root_sleeping(wd->qdisc)->state))
@@ -628,11 +629,12 @@ void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
                return;
 
        wd->last_expires = expires;
-       hrtimer_start(&wd->timer,
-                     ns_to_ktime(expires),
-                     HRTIMER_MODE_ABS_PINNED);
+       hrtimer_start_range_ns(&wd->timer,
+                              ns_to_ktime(expires),
+                              delta_ns,
+                              HRTIMER_MODE_ABS_PINNED);
 }
-EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
+EXPORT_SYMBOL(qdisc_watchdog_schedule_range_ns);
 
 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
 {