Hi Viresh,
On 09/07/14 07:55, Viresh Kumar wrote:
hrtimer_start*() family never fails to enqueue a hrtimer to a clock-base. The only special case is when the hrtimer was in past. If it is getting enqueued to local CPUs's clock-base, we raise a softirq and exit, else we handle that on next interrupt on remote CPU.
At several places in the kernel, we try to make sure if hrtimer was added properly or not by calling hrtimer_active(), like:
hrtimer_start(timer, expires, mode); if (hrtimer_active(timer)) { /* Added successfully */ } else { /* Was added in the past */ }
As hrtimer_start*() never fails, hrtimer_active() is guaranteed to return '1'. So, there is no point calling hrtimer_active().
This patch updates net core to get this fixed.
Cc: "David S. Miller" davem@davemloft.net Cc: netdev@vger.kernel.org Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
net/core/pktgen.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/net/core/pktgen.c b/net/core/pktgen.c index fc17a9d..f911acd 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -2186,8 +2186,6 @@ static void spin(struct pktgen_dev *pkt_dev, ktime_t spin_until) 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();
I think this if condition can also be removed. hrtimer_init_sleeper copies the supplied task_struct * to the timer, which in this case is 'current'. The check is likely to be there in case of !active case you removed.
--Chris