On Wed, 2024-02-21 at 17:25 +0100, Benjamin Tissoires wrote: [...] > @@ -1282,7 +1333,7 @@ BPF_CALL_3(bpf_timer_start, struct bpf_timer_kern *, timer, u64, nsecs, u64, fla > > if (in_nmi()) > return -EOPNOTSUPP; > - if (flags & ~(BPF_F_TIMER_ABS | BPF_F_TIMER_CPU_PIN)) > + if (flags & ~(BPF_F_TIMER_ABS | BPF_F_TIMER_CPU_PIN | BPF_F_TIMER_SLEEPABLE)) > return -EINVAL; > __bpf_spin_lock_irqsave(&timer->lock); > t = timer->timer; > @@ -1299,7 +1350,10 @@ BPF_CALL_3(bpf_timer_start, struct bpf_timer_kern *, timer, u64, nsecs, u64, fla > if (flags & BPF_F_TIMER_CPU_PIN) > mode |= HRTIMER_MODE_PINNED; > > - hrtimer_start(&t->timer, ns_to_ktime(nsecs), mode); > + if (flags & BPF_F_TIMER_SLEEPABLE) > + schedule_work(&t->work); > + else > + hrtimer_start(&t->timer, ns_to_ktime(nsecs), mode); It looks like nsecs is simply ignored for sleepable timers. Should this be hrtimer_start() that waits nsecs and schedules work, or schedule_delayed_work()? (but it takes delay in jiffies, which is probably too coarse). Sorry if I miss something.