Which was, actually, a bug in timers - on older kernel, monotonic timer is missing and the other implementation started with now == 0, which collides with usage 0 as a special value in timer->expires field.
Which was, actually, a bug in timers - on older kernel, monotonic timer is missing and the other implementation started with now == 0, which collides with usage 0 as a special value in timer->expires field.