On Tue, 20 Sep 2016, Binoy Jayan wrote: > +#ifdef CONFIG_TRACE_DELAYED_TIMER_OFFSETS > +static inline void latency_hrtimer_timing_start(struct hrtimer *timer, > + struct hrtimer_clock_base *new_base, > + ktime_t tim) > +{ > + ktime_t now = new_base->get_time(); > + > + if (ktime_to_ns(tim) < ktime_to_ns(now)) > + timer->tim_expiry = now; > + else > + timer->tim_expiry = ktime_set(0, 0);
You still fail to explain why this get_time() magic is required. This is executed unconditionally when the config switch is enabled and does not depend on whether the trace functionality is enabled or not. So you are imposing the extra get_time() call, which can be expensive depending on the underlying hardware, on every hrtimer start invocation. Tracing is supposed to have ZERO impact when it is not used and even when it's in use then the impact should be kept as low as possible. The above does none of that. Neither did you provide a proper rationale for this infrastructure in the changelog. You can repost that over and over and it will not go anywhere if you don't start to address the review comments I give you. Thanks, tglx