On 08/05/2016 04:44 PM, Steven Rostedt wrote: > On Fri, 5 Aug 2016 16:25:21 +0200 > Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote: > >> * Steven Rostedt | 2016-08-04 10:57:09 [-0400]: >> >>> diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c >>> new file mode 100644 >>> index 000000000000..08dfabe4e862 >>> --- /dev/null >>> +++ b/kernel/trace/trace_hwlat.c >> … >>> +/* Macros to encapsulate the time capturing infrastructure */ >>> +#define time_type u64 >>> +#define time_get() trace_clock_local() >>> +#define time_to_us(x) div_u64(x, 1000) >>> +#define time_sub(a, b) ((a) - (b)) >>> +#define init_time(a, b) (a = b) >>> +#define time_u64(a) a >> >> Do we need a macro for this? In the old code we could choose between >> CONFIG_TRACING but now we don't. >> > > Probably not, I kept it for two reasons. 1) to keep the same logic as > what was in PREEMPT_RT, and 2) in case we can come up with a better > clock. I assumed it was a leftover. > But it's not that important. Should it be nuked? They do somewhat make > the code easier to read. that time_get() is close to ktime_get() which is almost u64 nowadays. So it might not be that cool for upstream. A hwlat prefix makes the whole thing not prettier. 1. PREEMPT_RT. Do I need any changes? I assumed I could keep this 1:1 (once it is merged) and throw the current hwlat out. 2. a better clock is an argument. But why would you have a better clock for hwlat and not for the whole tracing infrastructure? If you want to keep it, keep it. I just assumed it was a leftover. > > -- Steve Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
