Re: timers: Make flags output in the timer_start tracepoint useful

From: Steven Rostedt
Date: Fri Feb 10 2017 - 09:51:44 EST


On Fri, 10 Feb 2017 15:37:11 +0100 (CET)
Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:

> > > --- a/include/trace/events/timer.h
> > > +++ b/include/trace/events/timer.h
> > > @@ -36,6 +36,13 @@ DEFINE_EVENT(timer_class, timer_init,
> > > TP_ARGS(timer)
> > > );
> > >
> > > +#define decode_timer_flags(flags) \
> > > + __print_flags(flags, "|", \
> > > + { TIMER_MIGRATING, "M" }, \
> > > + { TIMER_DEFERRABLE, "D" }, \
> > > + { TIMER_PINNED, "P" }, \
> > > + { TIMER_IRQSAFE, "I" })
> > > +
> > > /**
> > > * timer_start - called when the timer is started
> > > * @timer: pointer to struct timer_list
> > > @@ -65,9 +72,12 @@ TRACE_EVENT(timer_start,
> > > __entry->flags = flags;
> > > ),
> > >
> > > - TP_printk("timer=%p function=%pf expires=%lu [timeout=%ld] flags=0x%08x",
> > > + TP_printk("timer=%p function=%pf expires=%lu [timeout=%ld] cpu=%u idx=%u flags=%s",
> > > __entry->timer, __entry->function, __entry->expires,
> > > - (long)__entry->expires - __entry->now, __entry->flags)
> > > + (long)__entry->expires - __entry->now,
> > > + __entry->flags & TIMER_CPUMASK,
> > > + __entry->flags >> TIMER_ARRAYSHIFT,
> > > + decode_timer_flags(__entry->flags & TIMER_TRACE_FLAGMASK))
> >
> > Hi Thomas,
> >
> > This all looks good, but I can't find TIMER_TRACE_FLAGMASK. Was that
> > added by another patch?
>
> -ENO_QUILT_REFRESH ....

I'm wondering if it wouldn't just make sense to add another mask in
include/linux/timer.h along with the other TIMER macros?

#define TIMER_TYPEMASK 0x003C0000

Or some other name?

-- Steve