Re: [PATCH] tracing: fix missing osnoise tracer on max_latency

[Jackie Liu]

在 2021/9/22 上午10:40, Steven Rostedt 写道:
> On Wed, 22 Sep 2021 10:26:24 +0800
> Jackie Liu <liu.yun@xxxxxxxxx> wrote:
>
> > > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> > > > index 7896d30d90f7..d7e3ed82fafd 100644
> > > > --- a/kernel/trace/trace.c
> > > > +++ b/kernel/trace/trace.c
> > > > @@ -1744,11 +1744,7 @@ void latency_fsnotify(struct trace_array *tr)
> > > >    	irq_work_queue(&tr->fsnotify_irqwork);
> > > >    }
> > > >    
> > > > -/*
> > > > - * (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
> > > > - *  defined(CONFIG_FSNOTIFY)
> > > > - */
> > > > -#else
> > > > +#else /* LATENCY_FS_NOTIFY  >>
> > > >    #define trace_create_maxlat_file(tr, d_tracer)				\
> > > >    	trace_create_file("tracing_max_latency", 0644, d_tracer,	\
> > >
> > > To clean this up even better, we should add here:
> > >
> > > #elif defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) \
> > > 	|| defined(CONFIG_OSNOISE_TRACER)
> >
> > This place should need to use LATENCY_FS_NOTIFY, because not only these
> > three Traces, we also need to pay attention to CONFIG_FSNOTIFY, at
> > least, we should not change the original meaning.
> >
> > How about this:
> >
> > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> > index 7896d30d90f7..6a88d03c6d3b 100644
> > --- a/kernel/trace/trace.c
> > +++ b/kernel/trace/trace.c
> > @@ -1744,16 +1744,14 @@ void latency_fsnotify(struct trace_array *tr)
> >           irq_work_queue(&tr->fsnotify_irqwork);
> >    }
> >
> > -/*
> > - * (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
> > - *  defined(CONFIG_FSNOTIFY)
> > - */
> > -#else
> > +#elif defined(LATENCY_FS_NOTIFY)
>
> Um, but isn't the #if before the #else:
>
>    #ifdef LATENCY_FS_NOTIFY
>
> ?
>
> Then, here we have:
>
>
> #ifdef LATENCY_FS_NOTIFY
>
> [..]
>
> #elif defined(LATENCY_FS_NOTIFY)
>
> // this will never be called.
>
> That doesn't make any sense.
>
> -- Steve

Thanks Steve, I see.  :)

--
BR, Jackie Liu

> >    #define trace_create_maxlat_file(tr, d_tracer)                         \
> >           trace_create_file("tracing_max_latency", 0644, d_tracer,        \
> >                             &tr->max_latency, &tracing_max_lat_fops)
> >
> > +#else
> > +#define trace_create_maxlat_file(tr, d_tracer)  do { } while (0)
> >    #endif
> >
> >    #ifdef CONFIG_TRACER_MAX_TRACE
> > @@ -9473,9 +9471,7 @@ init_tracer_tracefs(struct trace_array *tr, struct
> > dentry *d_tracer)
> >
> >           create_trace_options_dir(tr);
> >
> > -#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
> >           trace_create_maxlat_file(tr, d_tracer);
> > -#endif
> >
> >           if (ftrace_create_function_files(tr, d_tracer))
> >                   MEM_FAIL(1, "Could not allocate function filter files");
> >
> >
> > ==
> > What do you think? If there is no problem, I will send V2.