diff mbox series

[v3,1/2] tracing: support "bool" type in synthetic trace events

Message ID 20201009220524.485102-2-axelrasmussen@google.com (mailing list archive)
State New, archived
Headers show
Series Add tracepoints around mmap_lock acquisition | expand

Commit Message

Axel Rasmussen Oct. 9, 2020, 10:05 p.m. UTC 
It's common [1] to define tracepoint fields as "bool" when they contain
a true / false value. Currently, defining a synthetic event with a
"bool" field yields EINVAL. It's possible to work around this by using
e.g. u8 (assuming sizeof(bool) is 1, and bool is unsigned; if either of
these properties don't match, you get EINVAL [2]).

Supporting "bool" explicitly makes hooking this up easier and more
portable for userspace.

[1]: grep -r "bool" include/trace/events/
[2]: check_synth_field() in kernel/trace/trace_events_hist.c

Acked-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
---
 kernel/trace/trace_events_synth.c | 4 ++++
 1 file changed, 4 insertions(+)

--
2.28.0.1011.ga647a8990f-goog

Comments

Steven Rostedt Oct. 12, 2020, 2:15 p.m. UTC | #1 
Tom,

Can you ack this patch for me?

-- Steve


On Fri,  9 Oct 2020 15:05:23 -0700
Axel Rasmussen <axelrasmussen@google.com> wrote:

> It's common [1] to define tracepoint fields as "bool" when they contain
> a true / false value. Currently, defining a synthetic event with a
> "bool" field yields EINVAL. It's possible to work around this by using
> e.g. u8 (assuming sizeof(bool) is 1, and bool is unsigned; if either of
> these properties don't match, you get EINVAL [2]).
> 
> Supporting "bool" explicitly makes hooking this up easier and more
> portable for userspace.
> 
> [1]: grep -r "bool" include/trace/events/
> [2]: check_synth_field() in kernel/trace/trace_events_hist.c
> 
> Acked-by: Michel Lespinasse <walken@google.com>
> Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
> ---
>  kernel/trace/trace_events_synth.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
> index 8e1974fbad0e..8f94c84349a6 100644
> --- a/kernel/trace/trace_events_synth.c
> +++ b/kernel/trace/trace_events_synth.c
> @@ -234,6 +234,8 @@ static int synth_field_size(char *type)
>  		size = sizeof(long);
>  	else if (strcmp(type, "unsigned long") == 0)
>  		size = sizeof(unsigned long);
> +	else if (strcmp(type, "bool") == 0)
> +		size = sizeof(bool);
>  	else if (strcmp(type, "pid_t") == 0)
>  		size = sizeof(pid_t);
>  	else if (strcmp(type, "gfp_t") == 0)
> @@ -276,6 +278,8 @@ static const char *synth_field_fmt(char *type)
>  		fmt = "%ld";
>  	else if (strcmp(type, "unsigned long") == 0)
>  		fmt = "%lu";
> +	else if (strcmp(type, "bool") == 0)
> +		fmt = "%d";
>  	else if (strcmp(type, "pid_t") == 0)
>  		fmt = "%d";
>  	else if (strcmp(type, "gfp_t") == 0)
> --
> 2.28.0.1011.ga647a8990f-goog
Tom Zanussi Oct. 12, 2020, 2:26 p.m. UTC | #2 
Hi Steve,

Looks ok to me.

Acked-by: Tom Zanussi <zanussi@kernel.org>

Thanks,

Tom


On Mon, 2020-10-12 at 10:15 -0400, Steven Rostedt wrote:
> Tom,
> 
> Can you ack this patch for me?
> 
> -- Steve
> 
> 
> On Fri,  9 Oct 2020 15:05:23 -0700
> Axel Rasmussen <axelrasmussen@google.com> wrote:
> 
> > It's common [1] to define tracepoint fields as "bool" when they
> > contain
> > a true / false value. Currently, defining a synthetic event with a
> > "bool" field yields EINVAL. It's possible to work around this by
> > using
> > e.g. u8 (assuming sizeof(bool) is 1, and bool is unsigned; if
> > either of
> > these properties don't match, you get EINVAL [2]).
> > 
> > Supporting "bool" explicitly makes hooking this up easier and more
> > portable for userspace.
> > 
> > [1]: grep -r "bool" include/trace/events/
> > [2]: check_synth_field() in kernel/trace/trace_events_hist.c
> > 
> > Acked-by: Michel Lespinasse <walken@google.com>
> > Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
> > ---
> >  kernel/trace/trace_events_synth.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> > 
> > diff --git a/kernel/trace/trace_events_synth.c
> > b/kernel/trace/trace_events_synth.c
> > index 8e1974fbad0e..8f94c84349a6 100644
> > --- a/kernel/trace/trace_events_synth.c
> > +++ b/kernel/trace/trace_events_synth.c
> > @@ -234,6 +234,8 @@ static int synth_field_size(char *type)
> >  		size = sizeof(long);
> >  	else if (strcmp(type, "unsigned long") == 0)
> >  		size = sizeof(unsigned long);
> > +	else if (strcmp(type, "bool") == 0)
> > +		size = sizeof(bool);
> >  	else if (strcmp(type, "pid_t") == 0)
> >  		size = sizeof(pid_t);
> >  	else if (strcmp(type, "gfp_t") == 0)
> > @@ -276,6 +278,8 @@ static const char *synth_field_fmt(char *type)
> >  		fmt = "%ld";
> >  	else if (strcmp(type, "unsigned long") == 0)
> >  		fmt = "%lu";
> > +	else if (strcmp(type, "bool") == 0)
> > +		fmt = "%d";
> >  	else if (strcmp(type, "pid_t") == 0)
> >  		fmt = "%d";
> >  	else if (strcmp(type, "gfp_t") == 0)
> > --
> > 2.28.0.1011.ga647a8990f-goog
> 
>
Steven Rostedt Oct. 12, 2020, 2:46 p.m. UTC | #3 
On Mon, 12 Oct 2020 09:26:13 -0500
Tom Zanussi <zanussi@kernel.org> wrote:

> Hi Steve,
> 
> Looks ok to me.
> 
> Acked-by: Tom Zanussi <zanussi@kernel.org>

Great!

I'll pull this patch into my tree. It doesn't look like patch 2/2 is
dependent on this and these two can go through different trees.

Is everyone OK if I take this patch through my tree?

-- Steve
Axel Rasmussen Oct. 12, 2020, 4:23 p.m. UTC | #4 
On Mon, Oct 12, 2020 at 7:46 AM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Mon, 12 Oct 2020 09:26:13 -0500
> Tom Zanussi <zanussi@kernel.org> wrote:
>
> > Hi Steve,
> >
> > Looks ok to me.
> >
> > Acked-by: Tom Zanussi <zanussi@kernel.org>
>
> Great!
>
> I'll pull this patch into my tree. It doesn't look like patch 2/2 is
> dependent on this and these two can go through different trees.
>
> Is everyone OK if I take this patch through my tree?

Sounds good to me. You're right that there is no compile-time
dependency between the two patches.

Thanks!

>
> -- Steve
David Rientjes Oct. 13, 2020, 7:41 p.m. UTC | #5 
On Fri, 9 Oct 2020, Axel Rasmussen wrote:

> It's common [1] to define tracepoint fields as "bool" when they contain
> a true / false value. Currently, defining a synthetic event with a
> "bool" field yields EINVAL. It's possible to work around this by using
> e.g. u8 (assuming sizeof(bool) is 1, and bool is unsigned; if either of
> these properties don't match, you get EINVAL [2]).
> 
> Supporting "bool" explicitly makes hooking this up easier and more
> portable for userspace.
> 
> [1]: grep -r "bool" include/trace/events/
> [2]: check_synth_field() in kernel/trace/trace_events_hist.c
> 
> Acked-by: Michel Lespinasse <walken@google.com>
> Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>

Acked-by: David Rientjes <rientjes@google.com>
diff mbox series

Patch

diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 8e1974fbad0e..8f94c84349a6 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -234,6 +234,8 @@  static int synth_field_size(char *type)
 		size = sizeof(long);
 	else if (strcmp(type, "unsigned long") == 0)
 		size = sizeof(unsigned long);
+	else if (strcmp(type, "bool") == 0)
+		size = sizeof(bool);
 	else if (strcmp(type, "pid_t") == 0)
 		size = sizeof(pid_t);
 	else if (strcmp(type, "gfp_t") == 0)
@@ -276,6 +278,8 @@  static const char *synth_field_fmt(char *type)
 		fmt = "%ld";
 	else if (strcmp(type, "unsigned long") == 0)
 		fmt = "%lu";
+	else if (strcmp(type, "bool") == 0)
+		fmt = "%d";
 	else if (strcmp(type, "pid_t") == 0)
 		fmt = "%d";
 	else if (strcmp(type, "gfp_t") == 0)