Re: [PATCH v3] trace:Add "gfp_t" support in synthetic_events

[Xing Zhengjun]

 Hi Steve,

On 8/13/2019 11:04 AM, Steven Rostedt wrote:
> On Tue, 13 Aug 2019 09:04:28 +0800
> Xing Zhengjun <zhengjun.xing@xxxxxxxxxxxxxxx> wrote:
>
> > Hi Steve,
> >
> >      Could you help to review? Thanks.
>
> Thanks for the ping. Yes, I'll take a look at it. I'll be pulling in a
> lot of patches that have queued up.
>
> -- Steve

Could you help to review? Thanks.

> > On 7/13/2019 12:05 AM, Tom Zanussi wrote:
> > > Hi Zhengjun,
> > >
> > > On Fri, 2019-07-12 at 09:53 +0800, Zhengjun Xing wrote:
> > > > Add "gfp_t" support in synthetic_events, then the "gfp_t" type
> > > > parameter in some functions can be traced.
> > > >
> > > > Prints the gfp flags as hex in addition to the human-readable flag
> > > > string.  Example output:
> > > >
> > > >     whoopsie-630 [000] ...1 78.969452: testevent: bar=b20
> > > > (GFP_ATOMIC|__GFP_ZERO)
> > > >       rcuc/0-11  [000] ...1 81.097555: testevent: bar=a20 (GFP_ATOMIC)
> > > >       rcuc/0-11  [000] ...1 81.583123: testevent: bar=a20 (GFP_ATOMIC)
> > > >
> > > > Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx>
> > > > Signed-off-by: Zhengjun Xing <zhengjun.xing@xxxxxxxxxxxxxxx>
> > >
> > > Looks good to me, thanks!
> > >
> > > Tom
> > >    
> > > > ---
> > > >    kernel/trace/trace_events_hist.c | 19 +++++++++++++++++++
> > > >    1 file changed, 19 insertions(+)
> > > >
> > > > diff --git a/kernel/trace/trace_events_hist.c
> > > > b/kernel/trace/trace_events_hist.c
> > > > index ca6b0dff60c5..30f0f32aca62 100644
> > > > --- a/kernel/trace/trace_events_hist.c
> > > > +++ b/kernel/trace/trace_events_hist.c
> > > > @@ -13,6 +13,10 @@
> > > >    #include <linux/rculist.h>
> > > >    #include <linux/tracefs.h>
> > > >    
> > > > +/* for gfp flag names */
> > > > +#include <linux/trace_events.h>
> > > > +#include <trace/events/mmflags.h>
> > > > +
> > > >    #include "tracing_map.h"
> > > >    #include "trace.h"
> > > >    #include "trace_dynevent.h"
> > > > @@ -752,6 +756,8 @@ static int synth_field_size(char *type)
> > > >    		size = sizeof(unsigned long);
> > > >    	else if (strcmp(type, "pid_t") == 0)
> > > >    		size = sizeof(pid_t);
> > > > +	else if (strcmp(type, "gfp_t") == 0)
> > > > +		size = sizeof(gfp_t);
> > > >    	else if (synth_field_is_string(type))
> > > >    		size = synth_field_string_size(type);
> > > >    
> > > > @@ -792,6 +798,8 @@ static const char *synth_field_fmt(char *type)
> > > >    		fmt = "%lu";
> > > >    	else if (strcmp(type, "pid_t") == 0)
> > > >    		fmt = "%d";
> > > > +	else if (strcmp(type, "gfp_t") == 0)
> > > > +		fmt = "%x";
> > > >    	else if (synth_field_is_string(type))
> > > >    		fmt = "%s";
> > > >    
> > > > @@ -834,9 +842,20 @@ static enum print_line_t
> > > > print_synth_event(struct trace_iterator *iter,
> > > >    					 i == se->n_fields - 1 ? ""
> > > > : " ");
> > > >    			n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
> > > >    		} else {
> > > > +			struct trace_print_flags __flags[] = {
> > > > +			    __def_gfpflag_names, {-1, NULL} };
> > > > +
> > > >    			trace_seq_printf(s, print_fmt, se-
> > > > > fields[i]->name,
> > > >    					 entry->fields[n_u64],
> > > >    					 i == se->n_fields - 1 ? ""
> > > > : " ");
> > > > +
> > > > +			if (strcmp(se->fields[i]->type, "gfp_t") ==
> > > > 0) {
> > > > +				trace_seq_puts(s, " (");
> > > > +				trace_print_flags_seq(s, "|",
> > > > +						      entry-
> > > > > fields[n_u64],
> > > > +						      __flags);
> > > > +				trace_seq_putc(s, ')');
> > > > +			}
> > > >    			n_u64++;
> > > >    		}
> > > >    	}

--
Zhengjun Xing