On Fri, 12 Jul 2019 11:05:06 -0500
Tom Zanussi <zanu...@kernel.org> 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 <zanu...@kernel.org>
Why is this Signed-off-by Tom? Tom, did you author part of this??
-- Steve
> > Signed-off-by: Zhengjun Xing <zhengjun.x...@linux.intel.com>
>
> 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++;
> > }
> > }
