Roger that!
Thanks,
Ze
On Mon, Jul 31, 2023 at 11:40 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> On Wed, 26 Jul 2023 20:16:18 +0800
> Ze Gao <zegao2021@xxxxxxxxx> wrote:
>
> > Since the sched_switch tracepoint introduces a new variable to
> > report sched-out task state in symbolic char, we switch to use
> > that instead to spare from knowing internal implementations
> > in kernel.
>
> This needs to be changed to check if the "prev_state_char" field exists,
> and if not, then it must use the old method. Same for perf. The tools must
> work with older kernels.
>
> -- Steve
>
> >
> > Signed-off-by: Ze Gao <zegao@xxxxxxxxxxx>
> > ---
> > plugins/plugin_sched_switch.c | 29 ++++-------------------------
> > 1 file changed, 4 insertions(+), 25 deletions(-)
> >
> > diff --git a/plugins/plugin_sched_switch.c b/plugins/plugin_sched_switch.c
> > index 8752cae..5dbdc28 100644
> > --- a/plugins/plugin_sched_switch.c
> > +++ b/plugins/plugin_sched_switch.c
> > @@ -9,27 +9,6 @@
> > #include "event-parse.h"
> > #include "trace-seq.h"
> >
> > -static void write_state(struct trace_seq *s, int val)
> > -{
> > - const char states[] = "SDTtZXxW";
> > - int found = 0;
> > - int i;
> > -
> > - for (i = 0; i < (sizeof(states) - 1); i++) {
> > - if (!(val & (1 << i)))
> > - continue;
> > -
> > - if (found)
> > - trace_seq_putc(s, '|');
> > -
> > - found = 1;
> > - trace_seq_putc(s, states[i]);
> > - }
> > -
> > - if (!found)
> > - trace_seq_putc(s, 'R');
> > -}
> > -
> > static void write_and_save_comm(struct tep_format_field *field,
> > struct tep_record *record,
> > struct trace_seq *s, int pid)
> > @@ -97,10 +76,10 @@ static int sched_switch_handler(struct trace_seq *s,
> > trace_seq_printf(s, "%lld ", val);
> >
> > if (tep_get_field_val(s, event, "prev_prio", record, &val, 1) ==
> > 0)
> > - trace_seq_printf(s, "[%d] ", (int) val);
> > + trace_seq_printf(s, "[%d] ", (short) val);
> >
> > - if (tep_get_field_val(s, event, "prev_state", record, &val, 1)
> > == 0)
> > - write_state(s, val);
> > + if (tep_get_field_val(s, event, "prev_state_char", record,
> > &val, 1) == 0)
> > + trace_seq_putc(s, (char) val);
> >
> > trace_seq_puts(s, " ==> ");
> >
> > @@ -115,7 +94,7 @@ static int sched_switch_handler(struct trace_seq *s,
> > trace_seq_printf(s, "%lld", val);
> >
> > if (tep_get_field_val(s, event, "next_prio", record, &val, 1) ==
> > 0)
> > - trace_seq_printf(s, " [%d]", (int) val);
> > + trace_seq_printf(s, " [%d]", (short) val);
> >
> > return 0;
> > }
>
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