[RFC PATCH v3 6/6] libtraceevent: prefer to use prev_state_char introduced in sched_switch
From: Ze Gao <hidden>
Date: 2023-08-01 09:02:38
Also in:
linux-perf-users, lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
Since the sched_switch tracepoint introduces a new variable to report sched-out task state in symbolic char, we prefer to use it to spare from knowing internal implementations in kernel. Also we keep the old parsing logic intact but sync the state char array with the latest kernel. Signed-off-by: Ze Gao <redacted> --- plugins/plugin_sched_switch.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/plugins/plugin_sched_switch.c b/plugins/plugin_sched_switch.c
index 8752cae..4c57322 100644
--- a/plugins/plugin_sched_switch.c
+++ b/plugins/plugin_sched_switch.c@@ -11,7 +11,7 @@ static void write_state(struct trace_seq *s, int val) { - const char states[] = "SDTtZXxW"; + const char states[] = "SDTtXZPIp"; int found = 0; int i;
@@ -99,7 +99,12 @@ static int sched_switch_handler(struct trace_seq *s, if (tep_get_field_val(s, event, "prev_prio", record, &val, 1) == 0) trace_seq_printf(s, "[%d] ", (int) val); - if (tep_get_field_val(s, event, "prev_state", record, &val, 1) == 0) + //find if has prev_state_char, otherwise fallback to prev_state + if (tep_find_field(event, "prev_state_char")) { + if (tep_get_field_val(s, event, "prev_state_char", record, &val, 1) == 0) + trace_seq_putc(s, (char) val); + } + else if (tep_get_field_val(s, event, "prev_state", record, &val, 1) == 0) write_state(s, val); trace_seq_puts(s, " ==> ");
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2.40.1