libtraceevent: Show migrate-disable field

Commit Message

Steven Rostedt Jan. 9, 2023, 11:40 p.m. UTC

From: "Steven Rostedt (Google)" <[e-mail]>

Since Linux kernel 5.15 (specifically with the addition of 54357f0c9149c
("tracing: Add migrate-disabled counter to tracing output.")), the
common_preempt_count field of each event also held the "migrate-disable"
field in the most significant byte. This needs to be accounted for as when
the migrate disable field is set, it will show:

systemd--268     3d..3 15368.334398: rcu_dyntick:          --= 4000000000000002 4000000000000000 0x63c
systemd--268     3d..13 15368.334399: rcu_dyntick:          ++= 4000000000000000 4000000000000002 0x63c
systemd--268     3d..12 15368.334400: irq_disable:          caller=ct_irq_enter_irqson+0x17 parent=0x0
systemd--268     3d..13 15368.334400: rcu_dyntick:          --= 4000000000000002 4000000000000000 0x63c
systemd--268     3d..12 15368.334401: rcu_dyntick:          ++= 4000000000000000 4000000000000002 0x63c

Where the events above have:

   preempt-count	migrate-disable
   -------------        ---------------
	3			0
	3			1
	2			1
	3			1
	2			1

That is, in the above print of "3d..13", the '3' of the '13' is the
preempt count and the '1' is the migrate disable. But it really should be:

systemd--268     3d..3. 15368.334398: rcu_dyntick:          --= 4000000000000002 4000000000000000 0x63c
systemd--268     3d..31 15368.334399: rcu_dyntick:          ++= 4000000000000000 4000000000000002 0x63c
systemd--268     3d..21 15368.334400: irq_disable:          caller=ct_irq_enter_irqson+0x17 parent=0x0
systemd--268     3d..31 15368.334400: rcu_dyntick:          --= 4000000000000002 4000000000000000 0x63c
systemd--268     3d..21 15368.334401: rcu_dyntick:          ++= 4000000000000000 4000000000000002 0x63c

Where the migrate disabled is always displayed with a '.' when zero and
its hex count when set.

Signed-off-by: Steven Rostedt (Google) <[e-mail]>
---
 src/event-parse.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

Patch

diff --git a/src/event-parse.c b/src/event-parse.c
index 18db7fcb456d..e655087dad60 100644
--- a/src/event-parse.c
+++ b/src/event-parse.c
@@ -6768,8 +6768,13 @@  static void data_latency_format(struct tep_handle *tep, struct trace_seq *s,
 	       (hardirq && softirq) ? 'H' :
 	       hardirq ? 'h' : softirq ? 's' : '.');
 
-	if (pc)
-		trace_seq_printf(&sq, "%x", pc);
+	if (pc & 0xf)
+		trace_seq_printf(&sq, "%x", pc & 0xf);
+	else
+		trace_seq_printf(&sq, ".");
+
+	if (pc & 0xf0)
+		trace_seq_printf(&sq, "%x", pc >> 4);
 	else
 		trace_seq_printf(&sq, ".");