[for-linus][PATCH 2/7] trace/osnoise: Add a header with PREEMPT_RT additional fields

Steven Rostedt
2021-08-12T01:14:02Z

Some extra flags are printed to the trace header when using the
PREEMPT_RT config. The extra flags are: need-resched-lazy,
preempt-lazy-depth, and migrate-disable.

Without printing these fields, the osnoise specific fields are
shifted by three positions, for example:

# tracer: osnoise
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth MAX
# || / SINGLE Interference counters:
# |||| RUNTIME NOISE %% OF CPU NOISE +-----------------------------+
# TASK-PID CPU# |||| TIMESTAMP IN US IN US AVAILABLE IN US HW NMI IRQ SIRQ THREAD
# | | | |||| | | | | | | | | | |
<...>-741 [000] ....... 1105.690909: 1000000 234 99.97660 36 21 0 1001 22 3
<...>-742 [001] ....... 1105.691923: 1000000 281 99.97190 197 7 0 1012 35 14
<...>-743 [002] ....... 1105.691958: 1000000 1324 99.86760 118 11 0 1016 155 143
<...>-744 [003] ....... 1105.691998: 1000000 109 99.98910 21 4 0 1004 33 7
<...>-745 [004] ....... 1105.692015: 1000000 2023 99.79770 97 37 0 1023 52 18

Add a new header for osnoise with the missing fields, to be used
when the PREEMPT_RT is enabled.

Link: https://lkml.kernel.org/r/1f03289d2a51fde5a58c2e7def063dc630820ad1.1626598844.git.bristot@kernel.org

Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_osnoise.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 912036d6a668..cbdda2fe4926 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -253,10 +253,40 @@ static struct osnoise_data {
*/
static bool osnoise_busy;

+#ifdef CONFIG_PREEMPT_RT
/*
* Print the osnoise header info.
*/
static void print_osnoise_headers(struct seq_file *s)
+{
+ if (osnoise_data.tainted)
+ seq_puts(s, "# osnoise is tainted!\n");
+
+ seq_puts(s, "# _-------=> irqs-off\n");
+ seq_puts(s, "# / _------=> need-resched\n");
+ seq_puts(s, "# | / _-----=> need-resched-lazy\n");
+ seq_puts(s, "# || / _----=> hardirq/softirq\n");
+ seq_puts(s, "# ||| / _---=> preempt-depth\n");
+ seq_puts(s, "# |||| / _--=> preempt-lazy-depth\n");
+ seq_puts(s, "# ||||| / _-=> migrate-disable\n");
+
+ seq_puts(s, "# |||||| / ");
+ seq_puts(s, " MAX\n");
+
+ seq_puts(s, "# ||||| / ");
+ seq_puts(s, " SINGLE Interference counters:\n");
+
+ seq_puts(s, "# ||||||| RUNTIME ");
+ seq_puts(s, " NOISE %% OF CPU NOISE +-----------------------------+\n");
+
+ seq_puts(s, "# TASK-PID CPU# ||||||| TIMESTAMP IN US ");
+ seq_puts(s, " IN US AVAILABLE IN US HW NMI IRQ SIRQ THREAD\n");
+
+ seq_puts(s, "# | | | ||||||| | | ");
+ seq_puts(s, " | | | | | | | |\n");
+}
+#else /* CONFIG_PREEMPT_RT */
+static void print_osnoise_headers(struct seq_file *s)
{
if (osnoise_data.tainted)
seq_puts(s, "# osnoise is tainted!\n");
@@ -279,6 +309,7 @@ static void print_osnoise_headers(struct seq_file *s)
seq_puts(s, "# | | | |||| | | ");
seq_puts(s, " | | | | | | | |\n");
}
+#endif /* CONFIG_PREEMPT_RT */

/*
* osnoise_taint - report an osnoise error.
--
2.30.2