* [PATCH] trace-cmd report: Explain the '-l' option better in the man page
@ 2022-06-07 15:30 Steven Rostedt
2022-06-07 16:17 ` Julia Lawall
0 siblings, 1 reply; 3+ messages in thread
From: Steven Rostedt @ 2022-06-07 15:30 UTC (permalink / raw)
To: Linux Trace Devel; +Cc: Julia Lawall
From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
The '-l' option shows latency information of each event. It is not well
documented. Update the man page to show what the cryptic values mean.
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216069
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
.../trace-cmd/trace-cmd-report.1.txt | 39 +++++++++++++++----
1 file changed, 32 insertions(+), 7 deletions(-)
diff --git a/Documentation/trace-cmd/trace-cmd-report.1.txt b/Documentation/trace-cmd/trace-cmd-report.1.txt
index df60dd87d979..ccf635fb664b 100644
--- a/Documentation/trace-cmd/trace-cmd-report.1.txt
+++ b/Documentation/trace-cmd/trace-cmd-report.1.txt
@@ -221,13 +221,38 @@ OPTIONS
<idle>-0 0d.h1. 106467.859747: function: ktime_get <-- tick_check_idle
----
- The 0d.h1. denotes this information. The first character is never a '.'
- and represents what CPU the trace was recorded on (CPU 0). The 'd' denotes
- that interrupts were disabled. The 'h' means that this was called inside
- an interrupt handler. The '1' is the preemption disabled (preempt_count)
- was set to one. The two '.'s are "need_resched" flag and kernel lock
- counter. If the "need_resched" flag is set, then that character would be a
- 'N'.
+ The 0d.h1. denotes this information.
+
+ It starts with a number. This represents the CPU number that the event occurred
+ on.
+
+ The second character is one of the following:
+
+ 'd' - Interrupts are disabled
+ '.' - Interrupts are enabled
+ 'X' - Has flags that are not yet known by trace-cmd
+
+ The third character is the "need rescheduling" flag.
+
+ 'N' - A schedule is set to take place
+ '.' - No scheduling is set
+
+ The forth character represents the context the event was in when it triggered
+
+ 'h' - Hard interrupt context
+ 's' - Soft interrupt context
+ 'H' - Hard interrupt context that interrupted a soft interrupt
+ '.' - Normal context
+
+ The next is a number (should be less than 10), that represents the preemption
+ depth (the number of times preempt_disable() is called without preempt_enable()).
+ '.' means preemption is enabled.
+
+ On some systems, "migrate disable" may exist, in which case a number will be
+ shown for that, or '.' meaning migration is enabled.
+
+ If lockdep in enabled on the system, then the number represents the depth of
+ locks that are held when the event triggered. '.' means no locks are held.
*-w*::
If both the 'sched_switch' and 'sched_wakeup' events are enabled, then
--
2.35.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] trace-cmd report: Explain the '-l' option better in the man page
2022-06-07 15:30 [PATCH] trace-cmd report: Explain the '-l' option better in the man page Steven Rostedt
@ 2022-06-07 16:17 ` Julia Lawall
2022-06-07 16:24 ` Steven Rostedt
0 siblings, 1 reply; 3+ messages in thread
From: Julia Lawall @ 2022-06-07 16:17 UTC (permalink / raw)
To: Steven Rostedt; +Cc: Linux Trace Devel
On Tue, 7 Jun 2022, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
>
> The '-l' option shows latency information of each event. It is not well
> documented. Update the man page to show what the cryptic values mean.
>
> Reported-by: Julia Lawall <julia.lawall@inria.fr>
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216069
> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
> ---
> .../trace-cmd/trace-cmd-report.1.txt | 39 +++++++++++++++----
> 1 file changed, 32 insertions(+), 7 deletions(-)
>
> diff --git a/Documentation/trace-cmd/trace-cmd-report.1.txt b/Documentation/trace-cmd/trace-cmd-report.1.txt
> index df60dd87d979..ccf635fb664b 100644
> --- a/Documentation/trace-cmd/trace-cmd-report.1.txt
> +++ b/Documentation/trace-cmd/trace-cmd-report.1.txt
> @@ -221,13 +221,38 @@ OPTIONS
> <idle>-0 0d.h1. 106467.859747: function: ktime_get <-- tick_check_idle
> ----
>
> - The 0d.h1. denotes this information. The first character is never a '.'
> - and represents what CPU the trace was recorded on (CPU 0). The 'd' denotes
> - that interrupts were disabled. The 'h' means that this was called inside
> - an interrupt handler. The '1' is the preemption disabled (preempt_count)
> - was set to one. The two '.'s are "need_resched" flag and kernel lock
> - counter. If the "need_resched" flag is set, then that character would be a
> - 'N'.
> + The 0d.h1. denotes this information.
> +
> + It starts with a number. This represents the CPU number that the event occurred
> + on.
> +
> + The second character is one of the following:
> +
> + 'd' - Interrupts are disabled
> + '.' - Interrupts are enabled
> + 'X' - Has flags that are not yet known by trace-cmd
> +
> + The third character is the "need rescheduling" flag.
> +
> + 'N' - A schedule is set to take place
> + '.' - No scheduling is set
> +
> + The forth character represents the context the event was in when it triggered
Thanks for the extra detail.
Forth should be fourth.
julia
> +
> + 'h' - Hard interrupt context
> + 's' - Soft interrupt context
> + 'H' - Hard interrupt context that interrupted a soft interrupt
> + '.' - Normal context
> +
> + The next is a number (should be less than 10), that represents the preemption
> + depth (the number of times preempt_disable() is called without preempt_enable()).
> + '.' means preemption is enabled.
> +
> + On some systems, "migrate disable" may exist, in which case a number will be
> + shown for that, or '.' meaning migration is enabled.
> +
> + If lockdep in enabled on the system, then the number represents the depth of
> + locks that are held when the event triggered. '.' means no locks are held.
>
> *-w*::
> If both the 'sched_switch' and 'sched_wakeup' events are enabled, then
> --
> 2.35.1
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] trace-cmd report: Explain the '-l' option better in the man page
2022-06-07 16:17 ` Julia Lawall
@ 2022-06-07 16:24 ` Steven Rostedt
0 siblings, 0 replies; 3+ messages in thread
From: Steven Rostedt @ 2022-06-07 16:24 UTC (permalink / raw)
To: Julia Lawall; +Cc: Linux Trace Devel
On Tue, 7 Jun 2022 18:17:22 +0200 (CEST)
Julia Lawall <julia.lawall@inria.fr> wrote:
> > + The forth character represents the context the event was in when it triggered
>
> Thanks for the extra detail.
>
> Forth should be fourth.
Bah, when people ask me what language is my mother tongue, I simply reply
"C"
Thanks, will update.
-- Steve
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-06-07 15:30 [PATCH] trace-cmd report: Explain the '-l' option better in the man page Steven Rostedt
2022-06-07 16:17 ` Julia Lawall
2022-06-07 16:24 ` Steven Rostedt
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