2024-03-14 14:42:20

by Ali Zahraee

[permalink] [raw]
Subject: [PATCH] Documentation: tracing: update format of sched_wakeup in example

The format of the sched_wakeup event is used as an example in the
documentation. But the given format is obsolete. This patch updates the
format in the example to match the current format of this event.

Signed-off-by: Ali Zahraee <[email protected]>
---
Documentation/trace/events.rst | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/Documentation/trace/events.rst b/Documentation/trace/events.rst
index 759907c20e75..65fe205c95e6 100644
--- a/Documentation/trace/events.rst
+++ b/Documentation/trace/events.rst
@@ -129,24 +129,25 @@ event::
# cat /sys/kernel/tracing/events/sched/sched_wakeup/format

name: sched_wakeup
- ID: 60
+ ID: 70
format:
field:unsigned short common_type; offset:0; size:2;
+ signed:0;
field:unsigned char common_flags; offset:2; size:1;
- field:unsigned char common_preempt_count; offset:3; size:1;
- field:int common_pid; offset:4; size:4;
- field:int common_tgid; offset:8; size:4;
+ signed:0;
+ field:unsigned char common_preempt_count; offset:3;
+ size:1; signed:0;
+ field:int common_pid; offset:4; size:4; signed:1;

- field:char comm[TASK_COMM_LEN]; offset:12; size:16;
- field:pid_t pid; offset:28; size:4;
- field:int prio; offset:32; size:4;
- field:int success; offset:36; size:4;
- field:int cpu; offset:40; size:4;
+ field:char comm[16]; offset:8; size:16; signed:0;
+ field:pid_t pid; offset:24; size:4; signed:1;
+ field:int prio; offset:28; size:4; signed:1;
+ field:int target_cpu; offset:32; size:4; signed:1;

- print fmt: "task %s:%d [%d] success=%d [%03d]", REC->comm, REC->pid,
- REC->prio, REC->success, REC->cpu
+ print fmt: "comm=%s pid=%d prio=%d target_cpu=%03d", REC->comm, REC->pid,
+ REC->prio, REC->target_cpu

-This event contains 10 fields, the first 5 common and the remaining 5
+This event contains 8 fields, the first 4 common and the remaining 4
event-specific. All the fields for this event are numeric, except for
'comm' which is a string, a distinction important for event filtering.

--
2.34.1



2024-04-10 20:21:09

by Steven Rostedt

[permalink] [raw]
Subject: Re: [PATCH] Documentation: tracing: update format of sched_wakeup in example

On Thu, 14 Mar 2024 15:41:36 +0100
Ali Zahraee <[email protected]> wrote:

> The format of the sched_wakeup event is used as an example in the
> documentation. But the given format is obsolete. This patch updates the
> format in the example to match the current format of this event.
>
> Signed-off-by: Ali Zahraee <[email protected]>
> ---
> Documentation/trace/events.rst | 25 +++++++++++++------------
> 1 file changed, 13 insertions(+), 12 deletions(-)
>
> diff --git a/Documentation/trace/events.rst b/Documentation/trace/events.rst
> index 759907c20e75..65fe205c95e6 100644
> --- a/Documentation/trace/events.rst
> +++ b/Documentation/trace/events.rst
> @@ -129,24 +129,25 @@ event::
> # cat /sys/kernel/tracing/events/sched/sched_wakeup/format
>
> name: sched_wakeup
> - ID: 60
> + ID: 70

Really don't need to change that, as it's defined at compile time and may
be different. For example, I have:

system: sched
name: sched_wakeup
ID: 297


> format:
> field:unsigned short common_type; offset:0; size:2;
> + signed:0;

Don't line break the fields, as new lines are part of the format.


> field:unsigned char common_flags; offset:2; size:1;
> - field:unsigned char common_preempt_count; offset:3; size:1;
> - field:int common_pid; offset:4; size:4;
> - field:int common_tgid; offset:8; size:4;
> + signed:0;
> + field:unsigned char common_preempt_count; offset:3;
> + size:1; signed:0;

Again, the above needs to be on one line.

Thanks,

-- Steve

> + field:int common_pid; offset:4; size:4; signed:1;
>
> - field:char comm[TASK_COMM_LEN]; offset:12; size:16;
> - field:pid_t pid; offset:28; size:4;
> - field:int prio; offset:32; size:4;
> - field:int success; offset:36; size:4;
> - field:int cpu; offset:40; size:4;
> + field:char comm[16]; offset:8; size:16; signed:0;
> + field:pid_t pid; offset:24; size:4; signed:1;
> + field:int prio; offset:28; size:4; signed:1;
> + field:int target_cpu; offset:32; size:4; signed:1;
>
> - print fmt: "task %s:%d [%d] success=%d [%03d]", REC->comm, REC->pid,
> - REC->prio, REC->success, REC->cpu
> + print fmt: "comm=%s pid=%d prio=%d target_cpu=%03d", REC->comm, REC->pid,
> + REC->prio, REC->target_cpu
>
> -This event contains 10 fields, the first 5 common and the remaining 5
> +This event contains 8 fields, the first 4 common and the remaining 4
> event-specific. All the fields for this event are numeric, except for
> 'comm' which is a string, a distinction important for event filtering.
>