diff options
| author | Tomas Glozar <tglozar@redhat.com> | 2025-10-10 10:33:37 +0200 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2025-11-05 11:19:20 -0700 |
| commit | b9f6a40dc3f03f1d688faad7bf9b7f78c366d0dd (patch) | |
| tree | c624ea338e999735ad849da26d60304b8a4e8062 /Documentation/trace | |
| parent | 122a552b5b1c1a33fa14e9d2d7d6a92a553a9c3e (diff) | |
Documentation/trace: Specify exact priority for timerlat
The timerlat tracer documentation mentions that threads are created with
real-time priority, but does not mention which priority and scheduling
class is used.
Add the information so that users do not have to look it up in
trace_osnoise.c.
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20251010083338.478961-9-tglozar@redhat.com>
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/timerlat-tracer.rst | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/Documentation/trace/timerlat-tracer.rst b/Documentation/trace/timerlat-tracer.rst index 53a56823e903..68d429d454a5 100644 --- a/Documentation/trace/timerlat-tracer.rst +++ b/Documentation/trace/timerlat-tracer.rst @@ -43,12 +43,12 @@ It is possible to follow the trace by reading the trace file:: <...>-868 [001] .... 54.030347: #2 context thread timer_latency 4351 ns -The tracer creates a per-cpu kernel thread with real-time priority that -prints two lines at every activation. The first is the *timer latency* -observed at the *hardirq* context before the activation of the thread. -The second is the *timer latency* observed by the thread. The ACTIVATION -ID field serves to relate the *irq* execution to its respective *thread* -execution. +The tracer creates a per-cpu kernel thread with real-time priority +SCHED_FIFO:95 that prints two lines at every activation. The first is +the *timer latency* observed at the *hardirq* context before the activation +of the thread. The second is the *timer latency* observed by the thread. +The ACTIVATION ID field serves to relate the *irq* execution to its +respective *thread* execution. The *irq*/*thread* splitting is important to clarify in which context the unexpected high value is coming from. The *irq* context can be |