[for-linus][PATCH 0/2] tracing: Fixes for 6.13

Steven Rostedt posted 2 patches 11 months ago
kernel/trace/trace.c              |  1 +
kernel/trace/trace_irqsoff.c      | 14 ++++++++++++++
kernel/trace/trace_sched_wakeup.c | 14 ++++++++++++++
3 files changed, 29 insertions(+)
[for-linus][PATCH 0/2] tracing: Fixes for 6.13
Posted by Steven Rostedt 11 months ago
Tracing fixes for 6.13:

- Fix a regression in the irqsoff and wakeup latency tracing

  The function graph tracer infrastructure has become generic so that
  kretprobes and BPF can be based on it. As it use to only handle
  function graph tracing, it would always calculate the time the
  function entered so that it could then calculate the time it exits
  and give the length of time the function executed for. But this is
  not needed for the other users (kretprobes and BPF) and the reading
  the clock adds a non-negligible overhead, so the calculation was
  moved into the function graph tracer logic.

  But the irqsoff and wakeup latency tracers, when the "display-graph"
  option was set, would use the function graph tracer to calculate the
  times of functions during the latency. The movement of the calltime
  calculation made the value zero for these tracers, and the output
  no longer showed the length of time of each tracer, but instead the
  absolute timestamp of when the function returned (rettime - calltime
  where calltime is zero).

  Have the irqsoff and wakeup latency tracers also do the calltime
  calculation as the function graph tracer does.

- Update the tracing display to reflect the new preempt lazy model

  When the system is configured with preempt lazy, the output of the
  trace data would state "unknown" for the current preemption model.
  Because the lazy preemption model was just added, make it known
  to the tracing subsystem too.

  git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace/fixes

Head SHA1: 24e0e610400aa2c765ee87b1b3c1401732b20fc5


Shrikanth Hegde (1):
      tracing: Print lazy preemption model

Steven Rostedt (1):
      tracing: Fix irqsoff and wakeup latency tracers when using function graph

----
 kernel/trace/trace.c              |  1 +
 kernel/trace/trace_irqsoff.c      | 14 ++++++++++++++
 kernel/trace/trace_sched_wakeup.c | 14 ++++++++++++++
 3 files changed, 29 insertions(+)