diff options
Diffstat (limited to 'Documentation/trace/ftrace.rst')
| -rw-r--r-- | Documentation/trace/ftrace.rst | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index 4073ca48af4a..af66a05e18cc 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -810,6 +810,12 @@ Here is the list of current tracers that may be configured. to draw a graph of function calls similar to C code source. + Note that the function graph calculates the timings of when the + function starts and returns internally and for each instance. If + there are two instances that run function graph tracer and traces + the same functions, the length of the timings may be slightly off as + each read the timestamp separately and not at the same time. + "blk" The block tracer. The tracer used by the blktrace user @@ -1031,14 +1037,15 @@ explains which is which. CPU#: The CPU which the process was running on. irqs-off: 'd' interrupts are disabled. '.' otherwise. - .. caution:: If the architecture does not support a way to - read the irq flags variable, an 'X' will always - be printed here. need-resched: + - 'B' all, TIF_NEED_RESCHED, PREEMPT_NEED_RESCHED and TIF_RESCHED_LAZY is set, - 'N' both TIF_NEED_RESCHED and PREEMPT_NEED_RESCHED is set, - 'n' only TIF_NEED_RESCHED is set, - 'p' only PREEMPT_NEED_RESCHED is set, + - 'L' both PREEMPT_NEED_RESCHED and TIF_RESCHED_LAZY is set, + - 'b' both TIF_NEED_RESCHED and TIF_RESCHED_LAZY is set, + - 'l' only TIF_RESCHED_LAZY is set - '.' otherwise. hardirq/softirq: @@ -1198,6 +1205,19 @@ Here are the available options: default instance. The only way the top level instance has this flag cleared, is by it being set in another instance. + copy_trace_marker + If there are applications that hard code writing into the top level + trace_marker file (/sys/kernel/tracing/trace_marker or trace_marker_raw), + and the tooling would like it to go into an instance, this option can + be used. Create an instance and set this option, and then all writes + into the top level trace_marker file will also be redirected into this + instance. + + Note, by default this option is set for the top level instance. If it + is disabled, then writes to the trace_marker or trace_marker_raw files + will not be written into the top level file. If no instance has this + option set, then a write will error with the errno of ENODEV. + annotate It is sometimes confusing when the CPU buffers are full and one CPU buffer had a lot of events recently, thus @@ -3070,7 +3090,7 @@ Notice that we lost the sys_nanosleep. # cat set_ftrace_filter hrtimer_run_queues hrtimer_run_pending - hrtimer_init + hrtimer_setup hrtimer_cancel hrtimer_try_to_cancel hrtimer_forward @@ -3108,7 +3128,7 @@ Again, now we want to append. # cat set_ftrace_filter hrtimer_run_queues hrtimer_run_pending - hrtimer_init + hrtimer_setup hrtimer_cancel hrtimer_try_to_cancel hrtimer_forward |