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I'm using ftrace. There is task/pid field. What is the task? Is it process's thread id? If no, is it possible to get information about threads with same pid with ftrace? I used only function and function_graph.

Excentricitet
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1 Answers1

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The PID column in the trace buffer corresponds to a thread : It is the value of the field named pid of structure task_struct (defined in sched.h).

It is confusing for historical reasons but here pid is a unique identifier of a task (thread) : The basic entity scheduled by the kernel.

One can say it is matching a process only if this process has only one thread, because a process PID is equal to the unique id of its main thread.

Eric Marchand
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