suse man page for utrace_barrier_pid

UTRACE_BARRIER_PID(9)						  utrace core API					     UTRACE_BARRIER_PID(9)

NAME
       utrace_barrier_pid - synchronize with simultaneous tracing callbacks

SYNOPSIS
       __must_check int utrace_barrier_pid(struct pid * pid, struct utrace_engine * engine);

ARGUMENTS
       pid
	   thread to affect

       engine
	   engine to affect (can be detached)

DESCRIPTION
       This is the same as utrace_barrier, but takes a struct pid pointer rather than a struct task_struct pointer. The caller must hold a ref on
       pid, but does not need to worry about the task staying valid. If it's been reaped so that pid points nowhere, then this call returns
       -ESRCH.

Kernel Hackers Manual 2.6.					     July 2010						     UTRACE_BARRIER_PID(9)