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SubjectRe: [PATCH v0 13/71] perf tools: Add machine__get_thread_pid()
On 12/11/13, 2:18 PM, Andi Kleen wrote:
> David Ahern <> writes:
>> Are you looking up the current or next task? If the former why not use
>> sample->pid rather than parsing the sched_switch tracepoint?
> The itrace stream doesn't have a pid field, and it needs the exact
> time stamp of the switch. There may not actually be any samples
> before decoding.
> -Andi

What I meant is this:

perf record -e sched:sched_switch -a -- sleep 1 | perf script -f

qemu-system-x86 8688/8692 sched:sched_switch:
prev_comm=qemu-system-x86 prev_pid=8692 prev_prio=120 prev_state=S ==>
next_comm=swapper/15 next_pid=0 next_prio=120

8688/8692 are the pid and tid of the running task. If you are monitoring
sched_switch events and looking at running task -- the one getting
scheduled out -- you don't need to parse the tracepoint. But, if you
want to know next task then you do need to parse it. I was wondering
which task is getting looked up.


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