On 08/21/2013 11:23 PM, Peter Zijlstra wrote:
On Wed, Aug 21, 2013 at 11:09:44AM -0400, Steven Rostedt wrote:
From: Jiejing Zhang <jiejzh...@nvidia.com>
ftrace only report pid in task switch event, which is
actually thread ID in user space view, the comm of
the thread will be like "Thread-1", "Compiler", etc
in android system, it's useful if we can add tgid
information in ftrace event to find out the process
id, and the process id's comm will help us to figure
out the application, which was useful on data analysis
tools.
Meh.. are you telling me you really can't do that otherwise?
Adding this information makes the tracepoint slower for everybody else.
How about you enable trace_sched_process_fork() and track things that
way?
Thanks for the tip, I have tried fix this by avoid add tgid in ftrace,
actually the relationship between thread and process can be figure by
analysis these two command's output:
`ps aTH -F` and `ps a -F`
also with fork event, it can totally avoid add such a patch in kernel.
Thanks.
Also, last time I tried to change one of these stupid tracepoints
userspace broke.. Rostedt says people should be using libtraceevent but
I'm sceptical.
Change-Id: Ia99f58a56d691d770b3beb2f76de0351e6194a4a
That needs to die.
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