Messages in this thread | | | Date | Fri, 9 Jan 2015 11:25:05 -0500 | From | Steven Rostedt <> | Subject | Re: Preemptionirqsoff latency issue |
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On Fri, 9 Jan 2015 20:19:51 +0530 Vaibhav Shinde <v.bhav.shinde@gmail.com> wrote:
> Hi Peter, > > Thanks for you reply. > > I am interested in scheduling latency, and using ftrace I see for my > application suffering from it, that's why I am digging in preemption/irq > disable time which might cause the latency. > > My app runs on cpu0, while other cpus looks idle; as per my understanding > from your comment owner of the mutex is on the cpu other than cpu0, and > which is causing wait spin on cpu0. > Can this be the reason why latency is caused ? > If so, then I think I need to take care of the mutex lock which is called > from my code. >
If you download and install the latest trace-cmd, you may be able to get more information with its new command "profile".
# trace-cmd profile -o file workload
Then look at the output in file.
To limit the running to tracing only the workload:
# trace-cmd profile -o file -F -c workload
You'll need to use the latest that's in my repo. Use the master branch, as it has all the above features.
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git
-- Steve
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