From: John Kacur <jkacur@redhat.com>
To: Lars Segerlund <lars.segerlund@gmail.com>
Cc: linux-rt-users@vger.kernel.org
Subject: Re: tracefs .. idea
Date: Tue, 16 Oct 2012 13:04:13 +0200 (CEST) [thread overview]
Message-ID: <alpine.LFD.2.02.1210161301460.3137@tycho> (raw)
In-Reply-To: <CAF-VNaq+CpDLzLXVg2o2KAZ7fyQfhvxAs6wRWrgvHh3jJ9+2fQ@mail.gmail.com>
On Tue, 16 Oct 2012, Lars Segerlund wrote:
> I was thinking of tracking locks and above all interrupt disable
> through debugfs.
>
> Something along the lines of a buffer with the top offenders in it,
> and thus getting a list of the longest latency introducing sections.
> Or would it be 'better' to instrument with something like kprobes and
> have a utility for this functionality ?
>
> Any further idea of stuff to trace ? or has this already been done
> and I am unaware of it ?
>
> I basicly want a list of the sections in the kernel that disables
> preemption for the longest time.
Hi Lars - Have a look at ftrace, I think it does what you are looking for.
In the kernel source read, Documentation/trace/ftrace.txt
Look at "preemptoff" to see how to record the amount of time preemption is
disabled.
John
prev parent reply other threads:[~2012-10-16 11:02 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-16 10:44 tracefs .. idea Lars Segerlund
2012-10-16 11:04 ` John Kacur [this message]
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