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Date:   Thu, 5 Sep 2019 10:13:10 +0200
From:   Ingo Molnar <mingo@kernel.org>
To:     Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Joel Fernandes <joel@joelfernandes.org>,
        Qais Yousef <qais.yousef@arm.com>,
        Valentin Schneider <valentin.schneider@arm.com>,
        Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
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        "H. Peter Anvin" <hpa@zytor.com>,
        Andy Lutomirski <luto@kernel.org>,
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        X86 ML <x86@kernel.org>
Subject: Re: [PATCH 2/2] sched/debug: add sched_update_nr_running tracepoint
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* Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:

> On Wed, Sep 4, 2019 at 10:47 AM Peter Zijlstra <peterz@infradead.org> wrote:
> >
> > On Wed, Sep 04, 2019 at 08:51:21AM -0700, Alexei Starovoitov wrote:
> > > Anything in tracing can be deleted.
> > > Tracing is about debugging and introspection.
> > > When underlying kernel code changes the introspection points change as well.
> >
> > Right; except when it breaks widely used tools; like say powertop. Been
> > there, done that.
> 
> powertop was a lesson learned, but it's not a relevant example anymore.
> There are more widely used tools today. Like bcc tools.
> And bpftrace is quickly gaining momentum and large user base.
> bcc tools did break already several times and people fixed them.

Are these tools using libtraceevents?

Thanks,

	Ingo