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From:   "Zhuo, Qiuxu" <qiuxu.zhuo@intel.com>
To:     Steven Rostedt <rostedt@goodmis.org>,
        Uladzislau Rezki <urezki@gmail.com>
CC:     "Paul E . McKenney" <paulmck@kernel.org>,
        RCU <rcu@vger.kernel.org>,
        "quic_neeraju@quicinc.com" <quic_neeraju@quicinc.com>,
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        Joel Fernandes <joel@joelfernandes.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>,
        Frederic Weisbecker <frederic@kernel.org>
Subject: RE: [PATCH 1/1] Reduce synchronize_rcu() waiting time
Thread-Topic: [PATCH 1/1] Reduce synchronize_rcu() waiting time
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Date:   Tue, 28 Mar 2023 01:28:01 +0000
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> From: Steven Rostedt <rostedt@goodmis.org>
> Sent: Tuesday, March 28, 2023 5:51 AM
> [...]
> Subject: Re: [PATCH 1/1] Reduce synchronize_rcu() waiting time
>=20
> On Mon, 27 Mar 2023 17:48:44 -0400
> Steven Rostedt <rostedt@goodmis.org> wrote:
>=20
> > struct my_info {
> > 	/* store state info here */
> > };
> >
> > int main(...) {
> > 	struct tracecmd_input *handle;
> > 	struct my_info info;
> > 	char *file =3D argv[1];
> >
> > 	handle =3D tracecmd_open(file);
> >
> > 	tracecmd_follow_event(handle, "rcu", "rcu_batch_start",
> > 			batch_start, &info);
> >
> > 	tracecmd_follow_event(handle, "rcu", "rcu_batch_end",
> > 			batch_end, &info);
> >
> > 	tracecmd_follow_event(handle, "rcu", "rcu_invoke_callback",
> > 			invoke_callback, &info);
> >
> > 	tracecmd_iterate_events(handle, NULL, 0, NULL, NULL);
> >
> > 	tracecmd_close(handle);
> > }
>=20
> BTW, none of this code was actually tested, so I may have some syntax
> errors. I just did this straight from memory, as it's so easy ;-)

Thank you Steven for sharing the libtracecmd-based and libtraceevent-based=
=20
methods for trace parsing. Good to know this. This should simplify the code=
=20
to parse trace logs. Pretty useful for me/us ;-)

- Qiuxu

>=20
> -- Steve