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From:   Joel Fernandes <joel@joelfernandes.org>
Date:   Mon, 10 Jul 2023 15:55:16 -0400
Message-ID: <CAEXW_YR_t-x-eYKLFmruOLqZv91oi=AJKEEeuqYosejjdscn1g@mail.gmail.com>
Subject: Re: [PATCH 2/2] rcu: Don't dump the stalled CPU on where RCU GP
 kthread last ran twice
To:     paulmck@kernel.org
Cc:     Zhen Lei <thunder.leizhen@huawei.com>,
        Frederic Weisbecker <frederic@kernel.org>,
        Neeraj Upadhyay <quic_neeraju@quicinc.com>,
        Josh Triplett <josh@joshtriplett.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Lai Jiangshan <jiangshanlai@gmail.com>,
        Zqiang <qiang.zhang1211@gmail.com>, rcu@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Mon, Jul 10, 2023 at 3:06=E2=80=AFPM Paul E. McKenney <paulmck@kernel.or=
g> wrote:
>
> On Wed, Jul 05, 2023 at 03:30:20PM +0800, Zhen Lei wrote:
> > The stacks of all stalled CPUs will be dumped. If the CPU on where RCU =
GP
> > kthread last ran is stalled, its stack does not need to be dumped again=
.
> >
> > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
>
> This one looks good.  Please feel free to rebase it before 1/2 and repost=
.

Just a small comment:
I wondered if this would make it harder to identify which stack among
the various CPU stacks corresponds to the one the GP kthread is
running on. However, this line does print the CPU number of the
thread, so it is perhaps not an issue:

                pr_err("%s kthread starved for %ld jiffies! g%ld f%#x
%s(%d) ->state=3D%#x ->cpu=3D%d\n",

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>

Thanks.