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Date: Mon, 04 May 2026 14:59:13 -1000
Message-ID: <8f3d856b5b2a9dc6c84b480d934007ac@kernel.org>
From: Tejun Heo <tj@kernel.org>
To: Cheng-Yang Chou <yphbchou0911@gmail.com>
Cc: sched-ext@lists.linux.dev,
 David Vernet <void@manifault.com>,
 Andrea Righi <arighi@nvidia.com>,
 Changwoo Min <changwoo@igalia.com>,
 "Paul E. McKenney" <paulmck@kernel.org>,
 rcu@vger.kernel.org,
 Ching-Chun Huang <jserv@ccns.ncku.edu.tw>,
 Chia-Ping Tsai <chia7712@gmail.com>
Subject: Re: [PATCH v2 2/2] sched_ext: Fix exit_cpu accuracy for lockup paths
In-Reply-To: <20260504161543.674488-3-yphbchou0911@gmail.com>
References: <20260504161543.674488-1-yphbchou0911@gmail.com>
 <20260504161543.674488-3-yphbchou0911@gmail.com>
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Hello,

> -		panic_on_rcu_stall();
> +		panic_on_rcu_stall(raw_smp_processor_id());

This one in synchronize_rcu_expedited_wait() - is raw_smp_processor_id()
the right CPU here? The wait runs in the grace-period worker context,
so the current CPU is the waiter, not a stuck one. The stuck CPUs are
the ones in rnp->expmask that synchronize_rcu_expedited_stall() just
iterated over.

Thanks.

--
tejun