From: Breno Leitao <leitao@debian.org>
To: Song Liu <song@kernel.org>
Cc: rcu@vger.kernel.org, paulmck@kernel.org,
linux-kernel@vger.kernel.org, kernel-team@meta.com,
rostedt@goodmis.org, david.dai@linux.dev
Subject: Re: [PATCH] rcu-tasks: Use pr_debug() for callback contend/collapse messages
Date: Thu, 12 Nov 2026 01:39:08 -0800 [thread overview]
Message-ID: <avWJMVvAuUEdjmuu@gmail.com> (raw)
In-Reply-To: <20261111053551.3367903-1-song@kernel.org>
On Tue, Nov 10, 2026 at 09:35:51PM -0800, Song Liu wrote:
> Commit 5de907d24919 ("rcu-tasks: Disable callback contend/collapse
> messages by default") added the rcupdate.rcu_task_collapse_debug module
> parameter to gate the three pr_info() messages that report RCU Tasks
> switching between CPU-0 and per-CPU callback queuing.
>
> The kernel already has a mechanism for debug-only messages that are off
> by default: pr_debug(). Use pr_debug() for these messages, and remove
> the rcu_task_collapse_debug module parameter, its documentation, and
> its boot-time announcement.
>
> The messages stay off by default. On CONFIG_DYNAMIC_DEBUG=y kernels,
> they can be enabled at boot with:
>
> dyndbg="file kernel/rcu/tasks.h +p"
>
> or at runtime with:
>
> echo 'file kernel/rcu/tasks.h +p' > /proc/dynamic_debug/control
>
> Assisted-by: Claude:claude-opus-5
> Signed-off-by: Song Liu <song@kernel.org>
Tested-by: Breno Leitao <leitao@debian.org>
prev parent reply other threads:[~2026-11-12 9:39 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-11 5:35 [PATCH] rcu-tasks: Use pr_debug() for callback contend/collapse messages Song Liu
2026-11-11 15:54 ` Joel Fernandes
2026-11-11 17:32 ` Song Liu
2026-11-11 18:22 ` Joel Fernandes
2026-11-11 18:52 ` Paul E. McKenney
2026-11-11 18:51 ` Paul E. McKenney
2026-11-12 9:39 ` Breno Leitao [this message]
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