From: Steven Rostedt <rostedt@goodmis.org>
To: Menglong Dong <menglong8.dong@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
oe-lkp@lists.linux.dev, kernel test robot <oliver.sang@intel.com>,
lkp@intel.com, Menglong Dong <dongml2@chinatelecom.cn>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [linux-next:master] [tracing] dfe0d675df: WARNING:suspicious_RCU_usage
Date: Thu, 28 Aug 2025 10:34:33 -0400 [thread overview]
Message-ID: <20250828103433.1498f8a7@gandalf.local.home> (raw)
In-Reply-To: <CADxym3aHUDGahE1S2LzaDZA4vZP637txcMzQR3_r1U00GikEUA@mail.gmail.com>
On Thu, 28 Aug 2025 17:09:35 +0800
Menglong Dong <menglong8.dong@gmail.com> wrote:
> > [ 354.955971][ T4652] dump_stack_lvl+0x7c/0x90
> > [ 354.955978][ T4652] lockdep_rcu_suspicious+0x14f/0x1c0
> > [ 354.955987][ T4652] __rhashtable_lookup+0x1e0/0x260
>
> rcu_read_lock() is not needed in fprobe_entry, but
> rcu_dereference_check() is used in rhltable_lookup(), which
> causes this warning.
Why is rcu_read_lock() not needed in fprobe_entry()?
-- Steve
>
> Adding rcu_read_lock() here is able to suppress this warning.
> Maybe we need only rcu_lock_acquire(&rcu_lock_map) here,
> but it's not a common usage. What do you think, Masami?
next prev parent reply other threads:[~2025-08-28 14:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-28 8:43 [linux-next:master] [tracing] dfe0d675df: WARNING:suspicious_RCU_usage kernel test robot
2025-08-28 9:09 ` Menglong Dong
2025-08-28 14:34 ` Steven Rostedt [this message]
2025-08-29 0:47 ` Menglong Dong
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