From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Cc: Mat Martineau <martineau@kernel.org>,
Geliang Tang <geliang@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>, Florian Westphal <fw@strlen.de>,
netdev@vger.kernel.org, mptcp@lists.linux.dev,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
stable@vger.kernel.org, Clark Williams <clrkwllms@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Hannes Reinecke <hare@kernel.org>,
linux-rt-devel@lists.linux.dev
Subject: Re: [PATCH net 09/10] mptcp: pm: avoid sleeping while holding rcu_read_lock
Date: Mon, 1 Jun 2026 08:58:13 +0200 [thread overview]
Message-ID: <20260601065813.Z8V8Tb6d@linutronix.de> (raw)
In-Reply-To: <20260601-net-mptcp-misc-fixes-7-1-rc7-v1-9-a5ae7791754b@kernel.org>
On 2026-06-01 13:10:05 [+1000], Matthieu Baerts (NGI0) wrote:
> sk_stop_timer_sync() calls del_timer_sync(), which spin-waits for the
There is no del_timer_sync()
> timer callback to complete on non-RT kernels. But on PREEMPT_RT, it can
> sleep. Sleeping inside an RCU read-side critical section might trigger a
> lockdep splat.
It can not sleep. timer_delete_sync() does not sleep. It can block on
spinlock_t and schedule but this is okay within a RCU read section.
Do you have a report for this?
Sebastian
next prev parent reply other threads:[~2026-06-01 6:58 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-01 3:09 [PATCH net 00/10] mptcp: misc fixes for v7.1-rc7 Matthieu Baerts (NGI0)
2026-06-01 3:09 ` [PATCH net 01/10] mptcp: fix missing wakeups in edge scenarios Matthieu Baerts (NGI0)
2026-06-01 3:09 ` [PATCH net 02/10] mptcp: fix retransmission loop when csum is enabled Matthieu Baerts (NGI0)
2026-06-01 3:09 ` [PATCH net 03/10] mptcp: close TOCTOU race while computing rcv_wnd Matthieu Baerts (NGI0)
2026-06-01 3:10 ` [PATCH net 04/10] mptcp: allow subflow rcv wnd to shrink Matthieu Baerts (NGI0)
2026-06-01 3:10 ` [PATCH net 05/10] mptcp: pm: fix extra_subflows underflow on userspace PM subflow creation Matthieu Baerts (NGI0)
2026-06-01 3:10 ` [PATCH net 06/10] selftests: mptcp: add test for extra_subflows underflow on userspace PM Matthieu Baerts (NGI0)
2026-06-01 3:10 ` [PATCH net 07/10] mptcp: sockopt: check timestamping ret value Matthieu Baerts (NGI0)
2026-06-01 3:10 ` [PATCH net 08/10] mptcp: sockopt: set sockopt on all subflows Matthieu Baerts (NGI0)
2026-06-01 3:10 ` [PATCH net 09/10] mptcp: pm: avoid sleeping while holding rcu_read_lock Matthieu Baerts (NGI0)
2026-06-01 6:58 ` Sebastian Andrzej Siewior [this message]
2026-06-01 7:27 ` Matthieu Baerts
2026-06-01 3:10 ` [PATCH net 10/10] mptcp: check desc->count in read_sock Matthieu Baerts (NGI0)
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