From: Sebastian Sewior <bigeasy@linutronix.de>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Peter Ziljstra <peterz@infradead.org>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Andrii Nakryiko <andrii@kernel.org>, bpf <bpf@vger.kernel.org>,
Jiri Olsa <jolsa@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: Re: uprobe splat in PREEMP_RT
Date: Wed, 2 Apr 2025 14:24:47 +0200 [thread overview]
Message-ID: <20250402122447.B3XIrQnG@linutronix.de> (raw)
In-Reply-To: <20250402121850.GI22091@redhat.com>
On 2025-04-02 14:18:51 [+0200], Oleg Nesterov wrote:
> On 04/02, Sebastian Sewior wrote:
I need to tell mutt to replace my name in case it is misspelled.
> > The preempted ri_timer() could stall a read_seqcount_begin().
>
> Again, nobody use read_seqcount_begin(utask->ri_seqcount).
>
> free_ret_instance() uses raw_seqcount_try_begin(utask->ri_seqcount),
> which, since ri_seqcount is seqcount_t, is just smp_load_acquire().
> This can't stall.
Yes. This would work for here just to skip the check because of all
details that are hard to express. Therefore I suggested to use
raw_write_seqcount_begin() instead of write_seqcount_begin() in
20250402122158.j_8VoHQ-@linutronix.de. Would that work?
> Oleg.
Sebastian
next prev parent reply other threads:[~2025-04-02 12:24 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-01 21:04 uprobe splat in PREEMP_RT Alexei Starovoitov
2025-04-01 21:22 ` Steven Rostedt
2025-04-01 22:01 ` Andrii Nakryiko
2025-04-02 10:33 ` Oleg Nesterov
2025-04-02 10:57 ` Sebastian Sewior
2025-04-02 11:23 ` Oleg Nesterov
2025-04-02 12:13 ` Sebastian Sewior
2025-04-02 12:18 ` Oleg Nesterov
2025-04-02 12:24 ` Sebastian Sewior [this message]
2025-04-02 14:12 ` Oleg Nesterov
2025-04-03 7:37 ` Sebastian Sewior
2025-04-03 12:27 ` Oleg Nesterov
2025-04-03 16:04 ` Andrii Nakryiko
2025-04-02 16:15 ` Andrii Nakryiko
2025-04-02 16:57 ` Oleg Nesterov
2025-04-02 12:21 ` Sebastian Sewior
2025-04-02 9:10 ` Oleg Nesterov
2025-04-02 10:54 ` Sebastian Sewior
2025-04-02 11:20 ` Oleg Nesterov
2025-04-02 11:31 ` Oleg Nesterov
2025-04-02 12:06 ` Sebastian Sewior
2025-04-02 12:12 ` Oleg Nesterov
2025-04-02 12:16 ` Sebastian Sewior
2025-04-02 13:56 ` Oleg Nesterov
2025-04-02 14:23 ` Oleg Nesterov
2025-04-03 9:08 ` Sebastian Sewior
2025-04-03 12:11 ` Oleg Nesterov
2025-04-03 12:43 ` Oleg Nesterov
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