From: Steven Rostedt <rostedt@goodmis.org>
To: Zheng Yejian <zhengyejian@huaweicloud.com>
Cc: mhiramat@kernel.org, mathieu.desnoyers@efficios.com,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH] tracing: Mitigate possible softlockup in __tracing_open()
Date: Tue, 27 Aug 2024 07:52:41 -0400 [thread overview]
Message-ID: <20240827075241.5cd652ae@rorschach.local.home> (raw)
In-Reply-To: <d3c2ecfd-6590-dc17-4ea5-d80872d01016@huaweicloud.com>
On Tue, 27 Aug 2024 09:29:55 +0800
Zheng Yejian <zhengyejian@huaweicloud.com> wrote:
> > This is the wrong place to put this. If the problem is with
> > tracing_iter_reset(), then add it there.
> >
> > while (ring_buffer_iter_peek(buf_iter, &ts)) {
> > if (ts >= iter->array_buffer->time_start)
> > break;
> > entries++;
> > ring_buffer_iter_advance(buf_iter);
> > /* This could be a big loop */
> > cond_resched();
>
> Do resched check every event peek, I'm afraid there will
> be too many 're-schedule'.
cond_resched() as the name suggests only schedules conditionally if
NEED_RESCHED is set. This isn't a fast path (obviously, as it requires
a cond_resched).
-- Steve
next prev parent reply other threads:[~2024-08-27 11:52 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-24 3:03 [PATCH] tracing: Mitigate possible softlockup in __tracing_open() Zheng Yejian
2024-08-25 15:05 ` Masami Hiramatsu
2024-08-26 2:55 ` Zheng Yejian
2024-08-26 14:35 ` Steven Rostedt
2024-08-27 1:29 ` Zheng Yejian
2024-08-27 11:52 ` Steven Rostedt [this message]
2024-08-27 12:46 ` [PATCH v2] tracing: Avoid possible softlockup in tracing_iter_reset() Zheng Yejian
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