All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jonas Jelonek <jelonek.jonas@gmail.com>
To: Huacai Chen <chenhuacai@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	linux-mips@vger.kernel.org,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Clark Williams <clrkwllms@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Thomas Gleixner <tglx@kernel.org>,
	Jiayuan Chen <jiayuan.chen@linux.dev>,
	linux-rt-devel@lists.linux.dev, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH v2] MIPS: smp: report dying CPU to RCU in stop_this_cpu()
Date: Mon, 15 Jun 2026 09:40:45 +0200	[thread overview]
Message-ID: <9cd444b3-aeb0-46bb-a8a3-1526aa8f191a@gmail.com> (raw)
In-Reply-To: <CAAhV-H5psOJQey+frswdc5Q76UnhCkrHJ_jtqvxHsfmi-dskyw@mail.gmail.com>

On 15.06.26 09:30, Huacai Chen wrote:
>> [...]
>>
>>> However, synchronize_rcu() only gets called in the
>>> IS_ENABLED(CONFIG_PREEMPT_RT) case, so I think your configuration
>>> needs PREEMPT_RT, right?
>>>
>>> You said this is the default behavior, but PREEMPT_RT is not enabled by default.
>> The condition where this is added has two parts, see [1]. While PREEMPT_RT
>> isn't active for MIPS, arch_irq_work_has_interrupt gives false for MIPS (since
>> there is no implementation and it falls back to the generic one). This then
>> also calls synchronize_rcu.
> Sorry, this is my mistake, then what's your preemption model? There
> are too many config files for MIPS now.

I'm using PREEMPT_NONE, apparently default for all targets in OpenWrt.

> Huacai
>
>>> Huacai
>>>
>> Best,
>> Jonas
>>
>> [1] https://elixir.bootlin.com/linux/v7.1-rc7/source/kernel/irq_work.c#L291-L302

Best,
Jonas

      reply	other threads:[~2026-06-15  7:40 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-08  9:37 [PATCH v2] MIPS: smp: report dying CPU to RCU in stop_this_cpu() Jonas Jelonek
2026-06-10  6:05 ` Huacai Chen
2026-06-15  7:00   ` Jonas Jelonek
2026-06-15  7:09     ` Huacai Chen
2026-06-15  7:16       ` Jonas Jelonek
2026-06-15  7:30         ` Huacai Chen
2026-06-15  7:40           ` Jonas Jelonek [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=9cd444b3-aeb0-46bb-a8a3-1526aa8f191a@gmail.com \
    --to=jelonek.jonas@gmail.com \
    --cc=bigeasy@linutronix.de \
    --cc=chenhuacai@kernel.org \
    --cc=clrkwllms@kernel.org \
    --cc=jiayuan.chen@linux.dev \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mips@vger.kernel.org \
    --cc=linux-rt-devel@lists.linux.dev \
    --cc=rostedt@goodmis.org \
    --cc=stable@vger.kernel.org \
    --cc=tglx@kernel.org \
    --cc=tsbogend@alpha.franken.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.