From: Petr Mladek <pmladek@suse.com>
To: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>,
linux-kernel@vger.kernel.org,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: Re: [PATCH v2] printk: defer_console_output: use atomic update
Date: Thu, 10 Feb 2022 16:47:39 +0100 [thread overview]
Message-ID: <YgUzm5POctivsjUg@alley> (raw)
In-Reply-To: <87bkzj3t77.fsf@jogness.linutronix.de>
On Mon 2022-02-07 10:52:20, John Ogness wrote:
> The per-cpu @printk_pending variable can be updated from
> sleepable contexts, such as:
>
> get_random_bytes()
> warn_unseeded_randomness()
> printk_deferred()
> defer_console_output()
>
> and can be updated from interrupt contexts, such as:
>
> handle_irq_event_percpu()
> __irq_wake_thread()
> wake_up_process()
> try_to_wake_up()
> select_task_rq()
> select_fallback_rq()
> printk_deferred()
> defer_console_output()
>
> and can be updated from NMI contexts, such as:
>
> vprintk()
> if (in_nmi()) defer_console_output()
>
> Therefore this_cpu_or(), the atomic variant of __this_cpu_or(),
> should be used to update the variable.
>
> Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
> Signed-off-by: John Ogness <john.ogness@linutronix.de>
Makes sense.
The patch has been committed into printk/linux.git, branch for-5.18.
Best Regards,
Petr
next prev parent reply other threads:[~2022-02-10 15:47 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-03 11:29 [PATCH] printk: defer_console_output: do not assume interrupts disabled John Ogness
2022-02-03 11:33 ` Sebastian Andrzej Siewior
2022-02-04 7:04 ` Sergey Senozhatsky
2022-02-07 9:46 ` [PATCH v2] printk: defer_console_output: use atomic update John Ogness
2022-02-10 15:47 ` Petr Mladek [this message]
2022-02-11 11:22 ` John Ogness
2022-02-11 11:23 ` [PATCH v3] printk: use atomic updates for klogd work John Ogness
2022-02-14 5:35 ` Sergey Senozhatsky
2022-02-15 15:26 ` Petr Mladek
2022-02-14 5:32 ` [PATCH v2] printk: defer_console_output: use atomic update Sergey Senozhatsky
2022-02-14 5:35 ` Sergey Senozhatsky
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=YgUzm5POctivsjUg@alley \
--to=pmladek@suse.com \
--cc=bigeasy@linutronix.de \
--cc=john.ogness@linutronix.de \
--cc=linux-kernel@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=senozhatsky@chromium.org \
/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.