From: John Ogness <john.ogness@linutronix.de>
To: Petr Mladek <pmladek@suse.com>
Cc: Marcos Paulo de Souza <mpdesouza@suse.com>,
Steven Rostedt <rostedt@goodmis.org>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
Jason Wessel <jason.wessel@windriver.com>,
Daniel Thompson <danielt@kernel.org>,
Douglas Anderson <dianders@chromium.org>,
Richard Weinberger <richard@nod.at>,
Anton Ivanov <anton.ivanov@cambridgegreys.com>,
Johannes Berg <johannes@sipsolutions.net>,
linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
kgdb-bugreport@lists.sourceforge.net,
linux-um@lists.infradead.org
Subject: Re: [PATCH 2/7] printk: Use consoles_suspended flag when suspending/resuming all consoles
Date: Tue, 24 Jun 2025 13:10:25 +0206 [thread overview]
Message-ID: <84wm919z9i.fsf@jogness.linutronix.de> (raw)
In-Reply-To: <aFpkQHwNCslbKSP6@pathway.suse.cz>
On 2025-06-24, Petr Mladek <pmladek@suse.com> wrote:
>> > Variant C:
>> > ==========
>> >
>> > Remove even @flags parameter from console_is_usable() and read both
>> > values there directly.
>> >
>> > Many callers read @flags only because they call console_is_usable().
>> > The change would simplify the code.
>> >
>> > But there are few exceptions:
>> >
>> > 2. Another exception is __pr_flush() where console_is_usable() is
>> > called twice with @use_atomic set "true" and "false".
>> >
>> > We would want to read "con->flags" only once here. A solution
>> > would be to add a parameter to check both con->write_atomic
>> > and con->write_thread in a single call.
>>
>> Or it could become a bitmask of printing types to check:
>>
>> #define ATOMIC_PRINTING 0x1
>> #define NONATOMIC_PRINTING 0x2
>>
>> and then __pr_flush() looks like:
>>
>> if (!console_is_usable(c, flags, ATOMIC_PRINTING|NONATOMIC_PRINTING)
>
> I like this. It will help even in all other cases when one mode is needed.
> I mean that, for example:
>
> console_is_usable(c, flags, ATOMIC_PRINTING)
>
> is more self-explaining than
>
> console_is_usable(c, flags, true)
After I wrote that suggestion, I decided that the naming is not
good. There is always confusion about what "atomic printing" means. For
that reason the parameter was changed to "use_atomic". Basically we are
specifying which callback to use and not the purpose. It is a bit tricky
because legacy consoles do not have an atomic callback, i.e. the
parameter only has meaning for nbcon consoles.
Perhaps these macros would be more suitable:
#define NBCON_USE_ATOMIC 0x1
#define NBCON_USE_THREAD 0x2
or
#define NBCON_USE_WRITE_ATOMIC 0x1
#define NBCON_USE_WRITE_THREAD 0x2
or
#define NBCON_ATOMIC_CB 0x1
#define NBCON_THREAD_CB 0x2
or
#define NBCON_ATOMIC_FUNC 0x1
#define NBCON_THREAD_FUNC 0x2
Hopefully that gives Petr enough ideas that he can come up with good
naming. ;-)
John
next prev parent reply other threads:[~2025-06-24 11:49 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-07 2:53 [PATCH 0/7] printk cleanup - part 2 Marcos Paulo de Souza
2025-06-07 2:53 ` [PATCH 1/7] printk: Make console_{suspend,resume} handle CON_SUSPENDED Marcos Paulo de Souza
2025-06-12 11:46 ` Petr Mladek
2025-06-23 18:45 ` Marcos Paulo de Souza
2025-06-07 2:53 ` [PATCH 2/7] printk: Use consoles_suspended flag when suspending/resuming all consoles Marcos Paulo de Souza
2025-06-13 15:20 ` Petr Mladek
2025-06-20 14:43 ` John Ogness
2025-06-24 8:40 ` Petr Mladek
2025-06-24 11:04 ` John Ogness [this message]
2025-06-25 8:48 ` Petr Mladek
2025-06-23 18:53 ` Marcos Paulo de Souza
2025-06-07 2:53 ` [PATCH 3/7] drivers: tty: Check CON_SUSPENDED instead of CON_ENABLED Marcos Paulo de Souza
2025-06-12 11:48 ` Petr Mladek
2025-06-07 2:53 ` [PATCH 4/7] drivers: serial: kgdboc: " Marcos Paulo de Souza
2025-06-09 20:13 ` Doug Anderson
2025-06-10 20:03 ` Marcos Paulo de Souza
2025-06-10 23:18 ` Doug Anderson
2025-06-12 13:57 ` Petr Mladek
2025-06-12 23:16 ` Doug Anderson
2025-06-13 10:52 ` Petr Mladek
2025-06-13 16:44 ` Doug Anderson
2025-06-07 2:53 ` [PATCH 5/7] arch: um: kmsg_dump: Don't check for CON_ENABLED Marcos Paulo de Souza
2025-06-16 13:33 ` Petr Mladek
2025-06-20 15:45 ` John Ogness
2025-06-07 2:53 ` [PATCH 6/7] debug: kgd_io: " Marcos Paulo de Souza
2025-06-16 13:56 ` Petr Mladek
2025-06-30 0:31 ` Marcos Paulo de Souza
2025-06-07 2:53 ` [PATCH 7/7] printk: Don't check for CON_ENABLED on console_unblank Marcos Paulo de Souza
2025-06-16 14:02 ` Petr Mladek
2025-06-17 9:32 ` Geert Uytterhoeven
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=84wm919z9i.fsf@jogness.linutronix.de \
--to=john.ogness@linutronix.de \
--cc=anton.ivanov@cambridgegreys.com \
--cc=danielt@kernel.org \
--cc=dianders@chromium.org \
--cc=gregkh@linuxfoundation.org \
--cc=jason.wessel@windriver.com \
--cc=jirislaby@kernel.org \
--cc=johannes@sipsolutions.net \
--cc=kgdb-bugreport@lists.sourceforge.net \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
--cc=linux-um@lists.infradead.org \
--cc=mpdesouza@suse.com \
--cc=pmladek@suse.com \
--cc=richard@nod.at \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).