From: John Ogness <john.ogness@linutronix.de>
To: Doug Anderson <dianders@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org,
Jason Wessel <jason.wessel@windriver.com>,
Daniel Thompson <daniel.thompson@linaro.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
kgdb-bugreport@lists.sourceforge.net,
linux-serial@vger.kernel.org
Subject: Re: [PATCH printk v5 37/40] tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()
Date: Thu, 17 Nov 2022 11:06:40 +0106 [thread overview]
Message-ID: <87pmdloq7r.fsf@jogness.linutronix.de> (raw)
In-Reply-To: <CAD=FV=WWZAAhw7rWjCvtqz6VGh-PzG_zMnugX_KkG7gZ+a9Qpw@mail.gmail.com>
On 2022-11-16, Doug Anderson <dianders@chromium.org> wrote:
> Seems OK to me, though I guess I would have moved console_lock() up
> too just because this isn't a case we need to optimize and then we can
> be extra certain that nobody else is messing with console structures
> while we're looking at them.
Actually this series is not about optimization. It is about reducing the
scope of console_lock and removing unnecessary use of it.
If tty_find_polling_driver() needs to be called under the console_lock,
then we need to document exactly why. I could not find any situations
where it is necessary.
Also keep in mind that in the long term we will be completely removing
the console_lock. It is a painful process of identifying and dismantling
its scope and replacing it with multiple clearly scoped locking
mechanisms.
> Reviewed-by: Douglas Anderson <dianders@chromium.org>
Thanks.
John
next prev parent reply other threads:[~2022-11-17 10:00 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-16 16:21 [PATCH printk v5 00/40] reduce console_lock scope John Ogness
2022-11-16 16:21 ` [PATCH printk v5 01/40] serial: kgdboc: Lock console list in probe function John Ogness
2022-11-16 16:21 ` [PATCH printk v5 02/40] printk: Convert console_drivers list to hlist John Ogness
2022-11-16 16:21 ` [PATCH printk v5 03/40] printk: Prepare for SRCU console list protection John Ogness
2022-12-01 18:22 ` Nathan Chancellor
2022-12-01 21:36 ` John Ogness
2022-12-01 21:56 ` Paul E. McKenney
2022-12-01 22:12 ` John Ogness
2022-12-02 0:21 ` Paul E. McKenney
2022-12-02 10:53 ` Petr Mladek
2022-11-16 16:21 ` [PATCH printk v5 04/40] printk: register_console: use "registered" for variable names John Ogness
2022-11-16 16:21 ` [PATCH printk v5 05/40] printk: move @seq initialization to helper John Ogness
2022-11-18 9:56 ` Petr Mladek
2022-11-16 16:21 ` [PATCH printk v5 06/40] printk: fix setting first seq for consoles John Ogness
2022-11-18 10:23 ` Petr Mladek
2022-11-18 10:52 ` John Ogness
2022-11-16 16:21 ` [PATCH printk v5 07/40] um: kmsg_dump: only dump when no output console available John Ogness
2022-11-16 16:21 ` [PATCH printk v5 08/40] tty: serial: kgdboc: document console_lock usage John Ogness
2022-11-16 16:21 ` [PATCH printk v5 09/40] tty: tty_io: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 10/40] proc: consoles: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 11/40] printk: introduce console_list_lock John Ogness
2022-11-21 11:10 ` [PATCH printk v6 " John Ogness
2022-11-21 13:36 ` Petr Mladek
2022-11-16 16:21 ` [PATCH printk v5 12/40] console: introduce wrappers to read/write console flags John Ogness
2022-11-16 16:21 ` [PATCH printk v5 13/40] um: kmsg_dumper: use srcu console list iterator John Ogness
2022-11-16 16:21 ` [PATCH printk v5 14/40] kdb: " John Ogness
2022-11-17 0:59 ` Doug Anderson
2022-11-16 16:21 ` [PATCH printk v5 15/40] printk: console_flush_all: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 16/40] printk: __pr_flush: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 17/40] printk: console_is_usable: use console_srcu_read_flags John Ogness
2022-11-16 16:21 ` [PATCH printk v5 18/40] printk: console_unblank: use srcu console list iterator John Ogness
2022-11-16 16:21 ` [PATCH printk v5 19/40] printk: console_flush_on_panic: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 20/40] printk: console_device: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 21/40] console: introduce console_is_registered() John Ogness
2022-11-16 16:21 ` [PATCH printk v5 22/40] serial_core: replace uart_console_enabled() with uart_console_registered() John Ogness
2022-11-16 16:21 ` [PATCH printk v5 23/40] tty: nfcon: use console_is_registered() John Ogness
2022-11-17 8:18 ` Geert Uytterhoeven
2022-11-16 16:21 ` [PATCH printk v5 24/40] efi: earlycon: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 25/40] tty: hvc: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 26/40] tty: serial: earlycon: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 27/40] tty: serial: pic32_uart: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 28/40] tty: serial: samsung_tty: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 29/40] tty: serial: xilinx_uartps: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 30/40] usb: early: xhci-dbc: " John Ogness
2022-11-16 16:21 ` [PATCH printk v5 31/40] netconsole: avoid CON_ENABLED misuse to track registration John Ogness
2022-11-16 16:21 ` [PATCH printk v5 32/40] printk, xen: fbfront: create/use safe function for forcing preferred John Ogness
2022-11-16 16:21 ` [PATCH printk v5 33/40] tty: tty_io: use console_list_lock for list synchronization John Ogness
2022-11-16 16:21 ` [PATCH printk v5 34/40] proc: consoles: use console_list_lock for list iteration John Ogness
2022-11-16 16:21 ` [PATCH printk v5 35/40] tty: serial: kgdboc: use srcu console list iterator John Ogness
2022-11-17 0:59 ` Doug Anderson
2022-11-17 9:32 ` John Ogness
2022-11-16 16:21 ` [PATCH printk v5 36/40] tty: serial: kgdboc: use console_list_lock for list traversal John Ogness
2022-11-17 0:59 ` Doug Anderson
2022-11-16 16:21 ` [PATCH printk v5 37/40] tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console() John Ogness
2022-11-17 0:59 ` Doug Anderson
2022-11-17 10:00 ` John Ogness [this message]
2022-11-16 16:21 ` [PATCH printk v5 38/40] tty: serial: kgdboc: use console_list_lock to trap exit John Ogness
2022-11-17 0:56 ` Doug Anderson
2022-11-17 11:08 ` John Ogness
2022-11-16 16:21 ` [PATCH printk v5 39/40] printk: relieve console_lock of list synchronization duties John Ogness
2022-11-18 11:07 ` Petr Mladek
2022-11-16 16:21 ` [PATCH printk v5 40/40] tty: serial: sh-sci: use setup() callback for early console John Ogness
2022-11-18 11:22 ` [PATCH printk v5 00/40] reduce console_lock scope Petr Mladek
2022-11-18 14:55 ` Petr Mladek
2022-11-22 16:43 ` Greg Kroah-Hartman
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