Re: [patch V2 13/17] timers: Split [try_to_]del_timer[_sync]() to prepare for shutdown mode

From: Jacob Keller <jacob.e.keller@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	LKML <linux-kernel@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Anna-Maria Behnsen <anna-maria@linutronix.de>,
	"Peter Zijlstra" <peterz@infradead.org>,
	Stephen Boyd <sboyd@kernel.org>,
	"Guenter Roeck" <linux@roeck-us.net>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Julia Lawall" <Julia.Lawall@inria.fr>,
	Arnd Bergmann <arnd@arndb.de>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Marc Zyngier <maz@kernel.org>,
	Marcel Holtmann <marcel@holtmann.org>,
	Johan Hedberg <johan.hedberg@gmail.com>,
	"Luiz Augusto von Dentz" <luiz.dentz@gmail.com>,
	<linux-bluetooth@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	"Jakub Kicinski" <kuba@kernel.org>,
	Paolo Abeni <pabeni@redhat.com>, <netdev@vger.kernel.org>
Subject: Re: [patch V2 13/17] timers: Split [try_to_]del_timer[_sync]() to prepare for shutdown mode
Date: Tue, 22 Nov 2022 15:04:41 -0800	[thread overview]
Message-ID: <74922e6d-73d5-62cc-3679-96ea447a1cb4@intel.com> (raw)
In-Reply-To: <20221122173648.849454220@linutronix.de>

On 11/22/2022 9:45 AM, Thomas Gleixner wrote:
> +/**
> + * try_to_del_timer_sync - Try to deactivate a timer
> + * @timer:	Timer to deactivate
> + *
> + * This function tries to deactivate a timer. On success the timer is not
> + * queued and the timer callback function is not running on any CPU.
> + *
> + * This function does not guarantee that the timer cannot be rearmed right
> + * after dropping the base lock. That needs to be prevented by the calling
> + * code if necessary.
> + *
> + * Return:
> + * * %0  - The timer was not pending
> + * * %1  - The timer was pending and deactivated
> + * * %-1 - The timer callback function is running on a different CPU
> + */
> +int try_to_del_timer_sync(struct timer_list *timer)
> +{
> +	return __try_to_del_timer_sync(timer);
> +}
>   EXPORT_SYMBOL(try_to_del_timer_sync);
>   

Its a bit odd to me that some patches refactor and replace functions 
with new variants all under timer_* namespace, but then we've left some 
of them available without that.

Any reasoning behind this? I guess "try_*" is pretty clear and unlikely 
to get stolen by other code..?

Thanks,
Jake