linux-kernel - Re: [PATCH v5 1/5] ACPI / processor_idle: introduce ACPI_PROCESSOR

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Message-ID: <573448A0.5030003@arm.com>
Date:	Thu, 12 May 2016 10:10:56 +0100
From:	Sudeep Holla <sudeep.holla@....com>
To:	Len Brown <lenb@...nel.org>
Cc:	Sudeep Holla <sudeep.holla@....com>,
	linux acpi <linux-acpi@...r.kernel.org>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Vikas Sajjan <vikas.cha.sajjan@....com>,
	Sunil <sunil.vl@....com>,
	Prashanth Prakash <pprakash@...eaurora.org>,
	Ashwin Chaugule <ashwin.chaugule@...aro.org>,
	Al Stone <al.stone@...aro.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
	X86 ML <x86@...nel.org>, linux-ia64@...r.kernel.org
Subject: Re: [PATCH v5 1/5] ACPI / processor_idle: introduce
 ACPI_PROCESSOR_CSTATE

(I seem to have 2 emails, replying on the second)

On 11/05/16 19:28, Len Brown wrote:
> What is the functional goal/purpose of adding CONFIG_ACPI_PROCESSOR_CSTATE?
>

Avoid adding unnecessary dummy implementations of functions and
variables that will never be used on ARM64 and also looks ugly IMO. 
E.g.:	arch_safe_halt
	boot_option_idle_override
	IDLE_NOMWAIT
	acpi_unlazy_tlb
	acpi_processor_cstate_check
	disabled_by_idle_boot_param and more...

> If the answer is that it saves code space on an ARM build, how much
> space does it save?
>

NO, it doesn't even add a kB of code I believe, so that's definitely not
the reason. I am fine to retain if we can find a saner way to solve the
above issue.

-- 
Regards,
Sudeep