linux-kernel - Re: [PATCH] x86/apic: Remove the extra judgement of skipped IO APIC setup

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Date:   Wed, 1 Mar 2017 17:31:55 +0800
From:   Dou Liyang <douly.fnst@...fujitsu.com>
To:     Ingo Molnar <mingo@...nel.org>
CC:     <tglx@...utronix.de>, <hpa@...or.com>, <bp@...en8.de>,
        <wanpeng.li@...mail.com>, <nicstange@...il.com>, <x86@...nel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86/apic: Remove the extra judgement of skipped IO APIC
 setup

Dear Ingo,

At 03/01/2017 05:04 PM, Ingo Molnar wrote:
[...]
>> +		pr_info("Not init interrupt remapping due to skipped IO-APIC setup\n");
>
> So you replaced a perfectly readable kernel message:
>
>  -		pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
>
> ... with an unreadable one:
>
>  +		pr_info("Not init interrupt remapping due to skipped IO-APIC setup\n");
>
> Why?

I am very sorry.

Because of my weak English skills :) . I am trying to improve my
English ability.

>
> Also, the changelog is pretty much unreadable as well:
>
>> As the commit 2e63ad4bd5dd ("x86/apic: Do not init irq remapping
>> if ioapic is disabled") added the judgement of skipped IO APIC
>> setup at the beginning of enable_IR_x2apic(). It may be redundant
>> that we check it again when we try to enable the interrupt mapping.
>>
>> So, remove the one in try_to_enable_IR() and refine them for
>> better readability.
>
> I edited it to:

Thanks very much ! it became very clear.

>
>    The following commit:
>
>      2e63ad4bd5dd ("x86/apic: Do not init irq remapping if ioapic is disabled")
>
>    ... added a check for skipped IO-APIC setup to enable_IR_x2apic(), but this

Could you tell me what is the meaning of "..." . How to use it?

>    check is also duplicated in try_to_enable_IR() - and it will never succeed in
>    calling irq_remapping_enable().
>
>    Remove the whole irq_remapping_enable() complication: if the IO-APIC is
>    disabled we cannot enable IRQ remapping.
>
> And I restored the original pr_info() message as well.

Yes. Thanks!

Sincerely,

	Liyang



>
> Thanks,
>
> 	Ingo
>
>
>