linux-kernel - Re: [PATCH] x86, efi: print debug values in Kib not MB

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Message-ID: <53D82118.6090202@redhat.com>
Date:	Tue, 29 Jul 2014 18:32:56 -0400
From:	Prarit Bhargava <prarit@...hat.com>
To:	Borislav Petkov <bp@...en8.de>
CC:	linux-kernel@...r.kernel.org, lszubowi@...hat.com,
	Matt Fleming <matt.fleming@...el.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
	linux-efi@...r.kernel.org
Subject: Re: [PATCH] x86, efi: print debug values in Kib not MB



On 07/29/2014 06:29 PM, Borislav Petkov wrote:
> On Tue, Jul 29, 2014 at 01:09:21PM -0400, Prarit Bhargava wrote:
>> The current debug print in EFI does
>>
>> [    0.000000] efi: mem84: type=3, attr=0xf, range=[0x00000000645b5000-0x00000000645fb000) (0MB)
>>
>> and rounds off the size to 0MB and isn't very useful.  We should print this in
>> Kib.  After applying this patch we get better info with
>>
>> [    0.000000] efi: mem84: type=3, attr=0xf, range=[0x00000000645b5000-0x00000000645fb000) (280kiB)
> 
> Turning this into kiB unconditionally won't always work ok:
> 
> First of all, there might be something which parses that output so I'd
> make sure I'm not breaking that. Maybe fwts... Matt will know.
> 
> Then, I have an UEFI region which is > 13G:
> 
> [    0.000000] efi: mem42: type=7, attr=0xf, range=[0x0000000100000000-0x0000000450000000) (13568MB)
> 
> 
> With your patch it is even worse:
> 
> [    0.000000] efi: mem42: type=7, attr=0xf, range=[0x0000000100000000-0x0000000450000000) (13893632kiB)
> 
> 
> I'd guess you'll have to go all out and do this properly. :-)
> 
> Something like showing the highest unit which is still > 1. In the above
> case, this should be (13GB) or maybe even introduce fractions.
> 
> Depends on how involved this output should be.

Yeah, I thought about doing something like that but figured if I'm at this level
I can do some math ;), and it was best to keep the code simple with a KiB.

Matt -- will anything be broken here if we change the output?

P.

> 
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