linux-kernel - Re: [PATCH] x86, efi: change name of efi_no_storage_paranoia parameter to efi_storage

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Message-ID: <528DCED7.5070806@jp.fujitsu.com>
Date:	Thu, 21 Nov 2013 18:13:59 +0900
From:	Yasuaki Ishimatsu <isimatu.yasuaki@...fujitsu.com>
To:	joeyli <jlee@...e.com>
CC:	Madper Xie <cxie@...hat.com>,
	Matt Fleming <matt@...sole-pimps.org>,
	Richard Weinberger <richard@....at>,
	<linux-efi@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<matt.fleming@...el.com>, <matthew.garrett@...ula.com>
Subject: Re: [PATCH] x86, efi: change name of efi_no_storage_paranoia parameter
 to efi_storage_paranoia

(2013/11/20 17:08), joeyli wrote:
> 於 三，2013-11-20 於 15:26 +0900，Yasuaki Ishimatsu 提到：
>> (2013/11/19 12:16), Madper Xie wrote:
>>>
>>> isimatu.yasuaki@...fujitsu.com writes:
>>>
>>>> Hi Matt,
>>>>
>>>> Sorry for late the reply.
>>>>
>>>>
>>>> (2013/11/11 19:54), Matt Fleming wrote:
>>>>> On Mon, 11 Nov, at 05:52:59PM, Yasuaki Ishimatsu wrote:
>>>>>> Hi Matt,
>>>>>>
>>>>>> I uses FUJITSU's x86 box.
>>>>>> This does not become bricked even if I use all efi variable storage.
>>>>>> Thus I want a way to not need to specify efi_no_storage_paranoia
>>>>>> parameter.
>>>>>
>>>>> The efi_no_storage_paranoia parameter was introduced because some
>>>>> machines do not initiate garbage collection of the NVRAM until you
>>>>> allocate all space - basically it's a switch to turn off the "save 5KB
>>>>> of stoarge at all times" workaround that is needed to avoid bricking
>>>>> some machines.
>>>>>
>>>>> The intention of the switch is not to allow you to fill your NVRAM just
>>>>> because you can. If that is something you want to do then I think it's
>>>>> fair to require you to explicitly turn on efi_no_storage_paranoia. But
>>>>> I'm assuming here that you are doing something like writing lots and
>>>>> lots of pstore entries and just want to write as many as your variable
>>>>> storage will allow? Or are you doing something more fundamental like
>>>>> creating BootXXXX entries?
>>>>>
>>>>> What are you doing to run into the 5KB reserve? How much NVRAM does your
>>>>> machine come with?
>>>>
>>>> I just add boot entry to NVRAM by efibootmgr command. But when Linux boots up,
>>>> the remaining NVRAM is less than 5Kbyte. So I cannnot add new entry.
>>>>
>>> Howdy Yasuaki,
>>>     If the remaining NVRAM is less than 5Kb, your writing will trigger a
>>>     NVRAM storage reclamation. However you still failed creating entry. So
>>>     I'm just curious what itmes occupy lots of nvram storage space.
>>
>> Even if we got EFI_OUT_OF_RESOURCES while running Linux, gc does not run.
>> Trigger of gc is when EFI_OUT_OF_RESOURCES occurs on pre OS environment with
>> UEFI. So on my system, if EFI_OUT_OF_RESOURCES occurs by the 5Kbyte threshold,
>> we cannot use nvram storage until EFI_OUT_OF_RESOURCES occurs on pre OS
>> environment with UEFI.
>>
>> Thanks,
>> Yasuaki Ishimatsu
>
> Can we try to trigger gc by EFI_OUT_OF_RESOURCE in EFI stub kernel or
> EFI boot loader to recover NVRAM space? Does work with the BIOS on this
> machine?

Yes. I can trigger gc by EFI_OUT_OF_RESOUCE in EFI shell on my machine.

Thanks,
Yasuaki Ishimatu

>
>
> Thanks a lot!
> Joey Lee
>


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