From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753984Ab3KUJyY (ORCPT ); Thu, 21 Nov 2013 04:54:24 -0500 Received: from smtp.nue.novell.com ([195.135.221.5]:46586 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751133Ab3KUJyV (ORCPT ); Thu, 21 Nov 2013 04:54:21 -0500 Subject: Re: [PATCH] x86, efi: change name of efi_no_storage_paranoia parameter to efi_storage_paranoia From: joeyli To: Yasuaki Ishimatsu Cc: Madper Xie , Matt Fleming , Richard Weinberger , linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, matt.fleming@intel.com, matthew.garrett@nebula.com In-Reply-To: <528DCED7.5070806@jp.fujitsu.com> References: <527C93B5.7010407@jp.fujitsu.com> <527C9B5C.6040509@nod.at> <527CB013.30200@jp.fujitsu.com> <527CB0F4.8080606@nod.at> <527CBC05.6080505@jp.fujitsu.com> <527CBD01.1000908@nod.at> <527CBDD3.2020609@jp.fujitsu.com> <20131108143421.GB22636@console-pimps.org> <52809AEB.9080100@jp.fujitsu.com> <20131111105424.GD22636@console-pimps.org> <528AD50D.6060503@jp.fujitsu.com> <87siutqdwv.fsf@redhat.com> <528C562B.3070008@jp.fujitsu.com> <1384934881.6516.4082.camel@linux-s257.site> <528DCED7.5070806@jp.fujitsu.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 21 Nov 2013 17:53:43 +0800 Message-ID: <1385027623.6516.4090.camel@linux-s257.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 於 四，2013-11-21 於 18:13 +0900，Yasuaki Ishimatsu 提到： > (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@jp.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 > OK, then maybe can try to trigger gc in EFI stub before ExitBootService(). Another problem is what's the reasonable threshold. The threshold should bigger then 5Kbyte, then we write a dummy BootTime NV variable to trigger gc. Thanks Joey Lee