From mboxrd@z Thu Jan  1 00:00:00 1970
Return-path: <kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org>
Received: from g4t0016.houston.hp.com ([15.201.24.19])
 by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux))
 id 1VVzUQ-0008Kw-C3
 for kexec@lists.infradead.org; Tue, 15 Oct 2013 07:56:27 +0000
Message-ID: <525CF507.7000705@hp.com>
Date: Tue, 15 Oct 2013 15:55:51 +0800
From: Jingbai Ma <jingbai.ma@hp.com>
MIME-Version: 1.0
Subject: Re: [PATCH v3] makedumpfile: fix max_mapnr issue on system has over
 44-bit addressing
References: <20131014121648.1409.58312.stgit@k.asiapacific.hpqcorp.net>
 <525CD97B.3070209@jp.fujitsu.com>
In-Reply-To: <525CD97B.3070209@jp.fujitsu.com>
List-Id: <kexec.lists.infradead.org>
List-Unsubscribe: <http://lists.infradead.org/mailman/options/kexec>,
 <mailto:kexec-request@lists.infradead.org?subject=unsubscribe>
List-Archive: <http://lists.infradead.org/pipermail/kexec/>
List-Post: <mailto:kexec@lists.infradead.org>
List-Help: <mailto:kexec-request@lists.infradead.org?subject=help>
List-Subscribe: <http://lists.infradead.org/mailman/listinfo/kexec>,
 <mailto:kexec-request@lists.infradead.org?subject=subscribe>
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Sender: "kexec" <kexec-bounces@lists.infradead.org>
Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org
To: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: bhe@redhat.com, nishimura@mxp.nes.nec.co.jp, usui@mxm.nes.nec.co.jp, lisa.mitchell@hp.com, vgoyal@redhat.com, ruyang@redhat.com, tachibana@mxm.nes.nec.co.jp, anderson@redhat.com, chaowang@redhat.com, kumagai-atsushi@mxc.nes.nec.co.jp, kexec@lists.infradead.org, Jingbai Ma <jingbai.ma@hp.com>, crash-utility@redhat.com

On 10/15/2013 01:58 PM, HATAYAMA Daisuke wrote:
> (2013/10/14 21:16), Jingbai Ma wrote:
> <cut>
>> @@ -125,7 +126,7 @@ get_max_mapnr(void)
>> unsigned long long max_paddr;
>>
>> if (info->flag_refiltering) {
>> - info->max_mapnr = info->dh_memory->max_mapnr;
>> + info->max_mapnr = info->kh_memory->max_mapnr_64;
>> return TRUE;
>> }
>>
>
> Please:
>
> if (dh.header_version < 6)
> info->max_mapnr = info->dh_memmory->max_mapnr;
> else
> info->max_mapnr = info->kh_memory->max_mapnr_64;

If we deal the max_mapnr_64 as below I did, we do not have to check 
header_version everywhere when we need to the value max_mapnr. I just 
set it to max_mapnr_64 regardless it's old version or new in the first 
place we get it. It can simplify the code logic in all code. Or we have 
to add this version check, it's also error prone.

>
>> @@ -783,6 +784,10 @@ get_kdump_compressed_header_info(char *filename)
>> ERRMSG("header does not have dump_level member\n");
>> return FALSE;
>> }
>> +
>> + if (dh.header_version < 6)
>> + kh.max_mapnr_64 = dh.max_mapnr;
>> +
>
> Again, please don't do this. It's confusing if in-memory header data
> is not identical to in-disk one.
>

I have explained the reason why I set the kh.max_mapnr_64 for old 
version here.
If you still think we shouldn't change this value, and should check 
header_version everywhere when need max_mapnr, I will send a new version 
to change it.


-- 
Thanks,
Jingbai Ma

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec