linux-kernel - Re: [PATCH v2] kdump x86: fix total mem size calculation for reservation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4F5B1305.4080306@gmail.com>
Date:	Sat, 10 Mar 2012 16:38:29 +0800
From:	Cong Wang <xiyou.wangcong@...il.com>
To:	Dave Young <dyoung@...hat.com>
CC:	linux-kernel@...r.kernel.org, x86@...nel.org,
	linux@....linux.org.uk, vgoyal@...hat.com
Subject: Re: [PATCH v2] kdump x86: fix total mem size calculation for reservation

On 03/10/2012 12:56 PM, Dave Young wrote:
> crashkernel reservation need know the total memory size. Current get_total_mem
> simply use max_pfn - min_low_pfn. It is wrong because it will including
> memory holes in the middle.
>
> Especially for kvm guest with memory>  0xe0000000, there's below in qemu code:
> qemu split memory as below:
>      if (ram_size>= 0xe0000000 ) {
>          above_4g_mem_size = ram_size - 0xe0000000;
>          below_4g_mem_size = 0xe0000000;
>      } else {
>          below_4g_mem_size = ram_size;
>      }
> So for 4G mem guest, seabios will insert a 512M usable region beyond of 4G.
> Thus in above case max_pfn - min_low_pfn will be more than original memsize.
>
> Fixing this issue by using memblock_phys_mem_size() to get the total memsize.
>
> [v1 ->  v2]: refresh the patch based on latest linus tree
>

Looks good to my eyes,

Reviewed-by: WANG Cong <xiyou.wangcong@...il.com>

Can you post the result of crashkernel after this patch to convince people?

Thanks.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/