Re: [PATCH] Only reset e820 once, even with multiple memmap=exactmap params

Yinghai Lu
2013-01-10T17:11:59Z

On Thu, Jan 10, 2013 at 9:01 AM, Vivek Goyal <vgoyal@redhat.com> wrote:
> On Thu, Jan 10, 2013 at 08:53:18AM -0800, Yinghai Lu wrote:
>> On Thu, Jan 10, 2013 at 6:26 AM, Vivek Goyal <vgoyal@redhat.com> wrote:
>> >
>> > This happens only in case of kdump and not kexec. In case of kdump
>> > we want second kernel to use only selected memory areas.
>> >
>> > In fact this is one improvement area. Instead of using memmap= entries
>> > in kdump case, we should probably modify the e820 map passed in
>> > zero page and get rid of memmap= entries.
>>
>> then how the kdump kernel get saved_max_pfn?
>>
>
> Oh, I forgot about that. May be we can pass saved_max_pfn on command line
> instead of passing all memmap= entries.

then we create another kernel version/kexec tools dependency.

kexec tools need to check kernel version, to see if saved_max_pfn= is supported.