Re: [RFC PATCH 0/5] crash dump bitmap: scan memory pages in kernel to speedup kernel dump process

Eric W. Biederman
2013-03-08T16:19:20Z

Vivek Goyal <vgoyal@redhat.com> writes:

> On Thu, Mar 07, 2013 at 01:54:45PM -0800, Eric W. Biederman wrote:
>> Vivek Goyal <vgoyal@redhat.com> writes:
>> > I think this is not a good idea. It has several issues.
>>
>> Actually it does not appear to be doing any work in the first kernel.
>
> Looks like patch3 in series is doing that.
>
> machine_crash_shutdown(&fixed_regs);
> + generate_crash_dump_bitmap();
> machine_kexec(kexec_crash_image);
>
> So this bitmap seems to be being set just before transitioning into
> second kernel.
>
> I am sure you would not like this extra code in this path. :-)

Ouch! I had totally missed that. No that is not at all acceptable.

I was blind that day. The only call I saw was in patch 4 that put
the call generated the bitmap in the new proc file.

Eric