Subject: Re: [PATCH] fadump: Register the memory reserved by fadump

From: Srikar Dronamraju <[email-masked]>
Date: Fri, 5 Aug 2016 12:58:38 +0530

* Michael Ellerman <[email-masked]> [2016-08-05 17:07:01]:

> Srikar Dronamraju <[email-masked]> writes:
> 
> > Fadump kernel reserves large chunks of memory even before the pages are
> > initialized. This could mean memory that corresponds to several nodes might
> > fall in memblock reserved regions.
> >
> ...
> > Register the memory reserved by fadump, so that the cache sizes are
> > calculated based on the free memory (i.e Total memory - reserved
> > memory).
> 
> The memory is reserved, with memblock_reserve(). Why is that not sufficient?
> 
> cheers
> 

Because at page initialization time, the kernel doesnt know how many
pages are reserved. One way to do that would be to walk through the
different memory reserved blocks and calculate the size. But Mel feels
thats an overhead (from his reply to the other thread) esp for just one
use case.

-- 
Thanks and Regards
Srikar Dronamraju