[PATCH 0/2] Fix early boot OOM issues for some platforms

[Simon Horman]

On Tue, Apr 06, 2021 at 03:11:51PM +0100, Hongyan Xia wrote:
> From: Hongyan Xia <hongyxia at amazon.com>
> 
> We have observed a couple of cases where after a successful kexec, the
> crash kernel loaded in the 2nd kernel will run out of memory and
> crash. We narrowed down to two issues:
> 
> 1. when preparing the memory map, kexec excludes the Interrupt Vector
>    Table. However, the end address of IVT is incorrect.
> 2. The wrong end address of IVT is not 1KiB aligned. When preparing the
>    crashkernel, the memory map will reject unaligned memory chunks. On
>    many x86 platforms this means the entire bottom 1MiB range is
>    excluded from the crashkernel memory map, resulting in OOM when the
>    crashkernel boots.
> 
> Patch 1 fixes 1 which is actually enough to eliminate the issue but we
> feel that such issue may happen again (e.g., with a weird BIOS that has
> unaligned e820 map), so we also have patch 2 to improve the handling of
> unaligned memory.
> 
> Hongyan Xia (2):
>   Fix where the real mode interrupt vector ends
>   Shrink segments to fit alignment instead of throwing them away

Thanks, series applied.