Re: [PATCH v1 1/1] mm: buddy page accessed before initialized

[Michal Hocko]

On Thu 02-11-17 12:10:39, Pavel Tatashin wrote:
> > > 
> > > Yes, but as I said, unfortunately memset(1) with CONFIG_VM_DEBUG does not
> > > catch this case. So, when CONFIG_VM_DEBUG is enabled kexec reboots without
> > > issues.
> > 
> > Can we make the init pattern to catch this?
> 
> Unfortunately, that is not easy: memset() gives us only one byte to play
> with, and if we use something else that will make CONFIG_VM_DEBUG
> unacceptably slow.

Why cannot we do something similar to the optimized struct page
initialization and write 8B at the time and fill up the size unaligned
chunk in 1B?
-- 
Michal Hocko
SUSE Labs