Re: [v6 01/15] x86/mm: reserve only exiting low pages

Michal Hocko
2017-08-14T11:40:18Z

On Fri 11-08-17 11:24:55, Pasha Tatashin wrote:
[...]
> >>In this patchset we will stop zeroing struct page memory during allocation.
> >>Therefore, this bug must be fixed in order to avoid random assert failures
> >>caused by CONFIG_DEBUG_VM_PGFLAGS triggers.
> >>
> >>The fix is to reserve memory from the first existing PFN.
> >
> >Hmm, I assume this is a result of some assert triggering, right? Which
> >one? Why don't we need the same treatment for other than x86 arch?
>
> Correct, the pgflags asserts were triggered when we were setting reserved
> flags to struct page for PFN 0 in which was never initialized through
> __init_single_page(). The reason they were triggered is because we set all
> uninitialized memory to ones in one of the debug patches.

And why don't we need the same treatment for other architectures?
--
Michal Hocko
SUSE Labs