Re: [PATCH] mm: move page_ext_init after all struct pages are initialized

[Andrew Morton]

On Thu, 19 May 2016 15:35:15 -0700 "Shi, Yang" <yang.shi@xxxxxxxxxx> wrote:

> On 5/19/2016 3:30 PM, Andrew Morton wrote:
> > On Thu, 19 May 2016 14:29:05 -0700 Yang Shi <yang.shi@xxxxxxxxxx> wrote:
> >
> >> When DEFERRED_STRUCT_PAGE_INIT is enabled, just a subset of memmap at boot
> >> are initialized, then the rest are initialized in parallel by starting one-off
> >> "pgdatinitX" kernel thread for each node X.
> >>
> >> If page_ext_init is called before it, some pages will not have valid extension,
> >> so move page_ext_init() after it.
> >>
> >
> > <stdreply>When fixing a bug, please fully describe the end-user impact
> > of that bug</>
> 
> The kernel ran into the below oops which is same with the oops reported 
> in 
> http://ozlabs.org/~akpm/mmots/broken-out/mm-page_is_guard-return-false-when-page_ext-arrays-are-not-allocated-yet.patch.

So this patch makes
mm-page_is_guard-return-false-when-page_ext-arrays-are-not-allocated-yet.patch
obsolete?