On Mon, Aug 9, 2021 at 12:25 AM David Hildenbrand <david@xxxxxxxxxx> wrote: > > On 05.08.21 21:02, Zi Yan wrote: > > From: Zi Yan <ziy@xxxxxxxxxx> > > > > page_reporting_order was set to MAX_ORDER, which is always smaller than > > a memory section size. An upcoming change will make MAX_ORDER larger > > than a memory section size. Set page_reporting_order to > > PFN_SECTION_SHIFT to match existing size assumption. > > > > Signed-off-by: Zi Yan <ziy@xxxxxxxxxx> > > Cc: David Hildenbrand <david@xxxxxxxxxx> > > Cc: linux-mm@xxxxxxxxx > > Cc: linux-kernel@xxxxxxxxxxxxxxx > > --- > > mm/page_reporting.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/mm/page_reporting.c b/mm/page_reporting.c > > index 382958eef8a9..dc4a2d699862 100644 > > --- a/mm/page_reporting.c > > +++ b/mm/page_reporting.c > > @@ -11,7 +11,8 @@ > > #include "page_reporting.h" > > #include "internal.h" > > > > -unsigned int page_reporting_order = MAX_ORDER; > > +/* Set page_reporting_order at section size */ > > +unsigned int page_reporting_order = PFN_SECTION_SHIFT; > > module_param(page_reporting_order, uint, 0644); > > MODULE_PARM_DESC(page_reporting_order, "Set page reporting order"); > > > > > > If you look closely, this is only a placeholder and will get overwritten > in page_reporting_register(). I don't recall why we have the module > parameter at all. Most probably, to adjust the reporting order after we > already registered a user. Can't we just initialize that to 0 ? Yeah, it is pretty much there for debugging in the event that we are on an architecture that is misconfigured.
