On Tue, Jun 22, 2021 at 5:34 PM Gavin Shan <gshan@xxxxxxxxxx> wrote: > > The macro PAGE_REPORTING_MIN_ORDER is defined as the page reporting > threshold. It can't be adjusted at runtime. > > This introduces a variable (@page_reporting_order) to replace the > marcro (PAGE_REPORTING_MIN_ORDER). It's also exported so that the > page reporting order can be adjusted at runtime. > > Suggested-by: David Hildenbrand <david@xxxxxxxxxx> > Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx> > --- > Documentation/admin-guide/kernel-parameters.txt | 6 ++++++ > mm/page_reporting.c | 8 ++++++-- > mm/page_reporting.h | 5 ++--- > 3 files changed, 14 insertions(+), 5 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index cb89dbdedc46..566c4b9af3cd 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -3566,6 +3566,12 @@ > off: turn off poisoning (default) > on: turn on poisoning > > + page_reporting.page_reporting_order= > + [KNL] Minimal page reporting order > + Format: <integer> > + Adjust the minimal page reporting order. The page > + reporting is disabled when it exceeds (MAX_ORDER-1). > + Based on the issue found by Stephen I think we may need to tweak this a bit. I think we may want to just default this value to MAX_ORDER. We can override this value at registration time with the value provided either by the reporting device or pageblock_order if prdev->order is not set. > diff --git a/mm/page_reporting.c b/mm/page_reporting.c > index df9c5054e1b4..293a8713ef7c 100644 > --- a/mm/page_reporting.c > +++ b/mm/page_reporting.c > @@ -10,6 +10,10 @@ > #include "page_reporting.h" > #include "internal.h" > > +unsigned int page_reporting_order = pageblock_order; Rather than setting this to pageblock_order directly you can set this to MAX_ORDER which should be constant. Then we can just add some checks in page_reporting_register to update it when pageblock_order is less than page_reporting_order. Then in the next patch you could tweak it so that it will use "prdev->order ? : pageblock_order" instead of just pageblock_order.
