Re: [PATCH 0/3] OOM detection rework v4

From: Hillf Danton
Date: Fri Feb 26 2016 - 05:28:25 EST


>>
> > --- a/mm/page_alloc.c Thu Feb 25 15:43:18 2016
> > +++ b/mm/page_alloc.c Fri Feb 26 15:18:55 2016
> > @@ -3113,6 +3113,8 @@ should_reclaim_retry(gfp_t gfp_mask, uns
> > struct zone *zone;
> > struct zoneref *z;
> >
> > + if (order <= PAGE_ALLOC_COSTLY_ORDER)
> > + return true;
>
> This is defeating the whole purpose of the rework - to behave
> deterministically. You have just disabled the oom killer completely.
> This is not the way to go
>
Then in another direction, below is what I can do.

thanks
Hillf
--- a/mm/page_alloc.c Thu Feb 25 15:43:18 2016
+++ b/mm/page_alloc.c Fri Feb 26 18:14:59 2016
@@ -3366,8 +3366,11 @@ retry:
no_progress_loops++;

if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
- did_some_progress > 0, no_progress_loops))
+ did_some_progress > 0, no_progress_loops)) {
+ /* Burn more cycles if any zone seems to satisfy our request */
+ no_progress_loops /= 2;
goto retry;
+ }

/* Reclaim has failed us, start killing things */
page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
--