On Fri, Dec 04, 2015 at 06:15:02PM +0100, Vlastimil Babka wrote:
> On 12/03/2015 08:11 AM, Joonsoo Kim wrote:
> >It doesn't make sense that we reset defer counter
> >in compaction_defer_reset() when compaction request under the order of
> >compact_order_failed succeed. Fix it.
>
> Right.
>
> >And, it does make sense that giving enough chance for updated failed
> >order compaction before deferring. Change it.
>
> Sorry, can't understand the meaning here. From the code it seems
> that you want to reset defer_shift to 0 instead of increasing it,
> when the current order is lower than the failed one? That makes
> sense, yeah.
You correctly understand my intention. :)
> How about this?
>
> "On the other hand, when deferring compaction for an order lower
> than the current compact_order_failed, we can assume the lower order
> will recover more quickly, so we should reset the progress made
> previously on compact_defer_shift with the higher order."
Will add it.
>
> >Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
>
> Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Thanks.
>
> >---
> > mm/compaction.c | 19 +++++++++++--------
> > 1 file changed, 11 insertions(+), 8 deletions(-)
> >
> >diff --git a/mm/compaction.c b/mm/compaction.c
> >index 67b8d90..1a75a6e 100644
> >--- a/mm/compaction.c
> >+++ b/mm/compaction.c
> >@@ -126,11 +126,14 @@ static struct page *pageblock_pfn_to_page(unsigned long start_pfn,
> > */
> > static void defer_compaction(struct zone *zone, int order)
> > {
> >- zone->compact_considered = 0;
> >- zone->compact_defer_shift++;
> >-
> >- if (order < zone->compact_order_failed)
> >+ if (order < zone->compact_order_failed) {
> >+ zone->compact_considered = 0;
> >+ zone->compact_defer_shift = 0;
> > zone->compact_order_failed = order;
> >+ } else {
> >+ zone->compact_considered = 0;
> >+ zone->compact_defer_shift++;
> >+ }
> >
> > if (zone->compact_defer_shift > COMPACT_MAX_DEFER_SHIFT)
> > zone->compact_defer_shift = COMPACT_MAX_DEFER_SHIFT;
> >@@ -161,11 +164,11 @@ bool compaction_deferred(struct zone *zone, int order)
> > /* Update defer tracking counters after successful compaction of given order */
> > static void compaction_defer_reset(struct zone *zone, int order)
> > {
> >- zone->compact_considered = 0;
> >- zone->compact_defer_shift = 0;
> >-
> >- if (order >= zone->compact_order_failed)
> >+ if (order >= zone->compact_order_failed) {
> >+ zone->compact_considered = 0;
> >+ zone->compact_defer_shift = 0;
> > zone->compact_order_failed = order + 1;
> >+ }
> >
> > trace_mm_compaction_defer_reset(zone, order);
> > }
> >
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@xxxxxxxxx. For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>