While looking at some really long hugetlb page allocation times, I noticed
instances where should_compact_retry() was returning true more often that
I expected. In one allocation attempt, it returned true 765668 times in a
row. To me, this was unexpected because of the following:
#define MAX_COMPACT_RETRIES 16
int max_retries = MAX_COMPACT_RETRIES;
However, if should_compact_retry() returns true via the following path we
do not increase the retry count.
/*
* make sure the compaction wasn't deferred or didn't bail out early
* due to locks contention before we declare that we should give up.
* But do not retry if the given zonelist is not suitable for
* compaction.
*/
if (compaction_withdrawn(compact_result)) {
ret = compaction_zonelist_suitable(ac, order, alloc_flags);
goto out;
}
Just curious, is this intentional?
--
Mike Kravetz
