Merge: Revert "mm/compaction: fix set skip in fast_find_migrateblock"

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/1996

    Revert "mm/compaction: fix set skip in fast_find_migrateblock"

    This reverts commit 7efc3b7.

    We have got openSUSE reports (Link 1) for 6.1 kernel with khugepaged
    stalling CPU for long periods of time.  Investigation of tracepoint data
    shows that compaction is stuck in repeating fast_find_migrateblock()
    based migrate page isolation, and then fails to migrate all isolated
    pages.

    Commit 7efc3b7 ("mm/compaction: fix set skip in fast_find_migrateblock")
    was suspected as it was merged in 6.1 and in theory can indeed remove a
    termination condition for fast_find_migrateblock() under certain
    conditions, as it removes a place that always marks a scanned pageblock
    from being re-scanned.  There are other such places, but those can be
    skipped under certain conditions, which seems to match the tracepoint
    data.

    Testing of revert also appears to have resolved the issue, thus revert
    the commit until a more robust solution for the original problem is
    developed.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2166447

Signed-off-by: Nico Pache <npache@redhat.com>

Approved-by: Waiman Long <longman@redhat.com>
Approved-by: Rafael Aquini <aquini@redhat.com>

Signed-off-by: Herton R. Krzesinski <herton@redhat.com>

Author: Herton R. Krzesinski

mm/compaction.c

@@ -1862,6 +1862,7 @@ static unsigned long fast_find_migrateblock(struct compact_control *cc)
 					pfn = cc->zone->zone_start_pfn;
 				cc->fast_search_fail = 0;
 				found_block = true;
+				set_pageblock_skip(freepage);
 				break;
 			}
 		}