revert "mm: have order > 0 compaction start off where it left"

This reverts commit 7db8889ab05b ("mm: have order > 0 compaction start
off where it left") and commit de74f1cc ("mm: have order > 0 compaction
start near a pageblock with free pages").  These patches were a good
idea and tests confirmed that they massively reduced the amount of
scanning but the implementation is complex and tricky to understand.  A
later patch will cache what pageblocks should be skipped and
reimplements the concept of compact_cached_free_pfn on top for both
migration and free scanners.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Richard Davies <richard@arachsys.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Avi Kivity <avi@redhat.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 6 deletions

diff --git a/mm/internal.h b/mm/internal.h
index 97664be2ca37..6f6bb9ab9386 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -118,14 +118,8 @@ struct compact_control {
         unsigned long nr_freepages;     /* Number of isolated free pages */
         unsigned long nr_migratepages;  /* Number of pages to migrate */
         unsigned long free_pfn;         /* isolate_freepages search base */
-        unsigned long start_free_pfn;   /* where we started the search */
         unsigned long migrate_pfn;      /* isolate_migratepages search base */
         bool sync;                      /* Synchronous migration */
-        bool wrapped;                   /* Order > 0 compactions are
-                                           incremental, once free_pfn
-                                           and migrate_pfn meet, we restart
-                                           from the top of the zone;
-                                           remember we wrapped around. */
 
         int order;                      /* order a direct compactor needs */
         int migratetype;                /* MOVABLE, RECLAIMABLE etc */