[PATCH v2] mm/compaction: remove unnecessary detection code.

[Qiang Liu]

It is impossible for the situation where blockpfn > end_pfn to arise,
The if statement here is not only unnecessary, but may also lead to
a misunderstanding that blockpfn > end_pfn could potentially happen.
so these unnecessary checking code should be removed.

Signed-off-by: Qiang Liu <liuq131@xxxxxxxxxxxxxxx>
---
 mm/compaction.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index a2b16b08cbbf..baeda7132252 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -682,12 +682,6 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
 	if (locked)
 		spin_unlock_irqrestore(&cc->zone->lock, flags);
 
-	/*
-	 * Be careful to not go outside of the pageblock.
-	 */
-	if (unlikely(blockpfn > end_pfn))
-		blockpfn = end_pfn;
-
 	trace_mm_compaction_isolate_freepages(*start_pfn, blockpfn,
 					nr_scanned, total_isolated);
 
-- 
2.27.0