On 2024/11/3 04:16, Qiang Liu wrote:
If the last cycle reads bogus compound_order() and blockpfn > end_pfn occurs,
if blockpfn > end_pfn occurs, we will reset the blockpfn, right?
/*
* Be careful to not go outside of the pageblock.
*/
if (unlikely(blockpfn > end_pfn))
blockpfn = end_pfn;
So how this can happen?
it is possible that total_isolated will be less than nr_scanned. In this case,
strict mode should return 0, but the “if (strict && blockpfn < end_pfn)”
statement cannot recognize this situation
Signed-off-by: Qiang Liu <liuq131@xxxxxxxxxxxxxxx>
---
mm/compaction.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/compaction.c b/mm/compaction.c
index a2b16b08cbbf..6009f5d1021a 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -699,7 +699,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
* pages requested were isolated. If there were any failures, 0 is
* returned and CMA will fail.
*/
- if (strict && blockpfn < end_pfn)
+ if (strict && (blockpfn < end_pfn || total_isolated != nr_scanned))
total_isolated = 0;
cc->total_free_scanned += nr_scanned;
