[157/212] mm/page_isolation: tracing: trace all test_pages_isolated failures

Commit Message

Andrew Morton Sept. 2, 2021, 9:58 p.m. UTC

From: "George G. Davis" <[e-mail]>
Subject: mm/page_isolation: tracing: trace all test_pages_isolated failures

Some test_pages_isolated failure conditions don't include trace points. 
For debugging issues caused by "pinned" pages, make sure to trace all
calls whether they succeed or fail.  In this case, a failure case did not
result in a trace point.  So add the missing failure case in
test_pages_isolated traces.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: George G. Davis <[e-mail]>
Cc: Eugeniu Rosca <[e-mail]>
Cc: David Hildenbrand <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/page_isolation.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

Patch

--- a/mm/page_isolation.c~mm-page_isolation-tracing-trace-all-test_pages_isolated-failures
+++ a/mm/page_isolation.c
@@ -287,6 +287,7 @@  int test_pages_isolated(unsigned long st
 	unsigned long pfn, flags;
 	struct page *page;
 	struct zone *zone;
+	int ret;
 
 	/*
 	 * Note: pageblock_nr_pages != MAX_ORDER. Then, chunks of free pages
@@ -299,15 +300,21 @@  int test_pages_isolated(unsigned long st
 			break;
 	}
 	page = __first_valid_page(start_pfn, end_pfn - start_pfn);
-	if ((pfn < end_pfn) || !page)
-		return -EBUSY;
+	if ((pfn < end_pfn) || !page) {
+		ret = -EBUSY;
+		goto out;
+	}
+
 	/* Check all pages are free or marked as ISOLATED */
 	zone = page_zone(page);
 	spin_lock_irqsave(&zone->lock, flags);
 	pfn = __test_page_isolated_in_pageblock(start_pfn, end_pfn, isol_flags);
 	spin_unlock_irqrestore(&zone->lock, flags);
 
+	ret = pfn < end_pfn ? -EBUSY : 0;
+
+out:
 	trace_test_pages_isolated(start_pfn, end_pfn, pfn);
 
-	return pfn < end_pfn ? -EBUSY : 0;
+	return ret;
 }