From: "George G. Davis" <davis.george@xxxxxxxxxxx> 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/20210823202823.13765-1-george_davis@xxxxxxxxxx Signed-off-by: George G. Davis <davis.george@xxxxxxxxxxx> Cc: Eugeniu Rosca <erosca@xxxxxxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_isolation.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) --- 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; } _
