[PATCH 1/3] mm/page_isolation: return last tested pfn rather than failure indicator

From: Joonsoo Kim
Date: Mon Nov 09 2015 - 02:24:36 EST


This is preparation step to report test failed pfn in new tracepoint
to analyze cma allocation failure problem. There is no functional change
in this patch.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
mm/page_isolation.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 4568fd5..6f5ae96 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -212,7 +212,7 @@ int undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
*
* Returns 1 if all pages in the range are isolated.
*/
-static int
+static unsigned long
__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn,
bool skip_hwpoisoned_pages)
{
@@ -237,9 +237,8 @@ __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn,
else
break;
}
- if (pfn < end_pfn)
- return 0;
- return 1;
+
+ return pfn;
}

int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
@@ -248,7 +247,6 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
unsigned long pfn, flags;
struct page *page;
struct zone *zone;
- int ret;

/*
* Note: pageblock_nr_pages != MAX_ORDER. Then, chunks of free pages
@@ -266,10 +264,11 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
/* Check all pages are free or marked as ISOLATED */
zone = page_zone(page);
spin_lock_irqsave(&zone->lock, flags);
- ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn,
+ pfn = __test_page_isolated_in_pageblock(start_pfn, end_pfn,
skip_hwpoisoned_pages);
spin_unlock_irqrestore(&zone->lock, flags);
- return ret ? 0 : -EBUSY;
+
+ return (pfn < end_pfn) ? -EBUSY : 0;
}

struct page *alloc_migrate_target(struct page *page, unsigned long private,
--
1.9.1

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