On 11/25/20 4:32 PM, Charan Teja Reddy wrote:
It is required to print 'count' of pages, along with the pages, passed
to cma_release to debug the cases of mismatched count value passed
between cma_alloc() and cma_release() from a code path.
As an example, consider the below scenario:
1) CMA pool size is 4MB and
2) User doing the erroneous step of allocating 2 pages but freeing 1
page in a loop from this CMA pool.
The step 2 causes cma_alloc() to return NULL at one point of time
because of -ENOMEM condition.
And the current pr_debug logs is not giving the info about these types
of allocation patterns because of count value not being printed in
cma_release().
We are printing the count value in the trace logs, just extend the same
to pr_debug logs too.
Signed-off-by: Charan Teja Reddy <charante@xxxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
---
mm/cma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/cma.c b/mm/cma.c
index 7f415d7..07c904b 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -512,7 +512,7 @@ bool cma_release(struct cma *cma, const struct page *pages, unsigned int count)
if (!cma || !pages)
return false;
- pr_debug("%s(page %p)\n", __func__, (void *)pages);
+ pr_debug("%s(page %p, count %zu)\n", __func__, (void *)pages, count);
pfn = page_to_pfn(pages);
