The patch titled
Subject: mm: cma: improve pr_debug log in cma_release()
has been added to the -mm tree. Its filename is
mm-cma-improve-pr_debug-log-in-cma_release.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-cma-improve-pr_debug-log-in-cma_release.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-cma-improve-pr_debug-log-in-cma_release.patch
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------------------------------------------------------
From: Charan Teja Reddy <charante@xxxxxxxxxxxxxx>
Subject: mm: cma: improve pr_debug log in cma_release()
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.
Link: https://lkml.kernel.org/r/1606318341-29521-1-git-send-email-charante@xxxxxxxxxxxxxx
Signed-off-by: Charan Teja Reddy <charante@xxxxxxxxxxxxxx>
Reviewed-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/cma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/cma.c~mm-cma-improve-pr_debug-log-in-cma_release
+++ a/mm/cma.c
@@ -510,7 +510,7 @@ bool cma_release(struct cma *cma, const
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);
_
Patches currently in -mm which might be from charante@xxxxxxxxxxxxxx are
mm-cma-improve-pr_debug-log-in-cma_release.patch
