Messages in this thread |  | | Subject | Re: [PATCH] mm: cma: improve pr_debug log in cma_release() | From | Vlastimil Babka <> | Date | Fri, 27 Nov 2020 16:49:43 +0100 |
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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@codeaurora.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
> --- > 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); > >
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