Re: [PATCH] mm/cma: print total and used pages in cma_alloc()

[Andrew Morton <akpm@linux-foundation.org>]

On Sat, 16 Aug 2025 08:27:39 +0200 David Hildenbrand <david@redhat.com> wrote:

> > @@ -858,8 +869,8 @@ static struct page *__cma_alloc(struct cma *cma, unsigned long count,
> >   	if (!cma || !cma->count)
> >   		return page;
> >   
> > -	pr_debug("%s(cma %p, name: %s, count %lu, align %d)\n", __func__,
> > -		(void *)cma, cma->name, count, align);
> > +	pr_debug("%s(cma %p, name: %s, total pages: %lu, used pages: %lu, request pages: %lu, align %d)\n",
> > +		__func__, (void *)cma, cma->name, cma->count, cma_get_used_pages(cma), count, align);
> 
> 		^ one space missing for proper indentation.
> 
> But doing another spinlock cycle just for debugging purposes? That does 
> not feel right, sorry.

If we're calling pr_debug() frequently enough for this to matter, we
have other problems!