Re: [PATCH] Cast page_to_pfn to unsigned long in CONFIG_SPARSEMEM

Mathieu Desnoyers
2007-11-19T20:20:35Z

* Dave Hansen (haveblue@us.ibm.com) wrote:
> The only thing I might suggest doing differently is actually using the
> page_to_pfn() definition itself:
>
> memory_model.h:#define page_to_pfn __page_to_pfn
>
> The full inline function version should do this already, and we
> shouldn't have any real direct __page_to_pfn() users anyway.
>

Like this then..

Cast page_to_pfn to unsigned long in CONFIG_SPARSEMEM

Make sure the type returned by page_to_pfn is always unsigned long. If we
don't cast it explicitly, it can be int on i386, but long on x86_64. This is
especially inelegant for printks.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Dave Hansen <haveblue@us.ibm.com>
CC: linux-mm@kvack.org
CC: linux-kernel@vger.kernel.org
---
include/asm-generic/memory_model.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6-lttng/include/asm-generic/memory_model.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-generic/memory_model.h 2007-11-19 15:06:40.000000000 -0500
+++ linux-2.6-lttng/include/asm-generic/memory_model.h 2007-11-19 15:18:57.000000000 -0500
@@ -76,7 +76,7 @@ struct page;
extern struct page *pfn_to_page(unsigned long pfn);
extern unsigned long page_to_pfn(struct page *page);
#else
-#define page_to_pfn __page_to_pfn
+#define page_to_pfn ((unsigned long)__page_to_pfn)
#define pfn_to_page __pfn_to_page
#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */