Messages in this thread | | | Date | Mon, 19 Nov 2007 13:08:01 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] Cast page_to_pfn to unsigned long in CONFIG_SPARSEMEM |
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On Mon, 19 Nov 2007 15:20:23 -0500 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
> * 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.
formally ptrdiff_t, I believe.
> 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 */
I'd have thought that __pfn_to_page() was the place to fix this: the lower-level point. Because someone might later start using __pfn_to_page() for something.
Heaven knows why though - why does __pfn_to_page() even exist? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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