Re: [2.6.30-rc8] gcc 3.3 : __udivdi3 undefined.

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

On Fri, 05 Jun 2009 13:00:28 +0900 Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> wrote:

> > Perhaps it's this:
> > 
> > static void __init memtest(u64 pattern, u64 start_phys, u64 size)
> > {
> > 	u64 i, count;
> > 	u64 *start;
> > 	u64 start_bad, last_bad;
> > 	u64 start_phys_aligned;
> > 	size_t incr;
> > 
> > 	incr = sizeof(pattern);
> > 	start_phys_aligned = ALIGN(start_phys, incr);
> > 	count = (size - (start_phys_aligned - start_phys))/incr;
> Bingo!

OK, thanks.  We should fix this for 2.6.30.

We could do the obvious:

--- a/arch/x86/mm/memtest.c~a
+++ a/arch/x86/mm/memtest.c
@@ -8,6 +8,7 @@
 #include <linux/pfn.h>
 
 #include <asm/e820.h>
+#include <asm/div64.h>
 
 static u64 patterns[] __initdata = {
 	0,
@@ -48,7 +49,8 @@ static void __init memtest(u64 pattern, 
 
 	incr = sizeof(pattern);
 	start_phys_aligned = ALIGN(start_phys, incr);
-	count = (size - (start_phys_aligned - start_phys))/incr;
+	count = size - (start_phys_aligned - start_phys);
+	do_div(count, incr);
 	start = __va(start_phys_aligned);
 	start_bad = 0;
 	last_bad = 0;
_

but I wonder why all those things are u64.  They all hold virtual
addresses, don't they?  The code doesn't test highmem.  So shouldn't
these all be unsigned longs?