Jens Axboe <axboe@suse.de> wrote:
>
> Hi,
>
> The patch doesn't look right, why is INITIAL_JIFFIES being cast to
> unsigned int? This breaks x86_64 at least.
>
> ...
> -#define INITIAL_JIFFIES ((unsigned int) (-300*HZ))
This sets the initial jiffies value to 0x00000000fffb6c20, which can trigger
32-bit wraparound bugs: if some random jiffy counter wraps from
0x00000000ffffffff to 0x0000000000000000 then things fail.
davem was bitten by at least one such bug in the qlogicfc driver. It would
have caused 64-bit machines to fail after 49 days.
It turns out that it is more valuable to test for this than to test for
64-bit wraparound bugs.
-
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/
This archive was generated by hypermail 2b29 : Fri Mar 07 2003 - 22:00:36 EST