On 4/11/07, Zach Brown <[EMAIL PROTECTED]> wrote:
> Sorry I wasn't thorough enough. And partially because I was worried > about changing structure type for user space facing struct aio_ring. > Now that I looked through all arches, it looks safe as all arch's > atomic_t has the same size as int.> Here is the updated patch. > @@ -144,7 +144,7 @@ struct kiocb { > struct aio_ring { > unsigned id; /* kernel internal index number */ > unsigned nr; /* number of io_events */ > - unsigned head; > + atomic_t head; > unsigned tail; Embedding an atomic_t in an ABI struct? That makes everyone else nervous too, right?
sure, make me nervous at least.
It may look safe on i386/x86-64 today, but this doesn't seem like wise practice. Is there any reason to believe that atomic_t will never change size? Does anything else do this already? If nothing else, the "unsigned" (should be __u32, sigh) could be cast to an atomic_t.
The atomic_t cast is equally iffy. I don't know what would be a best solution. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
