On Thu, 8 Mar 2007, Davide Libenzi wrote: > > So, to cut it short, I can do the pseudo-siginfo read(2), but I don't > like it too much (little, actually). The siginfo, as bad as it is, is a > standard used in many POSIX APIs (hence even in kernel), and IMO if we > want to send that back, a struct siginfo should be. > No?
I think it's perfectly fine if you make it "struct siginfo" (even though I think it's a singularly ugly struct). It's just that then you'd have to make your read() know whether it's a compat-read or not, which you really can't. Which is why you introduced a new system call, but that leads to all the problems with the file descriptor no longer being *usable*. Think scripts. It's easy to do reads in perl scripts, and parse the output. In contrast, making perl use a new system call is quite challenging. And *that* is why "everything is a stream of bytes" is so important. You don't know where the file descriptor has been, or who uses it. Special system calls for special file descriptors are just *wrong*. After all, that's why we'd have a signalfd() in the first place: exactly so that you do *not* have to use special system calls, but can just pass it on to any event waiting mechanism like select, poll, epoll. The same is just *even*more*true* when it comes to reading the data! Linus - 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/