On Thu, 8 Mar 2007, Linus Torvalds wrote: > > > 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!
"Cheeseburger it is!" ;) I'll revert back to read(2) with pseudo-siginfo and O_NONBLOCK handling... - Davide - 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/
