On Tue, Mar 01, 2005 at 10:08:48AM -0800, Linus Torvalds wrote: > The thing is, IO errors just will be very architecture-dependent. Some > might have exceptions happening, without the exception handler really > having much of an idea of who caused it, unless that driver had prepared > it some way, and gotten the proper locks.
A lot of architectures will move towards PCI Express over the next years, and it has nice standardized error handling. It won't work on a lot of older chipsets, but having such a feature only on new hardware is ok. > A non-converted driver just doesn't _do_ any of that. It doesn't guarantee > that it's the only one accessing that bus, since it doesn't do the > "iocheck_clear()/iocheck_read()" things that imply all the locking etc. It just reads 0xffffffff all the time and moves on. That will not be nice, but work for a short time until a higher level error handler can take over. > > So the default handling for iochecks pretty much _has_ to be "report them > to the user", and then letting the user decide what to do if the hardware > is going bad. Not with PCI Express. There is a standard way now to figure out which device went bad and you can get interrupts for it. > > Shutting down the hardware by default might be a horribly bad thing to do > even _if_ you could pinpoint the driver that caused the problem in the > first place (and that's a big if, and probably depends on the details of > what the actual hw architecture support ends up being). So don't even try. > The sysadmin may have different preferences than some driver default. There are already architectures that do it (e.g. IBM ppc64 or HP zx*). It doesn't work too badly for them. > > In fact, I'd argue that even a driver that _uses_ the interface should not > necessarily shut itself down on error. Obviously, it should always log the > error, but outside of that it might be good if the operator can decide and > set a flag whether it should try to re-try (which may not always be > possible, of course), shut down, or just continue. Ok, maybe an /sbin/hotplug like interface may make sense for it. However shutdown as default is not too bad. -Andi - 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/
