In place kexec

[David Woodhouse]

On Fri, 30 Jul 2010, Eric W. Biederman wrote:

> David Woodhouse <dwmw2 at infradead.org> writes:
>> The DMA gets blocked, and you don't have to worry about whether the device was
>> shut down cleanly or not. The device may be unhappy, but when the new kernel's
>> driver loads and reinitialises it, all should be forgiven.
>
> Assuming IOMMU page faults don't cause pain.  I seem to remember that
> also being a nasty issue.

Only if the driver (or the hardware) is so broken that it can't reccover. 
There's very little excuse for a driver to have that problem even at 
runtime (and fail to recover from such an error)... for a driver to fail 
to initialise the hardware even when that driver is first being loaded is 
*entirely* fucked.

Not that it doesn't happen, of course. But do we care? I lump those 
broken drivers is the same class as the ones which only work after a warm 
start from Windows or Mac OS.

-- 
dwmw2