Re: [PATCH 2/4] memory-hotplug: add node_device_release

[KOSAKI Motohiro]

> I have the reason to have to fill the node struct with 0 by memset.
> The node is a part of node struct array (node_devices[]).
> If we add empty release function for suppressing warning,
> some data remains in the node struct after hot removing memory.
> So if we re-hot adds the memory, the node struct is reused by
> register_onde_node(). But the node struct has some data, because
> it was not initialized with 0. As a result, more waning is shown
> by the remained data at hot addinig memory as follows:

Even though you call memset(0) at offline. It doesn't guarantee the memory
keep 0 until online. E.g. physical memory exchange during offline, bit
corruption
by cosmic ray, etc. So, you should fill zero at online phase explicitly if need.

The basic hotplug design is: you should forget everything at offline
and you shouldn't
assume any initialized data at online.

Thanks.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/