Re: [3/4] [PATCH]Diskdump - yet another crash dump function

[Ingo Molnar <mingo@elte.hu>]

* Andi Kleen <ak@muc.de> wrote:

> > yeah, this is arguably the biggest (and i think only) conceptual item
> > that needs to be solved before this can be integrated.
> 
> I would think netdump is more important than this though (so if
> anything should be integrated i would start with netdump)

i think both are important. Dumping to disks is a frequent customer
request, and not all setups can dump to a network, for performance,
security or reliability reasons. The diskdump format is the same as the
netdump format, and can be handled/analyzed by the same userspace tools,
so in this sense it's an extension of netdump to another class of IO
devices.

> > it would also be easier to enable diskdump in a driver if this was
> > handled in add_timer()/del_timer()/mod_timer()/tasklet_schedule().
> 
> I don't think it's a good idea to add this to these fast paths. Timers
> are critical for lots of things, tasklet_schedule too.
> 
> How about a standard wrapper that does the check and everybody who may
> need that uses the wrappers ?

that's what the patch does currently. It needs to be decided one way or
another. But it doesnt make alot of sense to introduce another vector of
APIs for this purpose - it would need possibly wide driver changes for
no good reason.

	Ingo