Re: Is notify_die being overloaded?

Robin Holt
2006-04-15T10:44:10Z

On Sat, Apr 15, 2006 at 04:19:55PM +1000, Keith Owens wrote:
> Robin Holt (on Thu, 13 Apr 2006 14:46:44 -0500) wrote:
> >notify_die seems to be called to indicate the machine is going down as
> >well as there are trapped events for the process.
...
> The only real problem is the page fault handler event. All the other
...
>
> kprobes should be using its own notify chain to trap page faults, and
> the handler for that chain should be optimized away when
> CONFIG_KPROBES=n or there are no active probes.

I realize the page fault handler is the only performance critical event,
but don't all the debugging events _REALLY_ deserve a seperate call chain?
They are _completely_ seperate and isolated events. One is a minor event
which a small number of other userland processes are concerned with.
The other is indicating the machine is about stop running and is only
relevant to critical system infrastructure.

When I get back from vacation on Tuesday, I will try to work up a patch
which introduces a notify_debug() call and its call chain. Maybe that
will initiate more discussion.

Thanks,
Robin