From: Andi Kleen <ak@suse.de>
To: "Jan Beulich" <jbeulich@novell.com>
Subject: Re: notify_page_fault_chain
Date: Mon, 7 Aug 2006 15:36:40 +0200
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On Monday 07 August 2006 15:22, Jan Beulich wrote:

> I just noticed this addition to i386 and x86-64, conditionalized upon CONFIG_KPROBES. May I ask what the motivation for
> this compatibility breaking change is?

It's normally policy to only care about in tree code regarding exports and hooks.
But also no policy without exceptions.

> Only performance?

Christopher L. complained about it taking too long on IA64 I think
(but that might have been some IA64 specific quirk)

I think I proposed to use a inline check of the chain and only then
call the external function, but that might not have been implemented
that way.

> I consider it already questionable to split out a specific  
> fault from the general die notification (previous users of the functionality all of the sudden won't get notifications
> for one of the most crucial faults anymore), but entirely hiding the functionality (unavailable without CONFIG_KPROBES,
> and even with it not getting exported) is really odd.

You want to use it for your debugger? 

-Andi
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