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Date: Sat, 29 Apr 2006 09:08:26 +0200
From: Heiko Carstens <heiko.carstens@de.ibm.com>
To: Heiko J Schick <info@schihei.de>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>,
       Michael Ellerman <michael@ellerman.id.au>,
       J?rn Engel <joern@wohnheim.fh-wedel.de>, linux-kernel@vger.kernel.org,
       openib-general@openib.org, linuxppc-dev@ozlabs.org,
       Christoph Raisch <RAISCH@de.ibm.com>,
       Hoang-Nam Nguyen <HNGUYEN@de.ibm.com>, Marcus Eder <MEDER@de.ibm.com>
Subject: Re: [openib-general] Re: [PATCH 04/16] ehca: userspace support
Message-ID: <20060429070826.GA9463@osiris.boeblingen.de.ibm.com>
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> >>The problem I see with pr_debug() is that it could only activated via
> >>a compile flag. To use the debug outputs you have to re-compile /
> >>compile your own kernel.
> >
> >Do you really need this heavy debug logging in the first place? You
> >can use kprobes for arbitrary run-time inspection anyway, so logging
> >everything seems wasteful.
> 
> The problem I see with kprobes is that you have to set several kernel
> configuration options (e.g. CONFIG_KPROBES, CONFIG_DEBUG_INFO, etc.)
> on compile time to use it. Same problem with pr_debug().

It might be worth to move the s390 debug feature to common code. At least
it has proven many times to be very useful in device driver debugging...
See Documentation/s390/s390dbf.txt and arch/s390/kernel/debug.c.