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From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no>
To: Konstantin Belousov <kostikbel@gmail.com>
References: <86bokyvtc2.fsf@ds4.des.no>
	<20120605143215.GL85127@deviant.kiev.zoral.com.ua>
Date: Tue, 05 Jun 2012 16:40:32 +0200
In-Reply-To: <20120605143215.GL85127@deviant.kiev.zoral.com.ua> (Konstantin
	Belousov's message of "Tue, 5 Jun 2012 17:32:15 +0300")
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Cc: arch@freebsd.org
Subject: Re: KTR_SPAREx
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Konstantin Belousov <kostikbel@gmail.com> writes:
> Moving all device drivers to KTR_DEV makes the KTR unusable for device
> driver debugging. When looking at the drm2 and gem traces, I do not want
> to see other devices tracepoints. Amount of data from GEM is huge, and
> obfuscating it with unrelated debugging recycles the ktr ring faster, asi=
de
> of making noise that cayses log to be meaningless.

We only have a limited number of KTR types - 32, to be precise.  We
can't spare one for each driver, and there's no reason why *your* driver
(for any value of "you") should get its own while everybody else shares
KTR_DEV.

If you think KTR_DEV is too noisy, add sysctls to enable or disable
tracing on a per-device basis.  It should be quite easy to generalize.

(I still haven't gotten around to implementing a similar infrastructure
for network interfaces...)

DES
--=20
Dag-Erling Sm=C3=B8rgrav - des@des.no