From: Jens Axboe <jens.axboe@oracle.com>
To: linux-btrace@vger.kernel.org
Subject: Re: blktrace and dm devices?
Date: Thu, 30 Oct 2008 13:59:43 +0000 [thread overview]
Message-ID: <20081030135943.GU31673@kernel.dk> (raw)
In-Reply-To: <1225374971.4431.5.camel@kitka.ibm.com>
On Thu, Oct 30 2008, Martin Peschke wrote:
> Hi,
>
> I have noticed that I get C traces but no D traces for device mapper
> devices. Is blktrace supposed to handle dm devices as well?
The dispatch event is associated with request dispatching, which dm/md
does not do. You should get redirect events, telling you when the IO is
being redirected to the bottom device. Or split events.
--
Jens Axboe
prev parent reply other threads:[~2008-10-30 13:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-30 13:56 blktrace and dm devices? Martin Peschke
2008-10-30 13:59 ` Jens Axboe [this message]
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