[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20110922181216.GA13772@infradead.org>
Date: Thu, 22 Sep 2011 14:12:16 -0400
From: Christoph Hellwig <hch@...radead.org>
To: Jeff Moyer <jmoyer@...hat.com>
Cc: jens.axboe@...ionio.com, linux-kernel@...r.kernel.org
Subject: Re: blk_classic tracing horribly broken
On Thu, Sep 22, 2011 at 01:57:11PM -0400, Jeff Moyer wrote:
> Hi,
>
> I've stared at the code for a while, and I've come up empty. Would
> anyone care to take a stab at fixing this?
>
> To reproduce:
>
> mount -t debugfs none /sys/kernel/debug
> cd /sys/kernel/debug/tracing
> echo blk > current_tracer
> echo 1 > events/block/enable
> echo 1 > options/blk_classic
> echo 1 > tracing_on
>
> dd if=/dev/<device> of=/dev/null bs=1M count=1 iflag=direct
> cat trace
Why are you using this interface anyway? We actually had planned to
drop it long time ago, but for some reason that never happened.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists