Re: [RFC][PATCH] blktrace: fix original blktrace

[Jens Axboe]

On Wed, Mar 25 2009, Li Zefan wrote:
> I'm wondering what we are going to do with the original blktrace which
> is using relay and is used via ioctl.
> 
> The problem is currently it's totally broken. You can use ftrace to see
> the output of blktrace, but user-space blktrace is unusable.
> 
> With this patch, both ioctl and ftrace can be used, but of course you
> can't use both of them at the same time.

Even if ftrace was as fast as storing huge amounts of data as blktrace,
it's still of utmost importance that nothing is broken there. There are
people actually USING this tracing to do real work, it's not a
playground.

I appreciate the efforts to unify and improve our tracing, but we must
not be breaking blktrace along the way. Otherwise the whole thing goes
back to block/blktrace.c, period.

-- 
Jens Axboe

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