Subject: Re: [RFC PATCH] LTTng instrumentation mm (updated)
From: Dave Hansen <haveblue@us.ibm.com>
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: "Frank Ch. Eigler" <fche@redhat.com>, akpm@linux-foundation.org,
       linux-kernel@vger.kernel.org, linux-mm@kvack.org, mbligh@google.com
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Date: Tue, 04 Dec 2007 12:24:23 -0800
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On Tue, 2007-12-04 at 15:05 -0500, Mathieu Desnoyers wrote:
> * Dave Hansen (haveblue@us.ibm.com) wrote:
> > On Tue, 2007-12-04 at 14:25 -0500, Mathieu Desnoyers wrote:
> > > 
> > > - I also dump the equivalent of /proc/swaps (with kernel internal
> > >   information) at trace start to know what swap files are currently
> > >   used.
> > 
> > What about just enhancing /proc/swaps so that this information can be
> > useful to people other than those doing traces?
> 
> It includes an in-kernel struct file pointer, exporting it to userspace
> would be somewhat ugly.

What about just exporting the 'type' field that we use to index into
swap_info[]?

As far as /proc goes, it may not be _ideal_ for your traces, but it sure
beats not getting the information out at all. ;)  I guess I'm just not
that familiar with the tracing requirements and I can't really assess
whether what you're asking for is reasonable, or horrible
over-engineering.  Dunno.

-- Dave

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