Re: [PATCH 10/10 -v3][RFC] tracing: Combine event filter_activeand enable into single flags field

From: Mathieu Desnoyers
Date: Tue May 11 2010 - 10:06:07 EST


* Steven Rostedt (rostedt@xxxxxxxxxxx) wrote:
> On Mon, 2010-05-10 at 23:30 -0400, Mathieu Desnoyers wrote:
> > * Steven Rostedt (rostedt@xxxxxxxxxxx) wrote:
> > > From: Steven Rostedt <srostedt@xxxxxxxxxx>
> > >
> > > The filter_active and enable both use an int (4 bytes each) to
> > > set a single flag. We can save 4 bytes per event by combining the
> > > two into a single integer.
> > >
>
> > I would also comment about flags read-side:
> >
> > * Flags are read concurrently without locking.
>
> That can go in outside this patch set. As we discussed before, the
> filter_active which does the same today as flags does here also has the
> issue you are concerned with. IOW, this issue has nothing to do with
> this patch set, because the issue existed before the patch set and has
> not changed after the patch set.

That's fine with me.

>
> The comment should also be in Documentation, not here, since it would
> affect users more than the developers.

Typically, locking-related information belongs to comments close to the
definition. I'm not sure why you say it affects users at all.

Thanks,

Mathieu

>
> >
> > Besides that minor nit, the whole patchset has my
> >
> > Acked-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
>
> Thanks! I'll get an official release ready.
>
> -- Steve
>
>

--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
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