Re: [RFC PATCH 0/7] perf: 'live mode'

From: Arnaldo Carvalho de Melo
Date: Sat Mar 27 2010 - 19:01:09 EST


Em Thu, Mar 04, 2010 at 12:18:56PM +0100, Ingo Molnar escreveu:
> * Tom Zanussi <tzanussi@xxxxxxxxx> wrote:
>
> > Currently, a perf session entails two steps: first 'perf record' or 'perf
> > trace record' records the perf data to disk, then 'perf report' or 'perf
> > trace report' reads the saved data from disk and reports the results.
> >
> > This experimental patchset makes some changes to perf that instead allow the
> > perf data to be piped directly from the record step to the report step,
> > without ever touching the disk.
>
> Very nice!
>
> > Obviously, it would be better to have a real top-like display for these
> > rather than a continuously scrolling mode like this, and of course it will
> > be much more useful once we get the syscall name injection events going (the
> > column on the left shows syscall numbers only).
>
> It's still useful for ad-hoc tracing!
>
> Side-note, it might make sense to expose the 'clear' escape sequence somehow
> in an easy fashion:
>
> 
>
> to make it non-scrolling ;-) via a pre-provided method.
>
> > There are some rough edges and inefficiencies, and I guess 'event injection'
> > may be a better way to do this in the end, but it seems to work pretty well
> > already, and I think it shows how useful such a capability can be.
>
> I'm all for it. Frederic, Steve, what do you think?

ITs really nice indeed, I'm reviewing the patches and will test them
after weekend, it fits nicely with the idea of unifying top and report,
i.e. the refresh thing he mentions could do the decay as well if a
parameter is set.

Thnaks Frederic for pointing this patchset to me.

Great work!

- Arnaldo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/