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

[Tom Zanussi <tzanussi@gmail.com>]

On Sat, 2010-03-27 at 20:00 -0300, Arnaldo Carvalho de Melo wrote:
> Em Thu, Mar 04, 2010 at 12:18:56PM +0100, Ingo Molnar escreveu:
> > * Tom Zanussi <tzanussi@gmail.com> 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:
> > 
> > ^[[H^[[2J
> > 
> > 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!

Thanks!  Just FYI, I have a new version of this patchset that I'm hoping
to post in the next couple of days.  It adds the refresh sequence and a
specifiable delay, among other things (like bugfixes)...

Tom

> 
> - Arnaldo