Re: [PATCH 12/12] perf kvm: add live mode

From: David Ahern
Date: Mon Oct 08 2012 - 16:54:05 EST


On 10/8/12 2:35 PM, Arnaldo Carvalho de Melo wrote:
Em Mon, Oct 08, 2012 at 11:17:36AM -0600, David Ahern escreveu:
Overall it looks good, I like the fact you're not doing it the way perf
script does, i.e. that "pipe mode" thing, more or less like I'm doing on
'perf trace', but I think this is the time to get rid of 'perf_session'
too for this specific "live mode" tools.

pipe mode would never work for this case. I'm looking at nested virt case now and it shows 360,000 events per second.

I'm almost getting there for 'trace' and 'top', just need to move the
ordered_samples code to evlist, then session, top, trace, kvm live and
script will not need to use 'perf_session' at all.

ok. you going to have that soon?

Also that 'perf_kvm__open_counters' really is just a third copy of code
in 'record' and 'top', right? You could move it to
'perf_ev{list,open}__open' and solve this dup :-)

there's a TO-DO at the top of that function for that reason ;-) I copied a fair bit from perf-stat. Now that it's working I can look at code consolidation.

I applied the cleanups/simple stuff, will try to do some of the prep
work on ordered_samples to use on top and trace and then I think you
could look there so that we get to something that is useful for all
these !perf.data tools.

On my Westmere based server I am not seeing problems with timestamps and ordering (prior testing was on a Nehalem based server). It just weathered a 5 minute or so barrage of > 100,000 events per second (peaking at around 360k events/sec) with no problem.

David
--
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/