Re: [PATCH 10/13] perf kvm: add live mode

From: David Ahern
Date: Thu May 09 2013 - 09:54:35 EST


On 5/9/13 2:51 AM, Ingo Molnar wrote:
1)

Regarding the basic syntax - is the 'perf stat kvm' command already used
up? If not then it might make sense to alias 'perf kvm stat live' to 'perf
kvm stat', making it really easy to use:

perf kvm stat
perf kvm stat -p <pid>

etc. I'd expect most 'perf kvm stat' users to utilize this syntax - so it
makes sense to make 'live' the default and main command.

The default is for 'perf kvm stat' to call cmd_stat (i.e, perf kvm stat == perf stat with perf_guest flag set to 1).


2)

Another suggestion: it would be nice to allow a "--repeat <n>" option as
well, for a limited number of iterations - similar to what the 'top' tool
allows:

top -b -d <delay> -n <iterations>

--repeat 0 means infinite repeats, --repeat 1 means a single step.

Missed that option in perf-top. Let me take a look at it.

3)

It might make sense to create 'perf kvm stat top' which is a small
variation to 'perf kvm stat live': it outputs a perf stat output per
second, but also outputs a clear-screen sequence before the output.

To keep it simple you could do this with plain console text output, not
libslang, the C code to generate a clear screen sequence can be generated
via this shell oneliner:

echo 'prinf("'$(clear)'");' > clearscreen.c

This way people could see constantly updating top-alike KVM statistics.

Ok, once the basic live command is pulled into Arnaldo's tree I can look at variations like these last 2 suggestions.

David
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