linux-kernel - Re: [PATCH 1/2] perf_counter: tools: Make :u and :k exclude hypervisor

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Message-ID: <20090629203443.GH31577@elte.hu>
Date:	Mon, 29 Jun 2009 22:34:43 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Paul Mackerras <paulus@...ba.org>
Cc:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] perf_counter: tools: Make :u and :k exclude
	hypervisor


* Paul Mackerras <paulus@...ba.org> wrote:

> At present, appending ":u" to an event sets the exclude_kernel 
> bit, and ":k" sets the exclude_user bit.  There is no way to set 
> the exclude_hv bit, which means that on systems with a hypervisor 
> (e.g. IBM pSeries systems), we get counts from hypervisor mode for 
> an event such as 0:1:u.
> 
> This fixes the problem by setting all three exclude bits when we 
> see the second ':' and the clearing the exclude bits corresponding 
> to the modes we want to count.  This also adds a ":h" modifier to 
> allow the user to ask for counts in hypervisor mode.
> 
> Signed-off-by: Paul Mackerras <paulus@...ba.org>
> ---
>  tools/perf/util/parse-events.c |    9 +++++++--
>  1 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 4d042f1..f2ffe2c 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -277,10 +277,15 @@ static int parse_event_symbols(const char *str, struct perf_counter_attr *attr)
>  		sep = strchr(pstr, ':');
>  		if (sep) {
>  			pstr = sep + 1;
> +			attr->exclude_user = 1;
> +			attr->exclude_kernel = 1;
> +			attr->exclude_hv = 1;
>  			if (strchr(pstr, 'k'))
> -				attr->exclude_user = 1;
> +				attr->exclude_kernel = 0;
>  			if (strchr(pstr, 'u'))
> -				attr->exclude_kernel = 1;
> +				attr->exclude_user = 0;
> +			if (strchr(pstr, 'h'))
> +				attr->exclude_hv = 0;
>  		}

Hm, mind fixing the full range of problems with these flags please?

One problem is that things like:

	--event cycles:u

dont work as expected - the u/k/h flags only work in numeric events 
which is a pity. Also, it would be nice to have an 'general' option 
to specify the context mask for all events, in some straightforward 
format like this:

	--event-mask +u+k-h

Things like that. This bit is really not well developed right now.

	Ingo
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