Re: [PATCH v2 08/19] perf, tools: Expression parser enhancements for metrics

From: Jiri Olsa
Date: Tue Aug 22 2017 - 04:45:27 EST


On Fri, Aug 11, 2017 at 04:26:23PM -0700, Andi Kleen wrote:
> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
>
> Enhance the expression parser for more complex metric formulas.
>
> - Support python style IF ELSE operators
> - Add an #SMT_On magic variable for formulas that depend on the SMT
> status.
>
> Example: 4 *( CPU_CLK_UNHALTED.THREAD_ANY / 2 ) if #SMT_on else cycles
>
> - Support MIN/MAX operations
>
> Example: min(1 , IDQ.MITE_UOPS / ( UPI * 16 * ( ICACHE.HIT + ICACHE.MISSES ) / 4.0 ) )
>
> This is useful to fix up problems caused by multiplexing.
>
> - Support | & ^ operators
> - Minor cleanups and fixes
> - Support an \ escape for operators. This allows to specify event names
> like c2-residency
> - Support @ as an alternative for / to be able to specify pmus without
> conflicts with operators (like msr/tsc/ as msr@tsc@)
>
> Example: (cstate_core@c3\\-residency@ / msr@tsc@) * 100
>
> Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

thanks,
jirka