Messages in this thread | | | From | Ian Rogers <> | Date | Wed, 29 Sep 2021 09:09:24 -0700 | Subject | Re: [PATCH v9 00/13] Don't compute events that won't be used in a metric. |
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On Wed, Sep 29, 2021 at 8:16 AM John Garry <john.garry@huawei.com> wrote: > > On 23/09/2021 08:46, Ian Rogers wrote: > > For a metric like: > > EVENT1 if #smt_on else EVENT2 > > > > currently EVENT1 and EVENT2 will be measured and then when the metric > > is reported EVENT1 or EVENT2 will be printed depending on the value > > from smt_on() during the expr parsing. Computing both events is > > unnecessary and can lead to multiplexing as discussed in this thread: > > https://lore.kernel.org/lkml/20201110100346.2527031-1-irogers@google.com/ > > > > This change modifies expression parsing so that constants are > > considered when building the set of ids (events) and only events not > > contributing to a constant value are measured. > > Based on some testing on my arm64 platform, no regression seen, so: > > Tested-by: John Garry <john.garry@huawei.com>
Awesome, much thanks Jiri, John, Andi for the reviews and testing!
Ian
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