Message-ID: <bf7a4d48-ebf5-301e-5142-e728242c8b6a@intel.com>
Date:   Tue, 7 Mar 2023 15:03:17 +0200
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From:   Adrian Hunter <adrian.hunter@intel.com>
Subject: Re: [PATCH 1/8] perf bpf filter: Introduce basic BPF filter
 expression
To:     Namhyung Kim <namhyung@kernel.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Jiri Olsa <jolsa@kernel.org>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        Ian Rogers <irogers@google.com>,
        Andi Kleen <ak@linux.intel.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        Song Liu <song@kernel.org>,
        Stephane Eranian <eranian@google.com>,
        Ravi Bangoria <ravi.bangoria@amd.com>,
        Leo Yan <leo.yan@linaro.org>,
        James Clark <james.clark@arm.com>, Hao Luo <haoluo@google.com>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-perf-users@vger.kernel.org, bpf@vger.kernel.org
References: <20230222230141.1729048-1-namhyung@kernel.org>
 <20230222230141.1729048-2-namhyung@kernel.org>
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On 23/02/23 01:01, Namhyung Kim wrote:
> This implements a tiny parser for the filter expressions used for BPF.
> Each expression will be converted to struct perf_bpf_filter_expr and
> be passed to a BPF map.
> 
> For now, I'd like to start with the very basic comparisons like EQ or
> GT.  The LHS should be a term for sample data and the RHS is a number.
> The expressions are connected by a comma.  For example,
> 
>     period > 10000
>     ip < 0x1000000000000, cpu == 3
> 
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/util/Build        | 16 +++++++
>  tools/perf/util/bpf-filter.c | 37 ++++++++++++++++
>  tools/perf/util/bpf-filter.h | 36 ++++++++++++++++
>  tools/perf/util/bpf-filter.l | 82 ++++++++++++++++++++++++++++++++++++
>  tools/perf/util/bpf-filter.y | 54 ++++++++++++++++++++++++
>  5 files changed, 225 insertions(+)
>  create mode 100644 tools/perf/util/bpf-filter.c
>  create mode 100644 tools/perf/util/bpf-filter.h
>  create mode 100644 tools/perf/util/bpf-filter.l
>  create mode 100644 tools/perf/util/bpf-filter.y
> 
> diff --git a/tools/perf/util/bpf-filter.h b/tools/perf/util/bpf-filter.h
> new file mode 100644
> index 000000000000..fd5b1164a322
> --- /dev/null
> +++ b/tools/perf/util/bpf-filter.h
> @@ -0,0 +1,36 @@
> +// SPDX-License-Identifier: GPL-2.0

/* */ is preferred SPDX comment style for header files