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Message-ID: <bfb1936a-7f91-089e-c8c4-f27824779fde@arm.com>
Date:   Tue, 12 Dec 2023 13:54:21 +0000
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Subject: Re: [PATCH v1 05/14] libperf cpumap: Add for_each_cpu that skips the
 "any CPU" case
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To:     Ian Rogers <irogers@google.com>
References: <20231129060211.1890454-1-irogers@google.com>
 <20231129060211.1890454-6-irogers@google.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        John Garry <john.g.garry@oracle.com>,
        Will Deacon <will@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Darren Hart <dvhart@infradead.org>,
        Davidlohr Bueso <dave@stgolabs.net>,
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        Kan Liang <kan.liang@linux.intel.com>,
        K Prateek Nayak <kprateek.nayak@amd.com>,
        Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Kajol Jain <kjain@linux.ibm.com>,
        Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
        Andrew Jones <ajones@ventanamicro.com>,
        Alexandre Ghiti <alexghiti@rivosinc.com>,
        Atish Patra <atishp@rivosinc.com>,
        "Steinar H. Gunderson" <sesse@google.com>,
        Yang Jihong <yangjihong1@huawei.com>,
        Yang Li <yang.lee@linux.alibaba.com>,
        Changbin Du <changbin.du@huawei.com>,
        Sandipan Das <sandipan.das@amd.com>,
        Ravi Bangoria <ravi.bangoria@amd.com>,
        Paran Lee <p4ranlee@gmail.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Huacai Chen <chenhuacai@kernel.org>,
        Yanteng Si <siyanteng@loongson.cn>,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
        coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
        bpf@vger.kernel.org
From:   James Clark <james.clark@arm.com>
In-Reply-To: <20231129060211.1890454-6-irogers@google.com>
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On 29/11/2023 06:02, Ian Rogers wrote:
> When iterating CPUs in a CPU map it is often desirable to skip the
> "any CPU" (aka dummy) case. Add a helper for this and use in
> builtin-record.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>

Reviewed-by: James Clark <james.clark@arm.com>

> ---
>  tools/lib/perf/include/perf/cpumap.h | 6 ++++++
>  tools/perf/builtin-record.c          | 4 +---
>  2 files changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/lib/perf/include/perf/cpumap.h b/tools/lib/perf/include/perf/cpumap.h
> index 9cf361fc5edc..dbe0a7352b64 100644
> --- a/tools/lib/perf/include/perf/cpumap.h
> +++ b/tools/lib/perf/include/perf/cpumap.h
> @@ -64,6 +64,12 @@ LIBPERF_API bool perf_cpu_map__has_any_cpu(const struct perf_cpu_map *map);
>  	     (idx) < perf_cpu_map__nr(cpus);			\
>  	     (idx)++, (cpu) = perf_cpu_map__cpu(cpus, idx))
>  
> +#define perf_cpu_map__for_each_cpu_skip_any(_cpu, idx, cpus)	\
> +	for ((idx) = 0, (_cpu) = perf_cpu_map__cpu(cpus, idx);	\
> +	     (idx) < perf_cpu_map__nr(cpus);			\
> +	     (idx)++, (_cpu) = perf_cpu_map__cpu(cpus, idx))	\
> +		if ((_cpu).cpu != -1)
> +
>  #define perf_cpu_map__for_each_idx(idx, cpus)				\
>  	for ((idx) = 0; (idx) < perf_cpu_map__nr(cpus); (idx)++)
>  
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 8ec818568662..066f9232e947 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -3580,9 +3580,7 @@ static int record__mmap_cpu_mask_init(struct mmap_cpu_mask *mask, struct perf_cp
>  	if (cpu_map__is_dummy(cpus))
>  		return 0;
>  
> -	perf_cpu_map__for_each_cpu(cpu, idx, cpus) {
> -		if (cpu.cpu == -1)
> -			continue;
> +	perf_cpu_map__for_each_cpu_skip_any(cpu, idx, cpus) {
>  		/* Return ENODEV is input cpu is greater than max cpu */
>  		if ((unsigned long)cpu.cpu > mask->nbits)
>  			return -ENODEV;