Re: [PATCH RESEND 1/2] perf tools: making coresight PMU listable

From: Adrian Hunter
Date: Wed Jul 13 2016 - 07:46:12 EST


On 17/06/16 20:02, Mathieu Poirier wrote:
> Adding the required mechanic allowing 'perf list pmu' to
> discover coresight ETM/PTM tracers.
>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>

A couple of comments below but otherwise:

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

> ---
> MAINTAINERS | 1 +
> tools/perf/MANIFEST | 1 +
> tools/perf/arch/arm/util/Build | 2 ++
> tools/perf/arch/arm/util/pmu.c | 34 ++++++++++++++++++++++++++++++++++
> tools/perf/config/Makefile | 11 ++++++++---
> 5 files changed, 46 insertions(+), 3 deletions(-)
> create mode 100644 tools/perf/arch/arm/util/pmu.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 7304d2e37a98..d3451007718b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1085,6 +1085,7 @@ F: drivers/hwtracing/coresight/*
> F: Documentation/trace/coresight.txt
> F: Documentation/devicetree/bindings/arm/coresight.txt
> F: Documentation/ABI/testing/sysfs-bus-coresight-devices-*
> +F: tools/perf/arch/arm/util/pmu.c
>
> ARM/CORGI MACHINE SUPPORT
> M: Richard Purdie <rpurdie@xxxxxxxxx>
> diff --git a/tools/perf/MANIFEST b/tools/perf/MANIFEST
> index 8c8c6b9ce915..c6683e60e603 100644
> --- a/tools/perf/MANIFEST
> +++ b/tools/perf/MANIFEST
> @@ -64,6 +64,7 @@ include/asm-generic/bitops/const_hweight.h
> include/asm-generic/bitops/fls64.h
> include/asm-generic/bitops/__fls.h
> include/asm-generic/bitops/fls.h
> +include/linux/coresight-pmu.h

tools/perf/MANIFEST has changed so you need to re-base

> include/linux/perf_event.h
> include/linux/list.h
> include/linux/hash.h
> diff --git a/tools/perf/arch/arm/util/Build b/tools/perf/arch/arm/util/Build
> index d22e3d07de3d..66ab0b05549c 100644
> --- a/tools/perf/arch/arm/util/Build
> +++ b/tools/perf/arch/arm/util/Build
> @@ -2,3 +2,5 @@ libperf-$(CONFIG_DWARF) += dwarf-regs.o
>
> libperf-$(CONFIG_LIBUNWIND) += unwind-libunwind.o
> libperf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
> +
> +libperf-$(CONFIG_AUXTRACE) += pmu.o
> diff --git a/tools/perf/arch/arm/util/pmu.c b/tools/perf/arch/arm/util/pmu.c
> new file mode 100644
> index 000000000000..af9fb666b44f
> --- /dev/null
> +++ b/tools/perf/arch/arm/util/pmu.c
> @@ -0,0 +1,34 @@
> +/*
> + * Copyright(C) 2015 Linaro Limited. All rights reserved.
> + * Author: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published by
> + * the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <string.h>
> +#include <linux/coresight-pmu.h>
> +#include <linux/perf_event.h>
> +
> +#include "../../util/pmu.h"
> +
> +struct perf_event_attr
> +*perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
> +{
> +#ifdef HAVE_AUXTRACE_SUPPORT
> + if (!strcmp(pmu->name, CORESIGHT_ETM_PMU_NAME)) {
> + /* add ETM default config here */
> + pmu->selectable = true;
> + }
> +#endif
> + return NULL;
> +}
> diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
> index 5ad0255f8756..494a672aa11d 100644
> --- a/tools/perf/config/Makefile
> +++ b/tools/perf/config/Makefile
> @@ -681,9 +681,14 @@ ifdef LIBBABELTRACE
> endif
>
> ifndef NO_AUXTRACE
> - ifeq ($(feature-get_cpuid), 0)
> - msg := $(warning Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc);
> - NO_AUXTRACE := 1
> + ifeq ($(ARCH),x86)
> + ifeq ($(feature-get_cpuid), 0)
> + msg := $(warning Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc);
> + NO_AUXTRACE := 1
> + else
> + $(call detected,CONFIG_AUXTRACE)
> + CFLAGS += -DHAVE_AUXTRACE_SUPPORT
> + endif

Maybe slightly neater to avoid duplicating lines e.g.

ifndef NO_AUXTRACE
ifeq ($(ARCH),x86)
ifeq ($(feature-get_cpuid), 0)
msg := $(warning Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc);
NO_AUXTRACE := 1
endif
endif
ifndef NO_AUXTRACE
$(call detected,CONFIG_AUXTRACE)
CFLAGS += -DHAVE_AUXTRACE_SUPPORT
endif
endif