From: Leo Yan <leo.yan@linaro.org>
To: James Clark <james.clark@arm.com>
Cc: acme@kernel.org, mathieu.poirier@linaro.org,
coresight@lists.linaro.org, linux-perf-users@vger.kernel.org,
suzuki.poulose@arm.com, mike.leach@linaro.org,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
John Garry <john.garry@huawei.com>, Will Deacon <will@kernel.org>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC PATCH 6/6] perf cs-etm: Add warnings for missing DSOs
Date: Mon, 2 Aug 2021 23:41:45 +0800 [thread overview]
Message-ID: <20210802154145.GC148327@leoy-ThinkPad-X240s> (raw)
In-Reply-To: <20210729155805.2830-7-james.clark@arm.com>
On Thu, Jul 29, 2021 at 04:58:05PM +0100, James Clark wrote:
> Currently decode will silently fail if no binary data is available for
> the decode. This is made worse if only partial data is available because
> the decode will appear to work, but any trace from that missing DSO will
> silently not be generated.
>
> Add a UI popup once if there is any data missing, and then warn in the
> bottom left for each individual DSO that's missing.
>
> Signed-off-by: James Clark <james.clark@arm.com>
> ---
> tools/perf/util/cs-etm.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index 32ad92d3e454..e6851260d059 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -746,8 +746,16 @@ static u32 cs_etm__mem_access(struct cs_etm_queue *etmq, u8 trace_chan_id,
>
> len = dso__data_read_offset(al.map->dso, machine, offset, buffer, size);
>
> - if (len <= 0)
> + if (len <= 0) {
> + ui__warning_once("CS ETM Trace: Missing DSO. Use 'perf archive' to export data from the traced system.\n");
> + if (!al.map->dso->auxtrace_warned) {
> + pr_err("CS ETM Trace: Debug data not found for address %#"PRIx64" in %s\n",
> + address,
> + al.map->dso->long_name ? al.map->dso->long_name : "Unknown");
> + al.map->dso->auxtrace_warned = true;
> + }
This is very useful.
Just one comment: in particularly if the perf fails to find the kernel
symbols, the user needs to enable config "CONFIG_PROC_KCORE=y" or
specify option "-k /path/to/vmlinux". In this case, using 'perf
archive' is not helpful. So I think the UI warning can be imporved
like:
ui__warning_once("CS ETM Trace: Missing DSO. Use 'perf archive' to export data from the traced system.\n"
" Enable CONFIG_PROC_KCORE or use option '-k /path/to/vmlinux' for kernel symbols\n");
With this improvement, the patch looks good to me:
Reviewed-by: Leo Yan <leo.yan@linaro.org>
> return 0;
> + }
>
> return len;
> }
> --
> 2.28.0
>
next prev parent reply other threads:[~2021-08-02 15:41 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-29 15:57 [RFC PATCH 0/6] perf tools: Warning fixes James Clark
2021-07-29 15:58 ` [RFC PATCH 1/6] perf tools: Add WARN_ONCE equivalent for UI warnings James Clark
2021-08-02 14:44 ` Arnaldo Carvalho de Melo
2021-07-29 15:58 ` [RFC PATCH 2/6] perf tools: Re-add annotate_warned functionality James Clark
2021-07-29 15:58 ` [RFC PATCH 3/6] perf tools: Add disassembly warnings for annotate --stdio James Clark
2021-07-29 15:58 ` [RFC PATCH 4/6] perf tools: Add flag for tracking warnings of missing DSOs James Clark
2021-07-29 15:58 ` [RFC PATCH 5/6] perf cs-etm: Improve Coresight zero timestamp warning James Clark
2021-08-02 15:17 ` Leo Yan
2021-08-03 13:25 ` Arnaldo Carvalho de Melo
2021-07-29 15:58 ` [RFC PATCH 6/6] perf cs-etm: Add warnings for missing DSOs James Clark
2021-08-02 14:51 ` Arnaldo Carvalho de Melo
2021-08-02 17:03 ` Mathieu Poirier
2021-08-03 8:06 ` Mike Leach
2021-08-02 15:41 ` Leo Yan [this message]
2021-08-03 13:24 ` Arnaldo Carvalho de Melo
2021-08-03 14:01 ` Leo Yan
2021-08-05 12:59 ` James Clark
2021-08-06 18:36 ` Arnaldo Carvalho de Melo
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