Re: [patch v3] perf tools: perf list broken on ARM
Hi Vince,
On Sat, 14 Dec 2013 15:25:18 -0500 (EST), Vince Weaver wrote:
> OK, here's an updated version that reuses evsel and hopefully doesn't leak
> memory like the previous patch I posted.
>
>
> "perf list" listing of hardware events doesn't work on older ARM devices.
> The change enabling event detection:
>
> commit b41f1cec91c37eeea6fdb15effbfa24ea0a5536b
> Author: Namhyung Kim
> Date: Tue Aug 27 11:41:53 2013 +0900
>
> perf list: Skip unsupported events
>
>
> uses the following code in tools/perf/util/parse-events.c:
>
> struct perf_event_attr attr = {
> .type = type,
> .config = config,
> .disabled = 1,
> .exclude_kernel = 1,
> };
>
> On ARM machines pre-dating the Cortex-A15 this doesn't work, as
> these machines don't support .exclude_kernel. So starting with 3.12
> "perf list" does not report any hardware events at all on older
> machines (seen on Rasp-Pi, Pandaboard, Beagleboard, etc).
>
> This version of the patch makes changes suggested by Namhyung Kim
> to check for EACCESS and retry (instead of just dropping
> the exclude_kernel) so we can properly handle machines where
> /proc/sys/kernel/perf_event_paranoid is set to 2.
>
> Reported-by: Chad Paradis
> Signed-off-by: Vince Weaver
Acked-by: Namhyung Kim
Thanks,
Namhyung
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Re: [patch v3] perf tools: perf list broken on ARM
Hi Vince,
On Sat, 14 Dec 2013 15:25:18 -0500 (EST), Vince Weaver wrote:
OK, here's an updated version that reuses evsel and hopefully doesn't leak
memory like the previous patch I posted.
perf list listing of hardware events doesn't work on older ARM devices.
The change enabling event detection:
commit b41f1cec91c37eeea6fdb15effbfa24ea0a5536b
Author: Namhyung Kim namhyung@lge.com
Date: Tue Aug 27 11:41:53 2013 +0900
perf list: Skip unsupported events
uses the following code in tools/perf/util/parse-events.c:
struct perf_event_attr attr = {
.type = type,
.config = config,
.disabled = 1,
.exclude_kernel = 1,
};
On ARM machines pre-dating the Cortex-A15 this doesn't work, as
these machines don't support .exclude_kernel. So starting with 3.12
perf list does not report any hardware events at all on older
machines (seen on Rasp-Pi, Pandaboard, Beagleboard, etc).
This version of the patch makes changes suggested by Namhyung Kim
to check for EACCESS and retry (instead of just dropping
the exclude_kernel) so we can properly handle machines where
/proc/sys/kernel/perf_event_paranoid is set to 2.
Reported-by: Chad Paradis chad.para...@umit.maine.edu
Signed-off-by: Vince Weaver vincent.wea...@maine.edu
Acked-by: Namhyung Kim namhy...@kernel.org
Thanks,
Namhyung
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