> -----Original Message-----
> From: John Garry <john.ga...@huawei.com>
> Sent: 2021年1月19日 19:05
> To: Joakim Zhang <qiangqing.zh...@nxp.com>; pet...@infradead.org;
> mi...@redhat.com; a...@kernel.org; mark.rutl...@arm.com;
> alexander.shish...@linux.intel.com; jo...@redhat.com;
> namhy...@kernel.org; irog...@google.com; kj...@linux.ibm.com
> Cc: linux-kernel@vger.kernel.org; linux...@openeuler.org
> Subject: Re: [PATCH] perf metricgroup: Fix system PMU metrics
>
> On 19/01/2021 10:56, Joakim Zhang wrote:
> >> Joakim reports that getting "perf stat" for multiple system PMU
> >> metrics
> >> segfaults:
> >> ./perf stat -a -I 1000 -M imx8mm_ddr_write.all,imx8mm_ddr_write.all
> >> Segmentation fault
> >>
> >> While the same works without issue for a single metric.
> >>
> >> The logic in metricgroup__add_metric_sys_event_iter() is broken, in
> >> that
> >> add_metric() @m argument should be NULL for each new metric. Fix by
> >> not passing a holder for that, and rather make local in
> >> metricgroup__add_metric_sys_event_iter().
> >>
> >> Fixes: be335ec28efa ("perf metricgroup: Support adding metrics for
> >> system
> >> PMUs")
> >> Reported-by: Joakim Zhang<qiangqing.zh...@nxp.com>
> >> Signed-off-by: John Garry<john.ga...@huawei.com>
> > root@imx8mmevk:~# ./perf stat -a -I 1000 -M
> imx8mm_ddr_read.all,imx8mm_ddr_write
>
> .all
> > # time counts unit events
> > 1.001446500 40832
> imx8mm_ddr.read_cycles # 638.0 KB imx8mm_ddr_read.all
> > 1.001446500 16973
> imx8mm_ddr.write_cycles # 265.2 KB imx8mm_ddr_write.all
> > 2.003150250 28836
> imx8mm_ddr.read_cycles # 450.6 KB imx8mm_ddr_read.all
> > 2.003150250 6705
> imx8mm_ddr.write_cycles # 104.8 KB imx8mm_ddr_write.all
> >
> > For this issue, Tested-by: Joakim Zhang<qiangqing.zh...@nxp.com>
> >
> > Hi John,
> >
> > It seems have other issue compared to 5.10 kernel after switching to this
> framework, below metric can't work.
> > "MetricExpr": "(( imx8_ddr0@read\\-cycles@ + imx8_ddr0@write\\-cycles@ )
> * 4 * 4 / duration_time) / (750 * 1000000 * 4 * 4)"
> > After change to:
> > "MetricExpr": "(( imx8mm_ddr.read_cycles + imx8mm_ddr.write_cycles ) *
> > 4 * 4 / duration_time) / (750 * 1000000 * 4 * 4)",
>
> Hmmm... not sure what you mean by "compared to 5.10 kernel". As far as I'm
> concerned, none of this was supported in 5.10 and metrics did not work for
> arm64. Support for sys PMU events+metrics only came in 5.11-rc.
Yes, 5.10 doesn't support ARM64. I add some code let it work locally. And,
"MetricExpr": "(( imx8_ddr0@read\\-cycles@ + imx8_ddr0@write\\-cycles@ ) * 4 *
4 / duration_time) / (750 * 1000000 * 4 * 4)"
Above metric expression can work fine.
> Anyway, can you share the full metric event which you say does not work, not
> just the "MetricExpr"?
OK, Could help check below metric? Thanks.
"MetricExpr": "(( imx8_ddr0@read\\-cycles@ + imx8_ddr0@write\\-cycles@ ) * 4 *
4 / duration_time) / (750 * 1000000 * 4 * 4)"
or
"MetricExpr": "(( imx8mm_ddr.read_cycles + imx8mm_ddr.write_cycles ) * 4 * 4 /
duration_time) / (750 * 1000000 * 4 * 4)"
Best Regards,
Joakim Zhang
> Thanks,
> John
