Re: [PATCH v3 1/2] perf test: Workload test of metric and metricgroups

From: John Garry
Date: Wed Jan 12 2022 - 07:25:02 EST


On 24/09/2021 20:09, Arnaldo Carvalho de Melo wrote:
Em Fri, Sep 17, 2021 at 11:42:39AM -0700, Ian Rogers escreveu:
Test every metric and metricgroup with 'true' as a workload. For
metrics, check that we see the metric printed or get unsupported. If the
'true' workload executes too quickly retry with 'perf bench internals
synthesize'.

v3. Fix test condition (thanks to Paul A. Clarke<pc@xxxxxxxxxx>). Add a
fallback case of a larger workload so that we don't ignore "<not
counted>".
v2. Switched the workload to something faster.

Hi Ian,

I just noticed that this test fails on my broadwell machine.

I am using acme perf/core @ 09dd3c22daaf

metricgroup Memory_Bw fails, and it seems because of the "true" argument to "perf stat" (or any argument, like sleep 1):

john@localhost:~/kernel-dev9/tools/perf> sudo ./perf stat -M Memory_BW
^C
Performance counter stats for 'system wide':

2,184 arb/event=0x84,umask=0x1/ # 0.26 DRAM_BW_Use
2,954,938 arb/event=0x81,umask=0x1/
736,368,852 ns duration_time
58,202,980 l1d_pend_miss.pending_cycles # 2.34 MLP (80.11%)
136,293,194 l1d_pend_miss.pending (19.89%)
736,368,852 ns duration_time
1,065,656 longest_lat_cache.miss # 0.09 L3_Cache_Fill_BW (39.71%)
736,368,852 ns duration_time
5,365,477 l2_lines_in.all # 0.47 L2_Cache_Fill_BW (59.80%)
736,368,852 ns duration_time
3,557,362 l1d.replacement # 0.31 L1D_Cache_Fill_BW (79.90%)
736,368,852 ns duration_time

0.736368852 seconds time elapsed


john@localhost:~/kernel-dev9/tools/perf> sudo ./perf stat -M Memory_BW true
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (arb/event=0x84,umask=0x1/).
/bin/dmesg | grep -i perf may provide additional information.

john@localhost:~/kernel-dev9/tools/perf>

Anyone any idea on this before I start digging?

Thanks,
John