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 faultWhile 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<[email protected]> Signed-off-by: John Garry<[email protected]>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<[email protected]> 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.
Anyway, can you share the full metric event which you say does not work, not just the "MetricExpr"?
Thanks, John
