Hi Ilpo, On 11/6/2023 9:03 AM, Reinette Chatre wrote: > On 11/6/2023 1:53 AM, Ilpo Järvinen wrote: >> On Fri, 3 Nov 2023, Reinette Chatre wrote: >>> On 11/3/2023 3:39 AM, Ilpo Järvinen wrote: >>>> On Thu, 2 Nov 2023, Reinette Chatre wrote: >>>>> On 10/24/2023 2:26 AM, Ilpo Järvinen wrote: >>>> >>>>>> Add L2 CAT selftest. As measuring L2 misses is not easily available >>>>>> with perf, use L3 accesses as a proxy for L2 CAT working or not. >>>>> >>>>> I understand the exact measurement is not available but I do notice some >>>>> L2 related symbolic counters when I run "perf list". l2_rqsts.all_demand_miss >>>>> looks promising. >>>> >>>> Okay, I was under impression that L2 misses are not available. Both based >>>> on what you mentioned to me half an year ago and because of what flags I >>>> found from the header. But I'll take another look into it. >>> >>> You are correct that when I did L2 testing a long time ago I used >>> the model specific L2 miss counts. I was hoping that things have improved >>> so that model specific counters are not needed, as you have tried here. >>> I found the l2_rqsts symbol while looking for alternatives but I am not >>> familiar enough with perf to know how these symbolic names are mapped. >>> I was hoping that they could be a simple drop-in replacement to >>> experiment with. >> >> According to perf_event_open() manpage, mapping those symbolic names >> requires libpfm so this would add a library dependency? > > I do not see perf list using this library to determine the event and > umask but I am in unfamiliar territory. I'll have to spend some more > time here to determine options. tools/perf/pmu-events/README cleared it up for me. The architecture specific tables are included in the perf binary. Potentially pmu-events.h could be included or the test could just stick with the architectural events. A quick look at the various cache.json files created the impression that the events of interest may actually have the same event code and umask across platforms. I am not familiar with libpfm. This can surely be considered if it supports this testing. Several selftests have library dependencies. Reinette
