Re: [External] : [RFC PATCH v2 1/6] perf vendor events arm64: Add topdown L1 metrics for neoverse-n2
From: John Garry <john.g.garry@oracle.com>
Date: 2022-11-14 13:01:28
Also in:
linux-perf-users, lkml
From: John Garry <john.g.garry@oracle.com>
Date: 2022-11-14 13:01:28
Also in:
linux-perf-users, lkml
On 14/11/2022 07:41, Jing Zhang wrote:
The calculation formula of topdown L1 is from the document: https://urldefense.com/v3/__https://documentation-service.arm.com/static/60250c7395978b529036da86?token=__;!!ACWV5N9M2RV99hQ!Ll-Jgvfs0LitTCU-hC6i6BKBVJfhke-pbQq2VoO-gmuSAcglQ3ZqMVMd2r0An_5a3ZDPYmn8zXuCrpUbehwnLHplVQ$
So since this is a from "standard" document, did you consider putting these as an arch std event? I think arch std events would work for metrics, like they do for regular events.
However, due to the wrong count of stall_slot and stall_slot_frontend in neoverse-n2, the real stall_slot and real stall_slot_frontend need to subtract cpu_cycles, so when calculating the topdownL1 metrics, stall_slot and stall_slot_frontend are corrected.
Is there a reference to this? It would be indeed useful to pass a link to the n2 doc as these metrics are not part of the arm64 arm. At least I assume that they are not there.
Since neoverse-n2 does not yet support topdown L2, metricgroups such as Cache, TLB, Branch, InstructionsMix, and PEutilization will be added to further analysis of performance bottlenecks in the following patches.
Thanks, John _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel