Messages in this thread | | | Date | Tue, 15 Nov 2022 15:16:28 +0800 | Subject | Re: [PATCH v3 3/3] perf/x86/intel: Expose EPT-friendly PEBS for SPR and future models | From | Like Xu <> |
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On 14/11/2022 8:46 pm, Peter Zijlstra wrote: > On Wed, Nov 09, 2022 at 04:28:02PM +0800, Like Xu wrote: >> From: Like Xu <likexu@tencent.com> >> >> According to Intel SDM, the EPT-friendly PEBS is supported by all the >> platforms after ICX, ADL and the future platforms with PEBS format 5. >> >> Currently the only in-kernel user of this capability is KVM, which has >> very limited support for hybrid core pmu, so ADL and its successors do >> not currently expose this capability. When both hybrid core and PEBS >> format 5 are present, KVM will decide on its own merits. > > Oh right; the whole ADL KVM trainwreck :/ What's the plan there?
As we know, our community doesn't really have a plan in terms of feature reception, considering hyprid pmu doesn't have market share in the data center (where most KVM users are, and the test farms), and KVM-based client hypervisor will actively control the cpu that the KVM module initializes, and adds more trainwreck, so as of now I don't have a timeline for vPMU on ADL+ (until there are noteworthy user complaints).
Please let me know if you and Kan have other input.
> >> Cc: Peter Zijlstra <peterz@infradead.org> >> Cc: linux-perf-users@vger.kernel.org >> Suggested-by: Kan Liang <kan.liang@linux.intel.com> >> Signed-off-by: Like Xu <likexu@tencent.com> >> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> >> --- >> Nit: This change is proposed to be applied via the KVM tree. > > Works for me; > > Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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