Re: [PATCH v1 00/14] perf kvm: Support histograms and TUI mode

From: Arnaldo Carvalho de Melo
Date: Mon Feb 27 2023 - 16:40:25 EST


Em Sun, Feb 26, 2023 at 12:20:39PM +0800, Leo Yan escreveu:
> This patch set is to enable histograms and (partially) TUI mode in perf
> kvm tool.
>
> Current tool uses its own RB tree to maintain KVM events, it's not easy
> to extend to support more metrics and have no chance to support TUI
> mode. For this reason, we need firstly to refactor the code by using
> histograms and its associated RB tree; based on histograms we can add
> dimensions for KVM event statistics. Finally, we need to enable TUI
> mode in the tool. This is the methodology applied in this series.
>
> This series enables TUI mode for 'perf kvm stat report', but it doesn't
> support TUI mode for 'perf kvm stat live'; this is because live mode is
> different from report for TUI mode, which will be implemented in later
> (TBH, I need to look into more details in histograms for this part).
>
> Patches 01 ~ 04 are minor refactoring and they are preparation for later
> enabling histograms and dimensions.
>
> Patches 05 ~ 10 are for enabling histograms and dimensions; with these
> changes the cached list is replaced by histograms list, and we extend to
> support more sorting keys (max time, min time, mean time).
>
> Patches 11 ~ 13 are to enable TUI mode in stat report, after this patch
> TUI mode will be default mode, and user needs to input option '--stdio'
> for stdio mode rather than TUI mode.
>
> Patch 14 updates documentation for new sorting and 'stdio' mode.
>
> After changes:
>
> Please see the screenshot for the TUI with 'perf kvm stat report':
> https://people.linaro.org/~leo.yan/debug/perf/perf_kvm_stat_report_tui.png
>
> And I verified the '--stdio' mode and confirmed it has the same result
> with before applying this series.

Can you provide precise instructions for all the steps involved? from
'perf kvm record', I'm trying here with a simple 'perf kvm record' and
then starting vm and having trouble.

- Arnaldo

> # perf kvm stat report --stdio
>
>
> Analyze events for all VMs, all VCPUs:
>
> VM-EXIT Samples Samples% Time% Min Time Max Time Avg time
>
> MSR_WRITE 520 60.05% 0.07% 0.74us 16.92us 2.62us ( +- 2.66% )
> HLT 179 20.67% 99.82% 64.53us 17159.69us 10123.40us ( +- 4.68% )
> EXTERNAL_INTERRUPT 71 8.20% 0.07% 1.16us 79.63us 17.56us ( +- 10.92% )
> EPT_MISCONFIG 68 7.85% 0.03% 5.53us 64.64us 8.09us ( +- 12.50% )
> PREEMPTION_TIMER 18 2.08% 0.01% 1.91us 12.06us 5.53us ( +- 10.25% )
> INTERRUPT_WINDOW 7 0.81% 0.00% 0.91us 1.66us 1.30us ( +- 9.09% )
> MSR_READ 3 0.35% 0.00% 4.06us 4.84us 4.42us ( +- 5.11% )
>
> Total Samples:866, Total events handled time:1815367.45us.
>
> # perf kvm stat live
> 12:10:10.786799
>
> Analyze events for all VMs, all VCPUs:
>
> VM-EXIT Samples Samples% Time% Min Time Max Time Avg time
>
> MSR_WRITE 121 66.85% 12.90% 0.67us 62918.87us 667.19us ( +- 80.72% )
> HLT 34 18.78% 76.61% 2069.99us 52171.44us 14103.37us ( +- 14.25% )
> EXTERNAL_INTERRUPT 20 11.05% 10.49% 1.61us 47469.17us 3282.16us ( +- 75.75% )
> PREEMPTION_TIMER 5 2.76% 0.00% 3.98us 7.39us 5.84us ( +- 10.51% )
> INTERRUPT_WINDOW 1 0.55% 0.00% 2.01us 2.01us 2.01us ( +- 0.00% )
>
> Total Samples:181, Total events handled time:625919.05us.
>
>
> Leo Yan (14):
> perf kvm: Refactor overall statistics
> perf kvm: Add pointer to 'perf_kvm_stat' in kvm event
> perf kvm: Move up metrics helpers
> perf kvm: Use subtraction for comparison metrics
> perf kvm: Introduce histograms data structures
> perf kvm: Pass argument 'sample' to kvm_alloc_init_event()
> perf kvm: Parse address location for samples
> perf kvm: Add dimensions for KVM event statistics
> perf kvm: Use histograms list to replace cached list
> perf kvm: Polish sorting key
> perf kvm: Support printing attributions for dimensions
> perf kvm: Add dimensions for percentages
> perf kvm: Add TUI mode for stat report
> perf kvm: Update documentation to reflect new changes
>
> tools/perf/Documentation/perf-kvm.txt | 9 +-
> tools/perf/builtin-kvm.c | 847 +++++++++++++++++++++-----
> tools/perf/util/kvm-stat.h | 26 +-
> 3 files changed, 707 insertions(+), 175 deletions(-)
>
> --
> 2.34.1
>

--

- Arnaldo