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

From: Leo Yan
Date: Sat Feb 25 2023 - 23:21:14 EST

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.

# 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