Re: [PATCH v1 04/13] perf python: Lazily resolve sample callchains

[sashiko-bot@kernel.org]

> Previously, pyrf_event__new() eagerly resolved the sample's address
> location and callchain (including DWARF/FP unwinding and symbol lookup)
> for every sample with a callchain, even when the Python callback never
> accessed event.callchain (such as in ttimechart.py).
> 
> Move callchain resolution to pyrf_sample_event__get_callchain() so that
> callchains are only unwound and resolved when event.callchain is
> accessed, reusing the sample's cached pevent->al via
> pyrf_sample_event__resolve_al().
> 
> Because process_events() borrows the event and sample during the
> callback, callchains are never copied in the common case. Only when a
> callback retains a reference to the event beyond its return
> (Py_REFCNT(pyevent) > 1), the callchain was not already resolved during
> the callback, and the callchain is synthesized or LBR-merged (not backed
> by event_copy) does pyrf_event__copy() allocate a copy of
> sample->callchain.
> 
> Assisted-by: Antigravity:gemini-3.1-pro
> Signed-off-by: Ian Rogers <irogers@google.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20261002182624.3259797-1-irogers@google.com?part=4