[PATCH 0/4] perf c2c: Add function-view stdio support and coverage
From: Jiebin Sun
Date: Fri Aug 21 2026 - 01:49:29 EST
The recently merged function-view series added an interactive TUI for
examining the c2c data as:
read-side function -> contending writer -> shared cacheline
This follow-up makes the same view available to builds without SLANG and
to pipes and scripts. `perf c2c report --function` now implies stdio and
prints the three-level hierarchy fully expanded. It requires `iaddr` in
the coalescing fields and is rejected together with `--stats`.
The first two patches fix adjacent pre-existing issues: the documented
default coalesce fields are stale, and a workload recording failure in
the existing c2c shell test is incorrectly reported as a pass. The third
patch adds the stdio function view, and the final patch adds automated
coverage using a separate contended futex workload. Systems that record
no contended samples report a skip for the hierarchy checks rather than a
spurious failure.
This series follows the function-view work merged from:
https://lore.kernel.org/linux-perf-users/20260817094623.3288456-1-jiebin.sun@xxxxxxxxx/
The series is based on perf-tools-next commit 9453bc6a69ef ("perf vendor
events arm64: Fix Tegra410 Olympus event 0x0197").
Tested with:
- SLANG and NO_SLANG=1 builds
- perf test c2c
- perf test 'import perf'
- checkpatch.pl --strict on each patch
- unresolved-symbol checks on the Python perf module
Jiebin Sun (4):
perf c2c: Fix documented default coalesce fields
perf tests c2c: Report skip when the workload fails
perf c2c: Add stdio support for the function view
perf tests c2c: Add function view stdio coverage
tools/perf/Documentation/perf-c2c.txt | 14 +++-
tools/perf/builtin-c2c.c | 85 +++++++++++++++++--
tools/perf/tests/shell/c2c.sh | 114 ++++++++++++++++++++++++++
tools/perf/util/c2c-function.c | 9 +-
tools/perf/util/c2c.h | 1 +
5 files changed, 205 insertions(+), 18 deletions(-)
base-commit: 9453bc6a69ef43755f1c28d5688cacdd69fa16bd
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2.52.0