lwn.git - Linux kernel documentation tree maintained by Jonathan Corbet

Age	Commit message (Collapse)	Author
2026-09-29	perf python sctop: Fix offline interval printing and test flakiness	Ian Rogers
	In sctop.py: - If an earlier interval elapsed and printed an empty table before the target comm ('sleep') executed any syscalls, analyzer.printed became True and the final partial interval containing the target comm's syscalls was never flushed at EOF. Flush print_current_totals() in finally when analyzer.syscalls is non-empty as well as when nothing has been printed yet. - Initialize analyzer.e_machine after creating perf.session rather than when session is still None. In test_sctop_python.sh: - Use a private temporary directory via 'mktemp -d'. - Drop '-a' and pass '-B -N --no-bpf-event' to 'perf record', and sleep briefly in the subshell ('sh -c "sleep 0.1; sleep 0.05"') with a bounded retry loop so 'sleep's PERF_RECORD_COMM and sys_enter events are reliably captured under heavy load. Fixes: b83f0bacf5e4f936 ("perf python: Port sctop to perf module") Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-09-26	perf script: Support standalone scripts and remove embedded scripting	Ian Rogers
	Refactor 'perf script' to launch standalone scripts directly via fork() and execvp() and remove the legacy embedded Perl and Python scripting engines: - Remove the embedded Perl scripting engine (util/scripting-engines/trace-event-perl.c), Perl scripts, bin wrappers, and Trace-Util library (scripts/perl/Perf-Trace-Util/), and script_perl.sh test. - Remove libperl feature checks from Makefile.config, Makefile.perf, builtin-check.c, and Documentation/perf-check.txt. - Remove -g / --gen-script option and scripting_ops dispatch table from builtin-script.c and trace-event-scripting.c. - Hide the legacy -s / --script option and update script discovery in find_script() and list_available_scripts() to prioritize the system 'python' directory over bare filenames in the current directory. - Update the Python script shell tests (test_arm_coresight_disasm.sh, test_task_analyzer.sh, and test_*_python.sh) to invoke scripts via 'perf script <script>' rather than running the Python interpreter directly on the script file path. Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-09-26	perf python: Port sctop to perf module	Ian Rogers
	Port sctop.py from tools/perf/scripts/python/ to a standalone script in tools/perf/python/ using an SCTopAnalyzer class structure. Improvements compared to the legacy script: - Support both offline perf.data analysis (via perf.session, advancing display intervals deterministically using event timestamps) and live monitoring (via LiveSession with automatic tracepoint fallback from raw_syscalls:sys_enter to syscalls:sys_enter_*). - Resolve architecture-aware syscall names via perf.syscall_name(id, session.e_machine) without requiring python-audit. - Replace unsafe signal.SIGALRM dictionary mutation and os.popen("clear") subshell spawning with a synchronized threading.Lock / threading.Event timer and direct ANSI terminal escape sequences ('\x1b[2J\x1b[H'). Add a shell test (test_sctop_python.sh) to verify the standalone script. Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>