kernel/linux.git/tools/perf/builtin-trace.c, branch v6.18.21

perf trace: Fix IS_ERR() vs NULL check bug

2025-09-19T15:42:07+00:00

The alloc_syscall_stats() function always returns an error pointer (ERR_PTR) on failure. So replace NULL check with IS_ERR() check after calling alloc_syscall_stats() function. Fixes: fc00897c8a3f7f57 ("perf trace: Add --summary-mode option") Reviewed-by: Ian Rogers Signed-off-by: Fushuai Wang Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf trace: Add --max-summary option

2025-09-19T15:14:29+00:00

The --max-summary option is to limit the number of output lines for syscall summary stats. The max applies to each entries like thread and cgroups. For total summary, it will just print up to the given number. For example, $ sudo perf trace -as --max-summary 3 sleep 0.1 ThreadPoolServi (1011651), 114 events, 14.8% syscall calls errors total min avg max stddev (msec) (msec) (msec) (msec) (%) --------------- -------- ------ -------- --------- --------- --------- ------ epoll_wait 38 0 95.589 0.000 2.515 11.153 28.98% futex 9 0 0.040 0.002 0.004 0.014 28.63% read 10 0 0.037 0.003 0.004 0.005 4.67% sleep (1050529), 250 events, 32.4% syscall calls errors total min avg max stddev (msec) (msec) (msec) (msec) (%) --------------- -------- ------ -------- --------- --------- --------- ------ clock_nanosleep 1 0 100.156 100.156 100.156 100.156 0.00% execve 4 3 1.020 0.005 0.255 0.989 95.93% openat 36 17 0.416 0.003 0.012 0.029 10.58% ... And this is for per-cgroup summary using BPF. $ sudo perf trace -as --max-summary 3 --summary-mode=cgroup --bpf-summary sleep 0.1 cgroup /user.slice/user-657345.slice/user@657345.service/session.slice/org.gnome.Shell@x11.service, 12 events syscall calls errors total min avg max stddev (msec) (msec) (msec) (msec) (%) --------------- -------- ------ -------- --------- --------- --------- ------ recvmsg 8 7 0.016 0.001 0.002 0.006 39.73% ppoll 1 0 0.014 0.014 0.014 0.014 0.00% write 2 0 0.010 0.002 0.005 0.008 61.02% cgroup /user.slice/user-657345.slice/session-4.scope, 73 events syscall calls errors total min avg max stddev (msec) (msec) (msec) (msec) (%) --------------- -------- ------ -------- --------- --------- --------- ------ epoll_wait 8 0 13.461 0.010 1.683 12.235 89.66% ioctl 20 0 0.204 0.001 0.010 0.113 54.01% writev 11 0 0.164 0.004 0.015 0.042 20.34% Reviewed-by: Howard Chu Signed-off-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf trace: Avoid global perf_env with evsel__env

2025-07-25T17:37:58+00:00

There is no session in perf trace unless in replay mode, so in host mode no session can be associated with the evlist. If the evsel__env call fails resort to the host_env that's part of the trace. Remove errno_to_name as it becomes a called once 1-line function once the argument is turned into a perf_env, just call perf_env__arch_strerrno directly. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250724163302.596743-19-irogers@google.com Signed-off-by: Namhyung Kim

perf machine: Explicitly pass in host perf_env

2025-07-25T17:37:57+00:00

When creating a machine for the host explicitly pass in a scoped perf_env. This removes a use of the global perf_env. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250724163302.596743-17-irogers@google.com Signed-off-by: Namhyung Kim

perf session: Add accessor for session->header.env

2025-07-25T17:37:56+00:00

The perf_env from the header in the session is frequently accessed, add an accessor function rather than access directly. Cache the value to avoid repeated calls. No behavioral change. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250724163302.596743-10-irogers@google.com Signed-off-by: Namhyung Kim

perf trace: Split BPF skel code to util/bpf_trace_augment.c

2025-06-26T17:31:05+00:00

And make builtin-trace.c less conditional. Dummy functions will be called when BUILD_BPF_SKEL=0 is used. This makes the builtin-trace.c slightly smaller and simpler by removing the skeleton and its helpers. The conditional guard of trace__init_syscalls_bpf_prog_array_maps() is changed from the HAVE_BPF_SKEL to HAVE_LIBBPF_SUPPORT as it doesn't have a skeleton in the code directly. And a dummy function is added so that it can be called unconditionally. The function will succeed only if the both conditions are true. Do not include trace_augment.h from the BPF code and move the definition of TRACE_AUG_MAX_BUF to the BPF directly. Reviewed-by: Howard Chu Tested-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/r/20250623225721.21553-1-namhyung@kernel.org Signed-off-by: Namhyung Kim

perf trace: Add missed freeing of ordered events and thread

2025-06-24T17:27:51+00:00

Caught by leak sanitizer running "perf trace BTF general tests". Make the ordered_events initialization unconditional and early so that trace__exit cleanup is simple - ordered_events__init doesn't allocate and just sets up 4 values and inits 3 list heads. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250617223356.2752099-3-irogers@google.com Signed-off-by: Namhyung Kim

perf trace: Show zero value in STRARRAY

2025-06-24T17:27:50+00:00

The STRARRAY macro is to print values in a pre-defined array. But sometimes it hides the value because it's 0. The value of 0 can have a meaning in this case so set 'show_zero' field. For example, it can show CREATE_MAP cmd in the bpf syscall. Acked-by: Howard Chu Link: https://lore.kernel.org/r/20250502204056.973977-1-namhyung@kernel.org Signed-off-by: Namhyung Kim

perf target: Remove uid from target

2025-06-09T18:18:18+00:00

Gathering threads with a uid by scanning /proc is inherently racy leading to perf_event_open failures that quit perf. All users of the functionality now use BPF filters, so remove uid and uid_str from target. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250604174545.2853620-10-irogers@google.com Signed-off-by: Namhyung Kim

perf trace: Switch user option to use BPF filter

2025-06-09T18:18:18+00:00

Finding user processes by scanning /proc is inherently racy and results in perf_event_open failures. Use a BPF filter to drop samples where the uid doesn't match. Ensure adding the BPF filter forces system-wide. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250604174545.2853620-8-irogers@google.com Signed-off-by: Namhyung Kim